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Types of Quantum Computing Technology
Types of Quantum Computing Technology
With the increased use of quantum computing comes the rise in related technologies.
Silicon
Silicon-based technology relies on quantum dots carved out of silicon. This can achieve high-density qubits which can scale up to large numbers and tackle practical quantum computing problems. This uses traditional silicon wafer fabing techniques for development. The goal is to spin qubits on silicon at the atomic scale.
Ionic
Ionic-based technology uses charged atomic particles, which can be confined and suspended in free space using electromagnetic fields. Qubits are stored in the stable electronic states of each ion. Lasers are used to induce coupling between qubits. With ion-based technology there is the potential for scalable trapped ion quantum computers.
Carbon
Carbon-based technology is a suspended carbon nanotube coupled to a quantum dot, making a mechanical oscillator that serves as a qubit. This technology is based on grown carbon nano tubes that combine spins to ensure long coherence times and high frequency microwave components to enable fast operations. Carbon technology might be a way to reduce error rates and therefore would be useful in “noisy” quantum environments.
Photonic
Photonic-based technology consists of superpositions of multiple photons in a light pulse. Qubits consist of so-called “squeeze states” consisting of superpositions of multiple photons in a light pulse. The squeezed light and optical gates use silicon design techniques. Photonic technology can help scale quantum computers to millions of qubits. Qubits can be made with photons or single particles of quantum computing platforms.
Superconducting
Superconducting-based technology is photons and/or exotic states of matter trapped in magnetic fields. When temperatures drop, the laws of physics change, and the particles allow for faster computation. Superconduction occurs in cryogenic applications; this places extreme demand on interconnect materials, which means custom materials are needed, as standard coax will not survive.
Hybrid
Hybrid technology is a combination of classical computing and quantum computing. It combines elements of quantum computing, especially the use of quantum bits or qubits for processing, and classical computers as we already know them.
The Difference Between Classical and Quantum Computing
The Difference Between Classical and Quantum Computing
Both classical and quantum computing process data. The difference lies in the methods and the speed of each type of computing. Although quantum computing is becoming more widely used, it will not replace classical computing; it can, however, do some things that classical computing cannot. Getting the computing power that many industries need is increasingly less possible with classical computing, which is where quantum computing comes in.
Classical Computing
A classical computer uses bits to represent data for binary processing, which has states of either 0 or 1. This eliminates any ambiguity and makes data easily predicable and replicable. A classical CPU is silicon based with transistor logic and requires external memory. Classical computing power increases linearly as a function of computing power, based on the number of transistors and bits; this allows classical computers to have good speed with parallel processing and algorithms.
Quantum Computing
Quantum computing works using the quantum properties of atomic and subatomic particles. The primary element for computations is called a quantum bit or qubit. A quantum computer CPU is atomic, ionic, or photonic. They can be incredibly powerful while using a fraction of the energy of a classical computer. Quantum computing power also increases exponentially with each additional qubit.
Quantum computing uses two main properties from quantum physics: superposition and entanglement. Qubit processing with a quantum computer allows for multiple superposition states where a qubit can either be a 0, a 1, or both simultaneously. This property enables a quantum computer to process information significantly faster and more efficiently than a classical computer. Quantum computing also uses the principle of entanglement, where one qubit can be in a state and when coupled with another qubit, their states mimic each other without physical contact. Entanglement allows for true parallel processing.
What is Quantum Computing?
What is Quantum Computing?
First theorized in the 1980s, quantum computing is the next frontier of computation, representing a significant shift in computing performance capabilities. As quantum becomes more prevalent in research, this type of computing will save years of development time and a substantial amount of money in engineering design.
The main use cases for quantum computing are applications with complex problems and complicated operations involving thousands of inputs. These types of applications can include:
- Global Shipping Logistics
- Cybersecurity
- Financial and Economic Modeling
- Aerodynamic and Thermodynamic Modeling
- Cosmology Simulation
To keep quantum computers stable, they need to be exceptionally cold—typically colder than the vacuum of space. The performance capabilities inherent in quantum computing require robust RF interconnects and cable assemblies to transport data (qubits) to and from the computer reliably.
Quantum Computing and Times Microwave Systems
Quantum computers require specialized cabling solutions such as rugged, low-loss, and phase stable coaxial assemblies. The RF cable assemblies these systems rely on must be custom built to customer specifications, with specific bend radii and lengths. Quantum computing also requires signal access points close to processors and non-magnetic cables to eliminate potential interference with applied magnetic fields.
At Times Microwave Systems, we build cabling products for the most challenging environments on the planet, including the extreme temperatures of the cryo-chamber, which can reach zero degrees Kelvin. Our hermetically sealed custom coaxial cabling assemblies address the need for reliable performance in grueling environments by utilizing advanced manufacturing techniques that ensure zero electric field distortion.

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Frequency Matters Podcast: Quantum Computing with Dave Slack
Frequency Matters Podcast: Quantum Computing with Dave Slack
Summary
Gary Lerude of Microwave Journal recently spoke with Dave Slack, Engineering Director at Times Microwave Systems, on quantum computing. Watch the complete video or read the session notes below.
Session Notes
What is quantum computing?
Quantum computing has been in development for a couple of decades now but it’s really starting to heat up for several reasons. I compare it to classical computing. With classical computing we’re all familiar with we use ones and zeros and binary data. Quantum computing works using the quantum properties of atomic and subatomic matter. It uses those very strange quantum properties and it’s pretty interesting technology.
I tend to look at new technologies like this in a historical context because I find you can look at what has happened and play that forward and get a pretty good understanding of how things are going to play out in the upcoming years. If you look back at the development of classing computing right in 1951, the U.S. Census Bureau took delivery of a machine called Univac. This Univac was room sized, it was sixty thousand pounds, 5,000 vacuum tubes, and it could perform calculation at a massive 1,000 calculations per second. We processed that as a kilohertz. Today we have hundreds of megahertz computing power in our pockets that we’re just carrying around with us so quite a gap has been covered in that period. From 1951 with the vacuum tubes, in the late 50s transistors were introduced; in the 60s and 70s those transistors were integrated into integrated circuits. 1980s microprocessors came along and computers got more and more powerful and they got smaller and smaller and smaller. 1965 a gentleman named Gordon Moore put out Moore’s law, that the transistor density of chips would double every year and that has that has been true from 1965 until about 2010.
In 2010 Moore’s Law started to trail off, meaning that the technology behind classical computing is starting to reach it’s the limits of physics and the limits of economics. To get the computing power that you know many industries need is going to be increasingly less possible with classical computing. Classical computing, as we mentioned earlier, uses very discrete ones and zeros. No ambiguity. It’s either/or, nowhere in the middle. It’s very predictable, it’s very reproducible. Quantum physics uses the properties of quantum, of quantum mechanics, which is the mechanics of matter very, very microscopic scales.
The basic element for computations is called a quantum bit or qubit. Qubit can be it can be a one or a zero, but it actually shouldn’t be thought of as a one and a zero because it can be both which is kind of which is kind of weird when you think about it. And quantum mechanics also use the principle of entanglement, where one qubit can be in a state and it will be coupled with another qubit their states will kind of mimic each other without any physical connection, which is super weird.
When I try to get my head around how can a bit of data be a one and a zero that’s really hard for me to grasp, so I think of it, being a microwave guy, I think of it in terms of noise. I think about that spectrum analyzer with no inputs and you set your filters up and you get noise for down 130, 140 dbm, and you see the randomness, you just see random noise. And you could park a market at any frequency you want to and you’re going to get this range of noise values. You know, they’re going to be all over the place. So you cannot say that if I put a marker at five gigahertz, I am going to measure power X. it’s just not that deterministic like you would expect in a classical computing world. Being a one or a zero, what you’re going to see is a range of numbers and if you capture those numbers over time you can describe them statistically. You will have X probability of measuring Y value every time you sample. It’s about the best you can do. And that’s the way I think of a quantum bit or qubit being a one and a zero. If you’re controlling it and it should be in the one state you know statistically it’s going to tend to be in the one state but it could be in a zero or anywhere in between. It’s only what it is when I measure it is what matters. Quantum computing takes advantage of both of those properties, the superposition properties of the one and the zero and the entanglement properties. The entanglement kind of gives you true parallel processing, so whereas classical computing power increases linearly as a function of computing power, the number of transistors and number of bits, quantum computing increases exponentially with the number of qubits so they can be massively more powerful with every time you add on another bit. They have the ability to be super powerful with a fraction of the energy usage.
So I’m with you so far, that makes sense. I like your analogy of the kind of noise floor on a spectrum analyzer to try to understand the probabilistic nature. If we think about more practical terms, you talked about the power of quantum computing, but what would a quantum computer be able to do?
First of all what they will not do is replace classical computing. We’re always going to have that. That’s always going to be the best tool for many, many calculations. What quantum computing will do is it allows the use of different bits. It uses different algorithms and works totally differently and what it will allow you to do is take problems that have a massive number of inputs and where these inputs are not always discreetly defined they’re more statistical inputs, and it will allow you to process problems like that because that’s the way the machines thinks and works.
The use cases that are seen for this is anything where a large number of complex numbers are involved, like cybersecurity, security, banking security, financial and economic modeling. If you try to get two economists to agree on what the economy is going to do their models are limited in what they can do so the quantum computer is really geared towards that kind of a complex problem with thousands and thousands of inputs into it. Predicting the weather, you can never get two weathermen to agree on what the weather is going to do. It’s super complicated modeling climate change. All these super complex models are where I think quantum computing has a fit.
I think artificial intelligence is just going to explode when it has access to this tool. And the other thing is you know aerodynamic and thermodynamic modeling, especially with hypersonic weapons, that modeling of those thermodynamics and the aerodynamics at those speeds and velocities aren’t well known, so today they’re doing a lot of physical testing to kind of understand. They run models that takes weeks to complete. Having a quantum computer to run those models would be way less physical testing and they could run more models much more quickly would be super valuable.
That makes sense, a lot of power involved there particularly with very complex problems. Now, we hear that there’s a connection between quantum computing and microwave engineering. How is microwave engineering involved in quantum computing?
That’s the question for this audience, I’m sure. So how do we play in this? The qubits, you can think of the qubits as a microwave resonator like an LC tank or something, and you can drive these qubits from a zero state to a one state, to one energy level zero or a one, by driving it with a microwave signal. It’s a resonant and you drive it with a signal at that frequency of resonance and you’re going to change the energy level within that resonator. Under this driven condition the probabilities of being a one or a zero vary sinusoidally with time and it could be controlled too much the way other signal can be controlled. It’s important to know that like other signals, the qubits have magnitude and a phase relationship. They’re complex signals, so it’s very familiar to the microwave community these concepts.
One of the limiting factors in quantum computing is when you have this resonator under this driven condition, it’s kind of predictable and controlled and is only able to be maintained for a certain period of time because with any resonator there’s losses and there’s things affect it that cause it to lose energy and stop resonating. And that’s the limiters here. That is called the correlation of the qubit. When these things become de-correlated they’re no longer predictable, they’re no longer controlled, and that’s analogous to bit errors in data, so you’d have computational issues. The correlation and the control of the qubits is one of the real driving issues behind the technology development. What it really boils down to is the noise comes from thermal noise, it comes from magnetic noise, and it can come from mechanical noise, vibrations, things like that. Microwave hardware that can feed these resonators and minimize these contaminations. In fact, one of the prime limitations is super low noise driving signals for the qubits, especially low phase noise, so a lot of work is going on to ultra low phase noise oscillators and things like that.
The way to have a computer, you need more than one bit so you have two bits or multiple bits; when you have two of these bits they can be coupled together and they can be controlled by this driving signal which is at a microwave frequency, and it can be amplitude and phase modulated to give it certain properties. Both qubits can be modulated separately, and then using the wave properties of the two you can get it to perform in certain ways and the wave properties actually interfere. It’s very analogous to interferometry that antenna and radar people do.
I think of it again in terms of that classic high school demonstration of the two slits and the laser beam and you get the interferometry pattern, you get areas where the two wave patterns can interfere constructively and then others where they interfere destructively. You get kind of high-density probabilities and low density probabilities. You get essentially the ones and zeros and those can be controlled. All of the hardware that’s used to control these qubits and this coupling, I’ll introduce these noises, the thermal, the magnetic, the vibrational noise, so aside from the low noise sources of these driving signals in precise modulation schemes it’s hardware that minimizes that contamination. This is where I think a lot of the microwave community can support.
I think one of the requirements to maintain low noise is to have very low temperatures. Is that correct?
Absolutely. The resonators, the lump constant model is an inductor in parallel with a capacitor. And if you have that you have this perpetual motion machine that just the magnetic flux collapses drives the capacitor which then charges and then discharges and repeat. That would go on forever on paper but in reality there’s losses, these resistive losses, so you get kind of a damp sine wave unless you feedback some of that energy with this driving signal. Being at cryogenic temperatures, below 4 miliKelvin, which is really close to absolute zero, which also astounds me that we can get things that cold, but you minimize resistive losses. It’s virtually zero so you don’t have those losses. The noise floor is less so thermal noise is less. The quantum computing actually wants to happen in a really hard vacuum at super cold temperatures and totally shielded from the Earth’s magnetic field. It’s a very pristine place that these computations want to take place.
You’ve convinced me that there’s a lot of potential here. What’s the actual state of the technology and capability today? I know there’s a lot of research going on, but where are we?
The way I see it, we are in the period before Univac was delivered to its customer. We don’t quite have that Univac machine, that big room-sized monster. The first time commercial quantum computers are going to be quite analogous to that and I think over time they’re going to do what classic computers have done, they’re going to get smaller and faster and more accurate very quickly. I think in the decades that have spanned between then and now, I think that development time frame is going to be a fraction of what it was. I think the next five years are going to be astounding. Next year is going to be a big year and the next ten years is just going to be amazing at where the development is.
Google is spending billions of dollars on this and they have recently just claimed supremacy; they’ve proclaimed there’s a computer problem that Google’s quantum computer has solved in 200 seconds that they claim that IBM Summit machine would take 10,000 years to solve which is an astounding claim. IBM of course disputes this. IBM says that now it would take our Summit computer two and a half days to solve this problem, so by IBM’s own numbers it’s taken a two and a half day solution can now be done in 200 seconds which a thousand to one improvement. And this is on that pre, this is on that lab level computer. So if we can get a thousand time improvement of our quantum Univac , the next five or ten years I mean only the imagination is our limits. I think ti’s going to be a really interesting ride and I’m really looking forward to seeing it unfold.
Hypersonic Missiles Demand Unique Coaxial Cable
by Dave Murray, Technical Fellow
Originally published in Microwave Product Digest
Hypersonic missiles represent the most significant advancement in defense weaponry since the 1960s. However, they also present substantial challenges. The term “hypersonic” describes any speed faster than five times the speed of sound (above Mach 5). In fact, these missiles are so fast that, as they travel, their speed can alter the adjacent air molecules. Compared to ballistic missiles, which are fast but travel along a predictable trajectory, and cruise missiles, which are accurate but slower, hypersonic weapons combine speed and accuracy. In addition, they are low-flying and maneuverable, designed to be nimble enough that traditional missile defense systems cannot detect and react in time.
There are two types: hypersonic glide vehicles (HGVs), also known as boost-glide vehicles, are typically launched from a ballistic missile and released at a specific altitude, speed, and with the flight path tailored to reaching its target without being powered. A small propulsion system could be added to speed arrival at the target and provide directional control.
In contrast, hypersonic cruise missiles (HCMs) are powered all the way to their targets, flying high altitudes but lower than those of HGVs and launched from a rocket or jet aircraft. Power is delivered by air-breathing scramjet engines. Scramjets have been in development since the 1950s and they’ve proven to be extremely difficult to perfect, with the most successful results produced only since the 2000s. The trajectories of both types of weapons are shown in Figure 1.
Figure 1: Hypersonic glide vehicles (also known as boost-glide vehicles) are typically launched from a ballistic missile and released at a specific altitude, speed, and with the flight path tailored to reaching its target without being powered. Hypersonic cruise missiles are powered all the way to their targets, flying high altitudes but lower than those of HGVs and launched from a rocket or jet aircraft.
RF technology is key to powering many advanced electronics applications in hypersonic missiles. However, designing a crucial RF interconnect system that will perform well and withstand the extraordinary environmental and technical conditions presented by hypersonic missiles requires unique, highly customized coaxial cable solutions to prevent failure.
For example, a hypersonic missile utilizes multiple antennas and sensors with phase-matched or time-matched cables. These elements must survive at speeds that can exceed Mach 5, at times topping 5,000 mph. At such speeds, the temperature on the surface and in the boundary layer of the missile may exceed 1,800° F (1000° C).
During its journey, hypersonic missile guidance will reach temperatures ranging from 200° C to as high as 1000° C. This creates a unique material challenge as extreme temperatures will melt the plastics and polymers typically used in coaxial cables.
High-performance dielectrics and phase-matched systems are essential to meet phase versus temperature requirements. A hypersonic missile will go through the top of the atmosphere, generating vast amounts of heat, like a space capsule during re-entry. As the cable moves from cold to very hot temperatures, the phase matching between cables needs to track.
Hence, phase is a crucial parameter for detection and measurement in RF systems that rely on high accuracy continuous transmission and reception of RF signals. RF signals must travel through coaxial cables at consistent speeds regardless of environmental factors. Temperature variations degrade the electrical match between coaxial cable assemblies. That small amount of degradation, known as phase tracking characteristic, can adversely affect system performance.
For example, the electronically steered antenna used in many RF applications employs an array of radiating elements to steer antenna beams rather than physically moving an antenna. Beam steering for transmission or reception is performed by adjusting the phase of the individual antenna elements in the array. High-frequency transmission lines feed each antenna array element. The accuracy of the signal phase presented to each array element depends on the phase accuracy and stability of the cable assemblies. Therefore, cable assemblies optimized for phase performance usually exhibit minimal changes in phase with temperature.
Modern missile systems also utilize extensive communications equipment packed within a highly confined space. This creates a demand for novel solutions that combine a small form factor with reduced weight and rugged construction to withstand the high impact and vibration conditions from deployment to target.
Polytetrafluoroethylene (PTFE) has traditionally been the dielectric material of choice for many high-frequency cables, as it provides excellent flexibility and low loss. However, at +19°C, PTFE exhibits a well-known deviation, commonly referred to as the “knee,” in its phase versus temperature characteristics due to a change in its crystalline state. This abrupt change in phase length at +19° C can generate inaccuracies in systems that use phase as a measurement parameter.
These inaccuracies, though slight, can lead to much larger, crucial issues; any variations in the electrical behavior of RF/microwave coaxial cable assemblies can introduce amplitude and phase variations that degrade the performance of a phased-array radar system overall.
Silicon Dioxide Coaxial Cables
Hypersonic missile systems cannot tolerate phase errors, so cable designers must consider other materials that do not present the same shortcomings as PTFE. Times Microwave Systems developed a proprietary silicon dioxide dielectric (SiO2) to address these unique challenges (Figure 2). Silicon dioxide is well known in the microelectronics industry for its excellent insulating properties.
Figure 2: Times Microwave Systems SiO2 cable, designed to meet the challenges of hypersonic missiles and other demanding spaceflight systems
The SiO2 construction starts with a solid oxygen-free copper center conductor, a silicon dioxide insulating dielectric, and a stainless steel jacket with copper cladding to act as the outer conductor. Low loss, high-velocity silicon dioxide dielectrics excel in extreme environments as they provide excellent phase stability and can perform at extreme temperatures ranging from just above absolute zero to 1000° C. In addition, compared to other cable types, SiO2 cables provide exceptionally low hysteresis, with phase and loss returning to the same values at a given temperature even after extreme excursions.
The metal and silicon dioxide dielectric construction make the cable resist radiation naturally, up to 100 Mrads. All connectors for Times’ SiO2 cable assemblies employ a crack-free, fired glass seal to provide the optimum microwave performance. The stainless steel jacket is welded to the connectors with laser beam technology to create a hermetic seal.
Between the silicon dioxide dielectric and the tight tolerances of each cable assembly, SiO2 has an EMI shielding of better than 110 dB. The 50 ohm cables are available with outer diameters of 0.090, 0.141, and 0.270 in. with cutoff frequencies of 64, 36, and 18.5 GHz, respectively.

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Frequency Matters Podcast: Hypersonic Weapons with Dave Slack
Frequency Matters Podcast: Hypersonic Weapons with Dave Slack
Summary
Gary Lerude of Microwave Journal recently spoke with Dave Slack, Engineering Director at Times Microwave Systems, on hypersonic weapons. Watch the complete video or read the session notes below.
Session Notes
Hypersonic weapons have been a hot topic in the news lately. Please give us some background on hypersonics and what all the buzz is about.
A really quick definition of hypersonic is that it describes any speed faster than five times the speed of sound (above Mach 5). The hypersonic weapon systems creating all the buzz today will go faster—about 10, 15, 20, or even 25 times the speed of sound.
Hypersonic technologies are not new; however, they have been around for 70 years or so since the end of World War II. Examples include Sputnik, the Apollo missions, SpaceX rockets, etc. What they all had in common is that they have a ballistic path, a parabolic arc set by the force of gravity and launch velocity. The path is very predictable, and it is easy to determine where the vehicle came from, where it’s going to land, etc., so it’s easy to defend against and countermeasure.
The difference today is that the new generation of hypersonic vehicles is steerable. This makes it challenging to determine precisely where it came from, which is a game changer. The weapon system that is getting the most attention right now is hypersonic glide vehicles. These are initially launched on a parabolic or ballistic arc but can drop down much lower in altitude mid-course and “glide” at a relatively low atmosphere at hypersonic speeds. As a result, they are much more challenging to detect.
Not only are these missiles traveling at hypersonic speeds, but they are also maneuverable. As a result, the time to react could be as little as two-three minutes compared to 45 minutes or an hour with other missile types, so they are very difficult to defend against. Additionally, there are hypersonic cruise missiles, powered vehicles with a scramjet or a supersonic ram jet. That is another game changer because it can travel at much lower altitudes at much longer ranges and is powered, so it’s not just gliding.
Given the physics associated with hypersonic speeds and the extreme environmental conditions, what kind of challenges or emerging technologies have hypersonics created?
The maneuverability factor is the primary issue when it comes to electronics. Every time the missile maneuvers, it loses energy, which is then dissipated as heat. This is in addition to the heat caused by the friction of slipping through the air stream. Dealing with that heat is one of the significant technical challenges.
Smart weapons are also precise and accurate, usually requiring someone on the ground to identify a target, communicate with the weapon, and guide it at hypersonic speeds. These vehicles are surrounded by a plasma envelope, which is why space vehicles lose communications for a few seconds on re-entry because the envelope shields them from communications. Penetrating the plasma envelope to communicate with the weapon and steer it creates another big technological hurdle. This drives the need to evaluate smaller, lighter options that can operate at higher temperatures.
RF microwave technology is used on hypersonic weapons in onboard systems for communication, as well as detection and countermeasures. I expect the RF microwave community will play an increasingly important role in countermeasures.
Do you have a sense of the market evolving over the next few years as research and development turn into actual fielded programs?
The armed services and government development agencies rely on industry to develop these weapons, components, and underlying technologies. As a result, a lot of investment will flood into this space because it is the department of defense’s number one development priority right now and will likely continue to be a top priority for at least the next ten years.
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Don’t let supply-chain disruptions knock your projects off schedule – navigate roadblocks and stay on track
Don’t let supply-chain disruptions knock your projects off schedule – navigate roadblocks and stay on track
Originally published in Military Embedded Systems
By David Kiesling
In today’s unusually challenging environment, companies may need to look for workarounds to stay on track regarding supply chain and delivery. Some electronics companies are learning the hard way that supply-chain resilience is a critical qualification for doing business, whether in their own or in their business partners’ and suppliers’ operations. These lessons will change the way organizations consider procurement and production decisions for the future.
Every business – including those that supply the military-electronics arena – is feeling the pain of supply-chain problems these days. Many, in fact, are finding it impossible to run efficiently, meet demand, and deliver on time when necessary parts and materials are stuck in limbo.
Survival of the fittest
The current tight supply-chain situation is having a painful impact on many companies, slowing production as parts, materials, and labor become scarce. Whether you are waiting on products or services like installation and repair, deadline slippage is beyond frustrating. The delays can kill your revenue, cause you to lose loyal customers and new business, and damage your business relationships.
Planning for the long term might sound a bit ambitious when the more immediate problem is that today’s orders are stalled, so let’s start by discussing survival strategies for the current logjam.
Workarounds you can implement now
Decide first if your current suppliers can meet your immediate needs. Can you wait? If delays are seriously impacting your business, consider all your options. Not all products or suppliers are equally prepared to operate through a supply-chain crisis like this. Those with the lowest incidence of backlogs right now either laid the groundwork for resilience before 2020, or they pivoted quickly to prioritize supply-chain agility as the going got tough. The most successful probably did both.
Look around for alternate suppliers if you need to. You can minimize delays by working with the companies that can support your short-term needs more quickly than your existing partners can accommodate.
If you’re lucky enough to be getting what you need, when you need it, from your existing suppliers – consider placing or confirming orders and inventories as early as you can. That way, you won’t get left behind or caught short.
The long game
These challenges will light the way for successful organizations to prioritize resilience to grow and prosper in the future. How can you be better prepared for tomorrow, next month, next year? Survive the present, of course; protect your relationships and reputation as best you can, using the mitigation tactics discussed above. While you’re at it, consider long-term changes that will better position your company for whatever lies ahead.
Find partners with multiple production facilities worldwide; they can often move your work to areas where bottlenecks are less severe so that changing global challenges don’t shut off your supply. Different regions of the world are feeling COVID-19 impacts and shipping snafus at different times, so redundant geographic capabilities can alleviate regional pressures.
For example: Over the past few years, Times Microwave Systems strategically managed growth, preparing for a situation such as this by opening new manufacturing and warehousing facilities in China, India, and Europe. Moving production closer to customers allowed for shorter delivery routes and created more options for mitigating shifting labor and supply-chain issues. When difficulties arose, it was possible to maintain a steady inventory and supply of the products and services customers relied on.
Decentralized manufacturing capabilities enabled uninterrupted production throughout the pandemic, building inventory needed to meet immediate demand. By continually increasing on-hand stock for standard materials across internal and distributor-serviced warehouses, companies that prepared this way are now better-suited to weather the volatility in raw material costs, thereby resulting in more stable pricing for customers.
Flexibility and versatility should also be considered in business and supplier relationships. A company that offers custom solutions can work with you to develop the most feasible systems at the time. You can thus avoid getting locked into a one-size-fits-all system design that depends upon one source, one material, or one standard product that could be in short supply when you actually need it.
Watch out for false promises
Make sure you are buying genuine products from a reputable company to ensure your system works as it should. Shortages tend to bring counterfeits, fakes, and clones out of the woodwork, as unscrupulous operators look for ways to cash in on a crisis. The performance of your customers’ products depends on reliable product sourcing. Customers that unwittingly buy inferior products sold under false pretenses often pay the price with dismal system performance.
Moving through and forward
Do whatever you have to do to get through this crisis. Be flexible. Build resilience for the future. Work with organizations that are working through the current issues with minimal disruptions. And adjust your approach to qualifying the companies you work with so that you’ll be ready for the next uncertainty.

Adding new high-frequency capabilities to military avionics applications
Adding new high-frequency capabilities to military avionics applications
By Ted Prema
Originally published in Military Embedded Systems
The high-frequency radio frequency (RF) interconnections within military avionics systems are essential components. They must perform repeatably and reliably and meet reduced size, weight, and power (SWaP) requirements. At the same time, the RF coaxial cables and connectors operating in these critical avionics applications have complex electrical, mechanical, and environmental requirements and must remain accessible for maintenance or troubleshooting.
Additionally, fitting these systems into very tight spaces can allow unwanted coupling between RF transmission lines such as coaxial cables. High-density, modular multiport interconnect systems can create a smaller, modular connector assembly. Such multiport connector systems integrate multiple coaxial connector contacts into a single housing for much higher interconnection density than individual coaxial connections.
Frequency requirements are rising
Today’s military avionics technologies, including intelligence, radar, collision avoidance, electronic guidance, navigation, electronic warfare, and communications, require higher frequencies to provide increased bandwidth for a growing number of complex subsystems. Military avionics systems that once operated at frequencies of 12-18 GHz are now extending into the millimeter-wave (mmWave) frequency range of 30 GHz and beyond.
High-frequency RF interconnects for military avionics systems must retain their predecessors’ lightweight and small form factors to fit the high-density requirements of modern airframes and avionics systems. Driven by reduced SWaP equipment requirements, avionics systems are being mounted within smaller airframes and equipment housings, requiring coaxial assemblies to maintain reliable electrical and mechanical interconnections in tight spaces and under the most severe operating conditions.
Such a compact modular multiport connector system provides smaller, lighter interconnections to support denser, more tightly packed avionics systems. By mating a single multiport connector rather than multiple separate coaxial cable assemblies, the single connector interface provided by multiport shells reduces installation time, can ease system maintenance and testing, and increase reliability.
Expand capabilities within existing infrastructure
Military avionics interconnect systems operate in harsh environments on a wide range of airframes, enduring high-shock and vibration; corrosive effects of fuels, hydraulic fluids, and other chemicals; vacuum-like conditions created by high altitudes; and wide temperature ranges. These military avionics systems must handle these challenging environmental conditions while packing greater functionality into smaller spaces. This requires new coaxial cables and connectors to deliver high signal integrity and reliability.
Critical considerations for RF interconnects for challenging avionics and airframe applications include:
- Lightweight: Weight reduction is critical to increasing fuel efficiency. Today’s frequency band requirements are also becoming more complex, creating the need for additional lightweight, small, high-precision RF solutions.
- High density: The increasing number of antennas in military avionics applications creates the need for more electronic boxes and their connections. Furthermore, new high-density solutions are required as frequencies increase and interconnect dimensions decrease to accommodate shorter wavelengths.
- Shock and vibration: When a connector attached to an antenna vibrates, as it will in flight, microphonic noise can impact the connection. This can cause interference in the signal transmission and errors for the RF system. Minimizing space between the cables and connectors is necessary for the interconnect system to survive the high vibration. Furthermore, this microphonic noise wears out the plating on the pins. Use of spring-loaded interfaces can all but eliminate this for both electrical and mechanical improvements.
- Temperature: Higher altitudes, speeds, and frequencies result in higher temperature requirements, making materials considerations more complex.
- Maintenance and access: Antennas mounted on the aircraft’s exterior are routinely damaged, and expedited repair of those antennas is essential. However, antennas are often difficult to access in many avionics systems, making maintenance and replacement very complicated and time-consuming.
Multiport shells such as the M8 multiport connection system are constructed from lightweight aluminum and have advanced reach/ROHS-compliant conductive platings tested to the most severe corrosion resistance requirements. (ROHS is a directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment.) The new contact designated M8M works up to 40 GHz and meets the needs of new high-frequency applications. The M8 multiport system has a a shielded structure to meet the electromagnetic interference and electromagnetic compatibility (EMI/EMC) requirements of densely packed military and civil avionics systems. The design also enables blind-mating interconnections. A spring-loaded design aims the parts for use in the harsh, high-vibration, environments typically found in military avionics applications. These parts are in service on a variety of U.S. and allied military aircraft from SIGINT/ELINT [signals intelligence/electronic intelligence] platforms to fast fighter jets.
Advanced military avionics electronics applications must accommodate extremely restricted space constraints and rising operating frequencies. A military avionics wireless system’s range that once operated between 12 and 18 GHz is now extending into the millimeter-wave (mmWave) frequency range of 30 GHz and beyond. High-frequency RF interconnects for military avionics systems must retain their predecessors’ light weight and small form factors to fit the high-density requirements of modern airframes and avionics systems.

Phase-Stable Cables and the Challenges of Space
Phase-Stable Cables and the Challenges of Space
Satellite communications are an indispensable part of global infrastructure, enabling real-time data transmission anywhere on earth and into space. As commercial industries increasingly work to advance and expand connectivity with powerful new 5G technology, space-based platforms and satellites will become even more critical.
The cables, connectors, and RF solutions deployed in space are integral components enabling industry to successfully move satellites, enable earthbound communications, and transmit information contributing to climate science, global security, communications relays between continents, high-speed Internet, and more. The enormity of global connection and data sharing needs is growing by the day—and the communication infrastructure’s performance is vital.
Therefore, designing a crucial interconnect system that will perform well and withstand the extraordinary environmental and technical conditions of space reliably and consistently over long periods is not like designing any interconnect. Cable assemblies used in spacecraft need to brave high shock and vibration, extreme temperatures, and intense radiation. In addition, satellites have limited space for equipment, so minimizing size and weight are also key goals. Cable assemblies must be designed to perform reliably while taking up the smallest footprint possible.
Two primary considerations for optimizing RF interconnect systems, selecting the right technologies, and accommodating the unique requirements of deployment in space include smaller footprints—lightweight, high-density connections, and intricate installations in very tight spaces—and phase stability in terms of temperature and bending/motion. The critical requirements are detailed further below.
Smaller Space Requirements
Equipment used to power space technology must be lightweight, and RF coaxial cable assemblies must be designed to perform reliably in the smallest possible footprint. The high-frequency cables required for space applications also have a shorter range, requiring a dense network of antennas. Additionally, minimizing space between the cables and connectors is necessary for the interconnect system to survive the high vibration and other harsh environmental conditions.
Technology providers are working on advanced designs that accommodate these extremely restricted space constraints and rising operating frequencies to produce spaceflight connectors that successfully operate up to the 70 GHz range. This requires new coaxial cable and connector designs to deliver high signal integrity and reliability in increasingly dense environments.
One example of innovation in this area is Times Microwave’s new PhaseTrack InstaBend 047 (PTIB-047) microwave assemblies, which provide a flexible preassembled design for interconnects between RF circuit cards, modules, and enclosure panels, enabling space-efficient implementation for higher frequency systems that also need phase stability.
The new PTIB-047 is a phase-stable microwave assembly designed for a range of frequencies from DC to 70 GHz. The cable utilizes Times Microwave Systems’ proprietary TF4 dielectric material for superior phase stability over temperature, eliminating the problematic non-linear phase performance of PTFE through 15 to 25ºC. PTIB-047 is ideal for in-the-box applications with space constraints, including space flight, thermal vacuum, microwave test, and many other commercial and military applications. The cable can be bent very closely behind the connector, minimizing footprint, saving space and simplifying cable routing. This also eliminates the need to protect the back of the connector.
Phase Stability
Tight phase control is crucial for optimizing system performance in technologies including 5G smart antennas. Two primary elements can affect a coaxial cable assembly’s phase tracking characteristic: electrical length and temperature. For example, phased array radars that have multiple antenna elements rely on coaxial cables having the same electrical lengths between the transmitter-receiver and antenna. This poses challenges on how to match the cables.
Transmission lines feed the arrays; beam accuracy depends on those cables’ phase relationships. Phase is also responsible for precision in some more time-sensitive satellite applications like GPS and radar. The phase must be accurately controlled in the components within those systems, and phase-stable cable assemblies are essential in today’s increasingly sophisticated electronics.
After that initial matching, the coaxial cables must also stay matched over varying temperatures. As temperatures change, coaxial cables do not precisely track together; the phase match degrades just slightly. That small amount of degradation can adversely affect system performance. Therefore, some cable assemblies must be optimized to minimize phase change over temperature.
The concept of phase starts with the fact that a microwave signal propagates in the form of a sine wave. For every sine wave cycle, 360 deg. of electrical length will accumulate. Millions or billions of cycles per second will accumulate in the higher frequency range of 5G applications. The wavelengths are very short, so maintaining phase accuracy across a cable length becomes exponentially more challenging as frequency increases.
Frequency, time delay, and physical properties like length, dielectric constant, and propagation velocity affect electrical length. Coaxial cables contain a consistent dielectric material throughout the length of the cable and hence have a constant velocity factor. Even though the material is consistent, environmental factors can alter the electrical properties of the cables, including temperature fluctuations, flexure, handling, twisting, pulling, and crushing that can happen to a cable during installation and maintenance.
A cable assembly also gets electrically longer as it gets colder and shorter as it gets warmer. Electrical length is proportional to physical length. Metals expand as they get warmer and contract as they get colder, but as that happens the dielectric constant expands and contracts and its density changes, altering the velocity. The dielectric effects of the plastic offset and dominate the metal effects.
RF coaxial cables often use PTFE dielectric because it can operate across a broad temperature range of 50º C to 150º C) and it has a low dielectric loss. The challenge with PTFE is that the material goes through a phase transition around room temperature, causing the phase length to vary non-linearly with temperature and introducing significant hysteresis as the temperatures vary up and down. Controlling phased array antennas with PTFE-based cables is challenging in varying temperature environments. Times has experience designing cable assemblies to minimize temperature effects on phase through the use of special materials, such as cables made from silicon dioxide and TF4 and TF5 proprietary foam polyethylene blended dielectrics.
The ultimate challenge for interconnect design engineers is finding flexible dielectric materials that meet the physical requirements and can also be phase stable across a broad temperature range. PhaseTrack InstaBend 047 incorporates this proprietary TF4 dielectric material for superior phase stability over temperature, making it another excellent option for small spaces that require phase stable solutions.
Conclusion
Searching for and qualifying an RF interconnect supplier for space applications can be lengthy and costly. Some suppliers offer standard qualifications and documentation for basic products to simplify this process. But nothing is standard or easy in space.
Custom designs, special testing and qualifications, and new product development for space applications require experience and commitment. “Standard” RF systems are not good enough in space. It is important to thoroughly evaluate the capabilities of an RF supplier to ensure a positive outcome.
In the design phase, consider the key considerations to be factored into any RF system that will operate in space: high-density equipment installation for minimal footprint; materials selection to withstand environmental challenges and optimize fit, weight, and durability; and phase stability for optimal signal transmission. Work with a reputable RF solutions provider who understands space’s unique requirements and can customize components to meet your application needs. A qualified provider will have experience designing custom solutions for defense, military, avionics and aerospace installations.
New RF Interconnect Solutions Power Mission-Critical 5G Networks
New RF Interconnect Solutions Power Mission-Critical 5G Networks
By Kevin Moyher
Originally Published in RadioResource Media Group
5G technologies are being rapidly deployed to deliver increased peak data speeds, ultra-low latency, enhanced reliability, enormous network capacity and increased availability. However, this requires a substantial expansion/upgrade to existing network infrastructure. For example, 5G networks must be densified to get the signal closer to users, which means more cell sites in more locations.
Small cells have emerged as the most practical means of attaining the densification needed to support the speed, coverage and latency requirements of 5G. These 5G small cell applications use multiple input multiple output (MIMO) antennas with multiple in/multiple out feeds, which substantially increases the number of RF ports. Additionally, unlike previous cellular technology generations, which focused on a specific frequency band, 5G deals with a much larger potential frequency range. For example, 4G frequency bands are typically below 3 GHz. 5G, on the other hand, can range from 450 MHz to 3.9 GHz and up to 20 – 56.2 GHz millimeter-wave (mmWave) bands for high-speed operations. 5G also encompasses unlicensed frequency bands, such as the 6 GHz band.
As a result, 5G antennas are shrinking in size as higher frequency bands are used to accommodate more extensive bandwidth requirements, which translates into more antennas and the corresponding RF cables and connectors needed to power them in a much smaller space. This equipment is also packed much closer than traditional telecom towers were years ago; at times, they are only about 100 yards apart. This requires new coaxial cables and connector solutions to deliver high signal integrity and reliability in increasingly dense environments.
The combination of smaller antennas with large numbers of cable connections also creates unique challenges related to installation, torquing, proper weather sealing and more. There are numerous variables to consider: Is it the right cable or the right port? Is that connector properly terminated to that cable? Is the coupling properly torqued down? Is the whole thing properly weather sealed? Are those cables properly captivated? Are they hooked up to the right connector and port? Are they flapping around in the wind? Are they protected from the sun, or if not, do they have the proper UV resistance?
We will discuss these concerns in more depth and provide a strategy for mitigating the challenges through the use of a bundled coaxial cable assembly solution designed for the ultra-demanding 5G small cell environment.
Bundled Cable Assemblies
A bundled cable solution can help create a flexible antenna jumper for applications requiring multiple runs, such as 5G. A spiral configuration of multiple flexible and ultra-flexible jumper cables can be created under a common polyurethane outer jacket to promote easy installation and improved operation. The individual coaxial cable runs are spun together in a way that easily flexes, essentially creating a bundle, which is then run through a large jacket extruder where a ripcord is placed.
This design enables four or five individual cables to be fed into the back of a single connector such as those based on the industry-standard MQ4/MQ5 design that encompasses a four-contact connector and a five-contact connector. The most common bundled cable constructions are built with inner cables that are one quarter of an inch and smaller and can be used on both non-low passive intermodulation (PIM) and low PIM interconnects. Constructions to address low PIM bundled harnesses include corrugated copper outer sheaths as well as ultra-flexible flat braid constructions.
Ensuring connectors are properly and securely tightened and eliminating any nonlinear or poor electrical contacts within the RF interconnect can also help reduce PIM issues. The MQ4 and MQ5 cluster connectors use an outer spring contact so that PIM performance is not tied to how well the tip of the outer contact is making to its mate. The connection between the male and female cluster connectors is sealed to IP67, as are the connector bodies and the transition from the cluster connector to the bundled cable. The solution is also keyed, eliminating the possibility of hooking up the wrong cable to the wrong port as the cables can only be hooked up a certain way; no torque wrenches, know-how or special technique required.
Using the four- or five-conductor solution eliminates the need to create individual weather seals, resulting in tremendous labor savings. Furthermore, it reduces the need to worry about coupling torque. This is critical because all it takes is an error on just one weather seal to create a point of ingress for water that could create a multitude of problems and even potentially shut the system down.
As a result, bundled solutions are optimal for high-density challenges as they permit installation in tight spaces; instead of connecting multiple threaded connectors, just one will do the job. They are faster and easier to install and maintain and provide one firm, reliable connection to support consistent high performance. An example of this type of solution is the TMQ4 and TMQ5 bundled cable assemblies from Times Microwave Systems.
The bundled coaxial cable assembly solution detailed above looks better in terms of appearance and cuts a lot of labor cost, and offers a more rugged solution with better UV resistance and weatherproofing. This helps support the densification needed for the speed, coverage, high frequency and latency requirements of 5G.
When it comes to selecting the right high-density RF cables and connectors, it is best to work with a partner whose engineers can identify the application’s unique needs and design an optimized solution that is ultimately easier to use, creating better electrical, mechanical and environmental performance. Look for a supplier with a long history of building quality cable and connectors, along with the skill, processes, techniques and materials to bring custom solutions for specific application needs to life.
New Multiport Contacts Add High-Frequency Capabilities to UAS Applications
New Multiport Contacts Add High-Frequency Capabilities to UAS Applications
By Times Microwave Systems
Originally published in Unmanned Systems Technology
Today’s unmanned aerial technologies, including intelligence, radar, collision avoidance, electronic guidance, navigation, electronic warfare, and communications, require higher frequencies to provide increased bandwidth for a growing number of complex subsystems. For example, the RF systems in unmanned aerial environments that once operated at frequencies of 12-18 GHz are now extending into the millimeter-wave (mmWave) frequency range of 30 GHz and beyond. As a result, system manufacturers are creating advanced new system designs to meet these evolving needs while accommodating extremely restricted space constraints.
The high-frequency RF interconnections within those systems are essential components—they must perform repeatedly and reliably and meet reduced size, weight, and power (SWaP) requirements. At the same time, the RF coaxial cables and connectors operating in unmanned aerial applications have complex mechanical, electrical, and environmental needs and must remain accessible for maintenance or troubleshooting.
The Multiport Shell Solution
SWaP equipment requirements require coaxial assemblies to maintain reliable electrical and mechanical interconnections in tight spaces and under the most severe operating conditions. However, fitting these complex systems into tight spaces can allow unwanted coupling between RF transmission lines such as coaxial cables.
High-density, modular multiport interconnect systems solve this problem by creating a smaller connector assembly with a higher interconnection density than individual coaxial connections due to integrating multiple coaxial connector contacts into a single housing. By mating a single multiport connector rather than numerous separate coaxial cable assemblies, the single connector interface provided by multiport shells reduces installation time, can ease system maintenance and testing, and increase reliability.
Solutions such as the M8 multiport connection system from Times Microwave Systems are constructed from lightweight aluminum and have advanced Reach/ROHS compliant conductive platings tested to the most severe corrosion resistance requirements. The M8 multiport system features a well-shielded structure to meet the EMI/EMC requirements of densely packed military and civil avionics systems and a design that allows for blind-mating interconnections for ease of installation. They are spring-loaded with sufficient force to ensure full mating engagement under severe vibration.
As the leader in multiport and mini-multiport shells and high-density solutions, Times Microwave Systems has also worked closely with prime contractors to develop plating materials with excellent salt fog resistance (2,000 hours) and Sulfer Dioxide resistance (668 Hours). This plating type is used on the latest, cutting-edge airframes as it is intended for use in harsh airborne and maritime environments requiring shell-to shell-conductivity.
New Contacts Provide Expanded Capabilities Within Existing Infrastructure
Unmanned aerial interconnect systems operate in harsh environments on a wide range of airframes, enduring high-shock and vibration; corrosive effects of hydraulic fluids, fuels, and other chemicals; high altitude conditions; and wide temperature ranges. These unmanned aerial systems must handle these challenging environmental conditions while packing greater functionality into smaller spaces. This requires new connector solutions to deliver high signal integrity and reliability.
The new M8M contact from Times Microwave Systems, based on time-tested multiport connector designs, is ideal for this environment. It was created for high-performance and easily survives harsh environments where high vibration, shock, temperature, and humidity can cause cable and system performance degradation.
The M8M contact is an addition to the Times Microwave Systems trusted high-performance M8 family of multiport interconnects, including the original M8 (18.5 GHz) and M8E contact (23 GHz) and lightweight, low insertion force V8 (18.5 GHz) contact. The new M8M contact works up to 40 GHz to meet the needs of high-frequency applications while using existing multiport shell infrastructure already in place. It is compatible with all M8 shells, and its unique construction makes the M8M contact excellent for use in the high vibration, harsh environments typically found in unmanned aerial applications.
The M8 family of multiport interconnect solutions has been the go-to system for many platforms worldwide throughout its more than 30-year history. Many tens of thousands of these parts are in service on a wide variety of US and allied military aircraft and have logged hundreds of thousands of flight hours. Times Microwave System also has fiber optic and octo contacts to fit into the same shells if multifamily interconnects are needed.
Conclusion
New RF interconnects for unmanned aerial systems must meet higher frequency requirements while retaining their predecessors’ lightweight and small form factors to meet the high-density needs of modern airframes and avionics systems. High-density modular multiport interconnect systems integrate multiple coaxial connector contacts into a single housing to create a higher interconnection density than possible with standard coaxial connectors. Building on the legacy of the trusted, proprietary Times Microwave M8 design, the M8M contact is an example of innovation that brings 40 GHz capability to multiport interconnect systems—using existing shell infrastructure already in place to maximize current investments.

Cables Keep Radar Antennas Tracking
Cables Keep Radar Antennas Tracking
Originally Published in Microwave Product Digest

Rapidly Advancing Technologies Create New Challenges for RF Test and Measurement
Rapidly Advancing Technologies Create New Challenges for RF Test and Measurement
Originally Published in Microwave Product Digest

Powering high-performance, ultrareliable RF systems in military electronics
Powering high-performance, ultrareliable RF systems in military electronics
By Ted Prema
Originally published in Military Embedded Systems
Radio frequency (RF) systems are used to power vital military electronics applications such as intelligence, surveillance, and reconnaissance (ISR) systems; communications systems; and electronic warfare (EW) suites. These systems must be extremely reliable and continually offer high performance – in very demanding, confined, and variable environments on the ground, in the air, and at sea. Each of these applications has unique requirements, driving development of custom RF interconnect solutions to address specific challenges. While safety comes first in the design of any of these complex military RF systems, performance must also be flawless.
For example, EW systems perform numerous mission-critical functions, including defense against attacks and providing enhanced situational awareness. These systems use RF signals to locate and identify potential threats, landscape features, and more, and include ground-based radar, antimissile defense, guidance systems, and similar applications. Each of these applications depends entirely on continuous real-time transmission of data with high accuracy.
Since these systems often operate under severe environmental conditions, two of the most important considerations in choosing optimal RF interconnect solutions include the use of low-smoke, zero-halogen cable and connectors and the use of assemblies optimized for high phase stability even at high temperature.
Optimizing for phase stability even at temperature
Fires are one of the most serious dangers in confined spaces such as in military aircraft, tanks, ships, and submarines. Fire can quickly fill an area with smoke, obscure visibility, and drastically impede safe evacuation. Toxic gases and the lack of breathable air add to the danger.
If a fire occurs in this type of confined space, it is crucial that the wiring and cables powering the RF systems do not give off toxic or optically dense gases when subjected to the high temperatures of the fire. Low-smoke, zero-halogen cable assemblies are therefore essential for passenger safety in spaces where air exchange is minimal. This is especially true in areas where densely packed cables are installed in proximity to humans or sensitive electronic equipment, which is why military users were one of the first adopters of low-smoke, zero-halogen (LSZH) standards.
The RF systems that perform critical operations in these environments must be designed to work as safely as possible within the application constraints. Under fire, a low-smoke cable (also known as limited-smoke cable) emits less optically dense smoke at a slower rate than a standard cable, enabling occupants to exit the hazardous area and protecting the safety of firefighting operations.
Halogens like chlorine, fluorine, and bromine are often used as effective fire retardants in wire and cables, enabling a cable to pass an industry flame test. However, halogens emit toxic gases when burning, so zero-halogen cables are another important requirement for military electronics systems. Halogen-free materials also produce clearer, whiter smoke for better visibility and do not emit halogen’s toxic off-gases.
Environmental challenges and phase stability
Phase is a key parameter for detection and measurement in many military RF systems such as radar, missile defense, EW, and many other systems that rely on continuous transmission and reception of RF signals with high accuracy and consistent speeds, regardless of temperature. The phase behavior of coaxial cable assemblies can adversely affect system performance when phase tracking is required and, as a result, phase must be extremely stable in the components within those RF systems.
For example, the electronically steered antennas used in many military RF applications use antennas with an array of radiating elements to steer antenna beams rather than physically moving an antenna. Beam-steering for transmission or reception is performed by adjusting the phase of the individual antenna elements in the array. The antenna array elements are each fed by high-frequency transmission lines; the accuracy of the signal phase presented to each array element depends on the phase accuracy and stability of the cable assemblies.
Military electronics systems are exposed to extreme and highly variable environmental conditions, such as corrosive salt spray in the ocean or high temperatures in the desert. For effective performance, the RF signals within those systems should travel through any coaxial cables with minimal delays and loss regardless of these environmental factors. As coaxial cables are subjected to cold and hot temperature extremes, their phase characteristics change as a function of temperature, with changes in the phase tracking or matching between cables. Even a small phase-tracking error between cables used in a phase-critical application, such as for a phased-array antenna, can adversely affect antenna performance.
Times Microwave offers PhaseTrack Low Smoke (PTLS) cable assemblies designed to meet the low-smoke, zero-halogen, and phase stability requirements of high-performance military electronics applications. The coaxial cable features a proprietary foam polyethylene blended dielectric called TF5. This innovative material provides exceptional phase stability with temperature performance to +85 °C and does not suffer the abrupt shift in phase that occurs with solid or tape-wrapped PTFE [polytetrafluoroethylene]-based coaxial cables. It eliminates the phenomenon known as the PTFE knee, in which the PTFE (also known as Teflon) undergoes a structural transition at approximately 18 °C that actually alters the dielectric constant of the material and substantially changes the delay of the transmitted signal. This nonlinear phenomenon is a property of the molecular structure of the PTFE material and cannot be eliminated regardless of advancements in dielectric manufacturing technology.
Offered as a complete assembly, the PTLS family of products are available in cable diameters from 0.2 to 0.6 inches, address all frequencies ranging from HF through K-band, and include an optimized version for minimum loss at Ku-band frequencies. The cables use a proven low-/zero-smoke, zero-halogen jacket.
To meet the demands of a variety of systems, these assemblies can also be supplied with any type of industry-standard RF connector or contact interface and be terminated with low-passive-intermodulation (low-PIM) 7-16, 4.3-10, or Type N designs and tested to an assured maximum PIM level -160 dBc.
New Connector Design Addresses Significant SMP Shortcomings
New Connector Design Addresses Significant SMP Shortcomings
Originally Published in Connector Supplier

RF cables and connectors for avionics balance size, materials
RF cables and connectors for avionics balance size, materials
By David Kiesling
Originally published in Military Embedded Systems
Today’s complex frequency-band requirements – including 5G, new and upgraded satellite communications (SATCOM) systems, instrument flight procedure (IFP) systems using Bluetooth, and more – are creating the need for additional lightweight, small, high-precision radio frequency (RF) solutions. These systems operate at frequencies up to 90 GHz in some cases. The avionics industry needs low-loss, high-temperature, high-flexibility cable for navigation, collision avoidance, and communication systems in applications such as GPS, Automatic Dependent Surveillance-Broadcast (ADS-B), SATCOM, and air-to-ground comms.
Avionics applications also have limited space, as they accommodate more application needs throughout the vehicle. As frequencies increase and interconnect dimensions decrease to accommodate the smaller wavelengths, semi-rigid solutions have traditionally been used for these applications. However, these assemblies in very small sizes become fragile, making installation difficult and troubleshooting impossible.
Use of highly flexible, high-performance cable can be used in densely packed in-the-box applications; such flexible assemblies can be bent around tight corners and very closely behind the connector to minimize footprint, save space, and simplify cable routing in tight spaces. The flexible cable eliminates the need to protect the back of the connector and simplifies maintenance.
In flight, extraordinarily high vibration puts stress on the board hardware. Minimizing space between the cables and connectors is necessary for the interconnect system to survive the high vibration.
Taking a cue from commercial air innovations
Urban air mobility (UAM) is a concept for a safe and efficient aviation transportation system that will use highly automated aircraft to operate and transport passengers or cargo at lower altitudes within urban and suburban areas. Most UAM vehicles will operate below 10,000 feet, with battery power limiting their altitude and endurance. As the technology evolves, the density of UAMs in motion will increase, and in a scenario called “swarming,” their ADS systems will need to be in constant communication to avoid collisions. These systems are largely dependent upon antennas and high-frequency transceivers to enable the sensors to talk to each other, so a low-loss, reliable, low-weight cable is critical for reliable communications.
Further developments include advanced air mobility (AAM) solutions, which build upon the UAM concept with applications that will operate beyond urban environments, ranging from delivery drones to electric vertical takeoff and landing (eVTOL) applications. Like electric vehicles, eVTOL controls run on onboard electric power, and batteries are heavy, so weight is a substantial consideration. As a result, these technologies require advanced solutions to meet new requirements while adhering to the size and weight principles that have governed their predecessors for decades.
Avionics for UAVs
Another rapidly growing area of avionics are those for unmanned aerial vehicles (UAVs). Some UAVs are fairly simple and use a single data link, which requires a relatively simple RF interconnect solution. However, as hypersonics are introduced, some of these UAVs are as much as Mach 5, which adds high-temperature requirements into the mix. The higher the altitude, the higher the speed, the higher the frequency, the more complex the problem from a materials point of view. These issues can be addressed with dielectrics; moreover, there is the possibility of using quartz materials as dielectrics for hypersonic applications.
Ultimately, whoever is designing the structure needs to understand the environment, the UAV’s altitude requirements, what sort of longevity is required, how often maintenance is allowed, and what kind of test environment is available. For example, will the UAV carry electronic warfare (EW) systems or electronic intelligence systems, or is the payload purely data links and video?
The right interconnect
A key consideration for avionics RF interconnections is the dielectric and how it behaves in that environment as it reaches a state of equilibrium with the surrounding environment. For example, an aircraft on the ground is fully loaded with air, while at flight altitude, more of a vacuum environment is created, with outgassing conditions for dielectric and other electronic materials. When the aircraft returns to the ground, the cable is fundamentally a vacuum. Any fluids or gases surrounding it will be absorbed by the dielectric, and they will recondense within it. At that point, the dielectric acts like a sponge: The only way to remove contaminants is to bake it. This is obviously not feasible inside an aircraft, so vapor sealing is also critical for high-end, high-performance, high-altitude applications.
So many factors must be considered in the design of the right RF interconnect solution. For example, polyethylene improves fire retardancy and flame resistance; it’s a really good cabling option for outdoor environments or for indoor environments with a fire-retardant, UL-listed jacket. A caveat: Polyurethanes can be significantly more flexible, but they cannot be used in a manned environment.
On the airframe side, PTFE (synthetic fluoropolymer) dielectric cables that tolerate high temperatures are typically used and can be combined with a higher-than-standard PTMP (polyester plastic) tape wrap that is very low loss. This type of solution can be used all the way up to 50 gigahertz or more. At the high end of the temperature spectrum, some silicon dioxide cables that are rated for up to 800 °C or more.
Connector optimization
The ultimate goal is to optimize connectors for mechanical, environmental, and electrical performance, and make it very easy to install. A number of aluminum and plastic connectors are available to keep it lightweight.
Development work is being done on plastics, including threaded connectors, snap-line connectors, bayonet-style connectors and more, with materials like Delrin. Additional research and development is underway on an ultralight solution, including a modular connector solution with a plastic coupling and tooling solutions. This approach would help with maintenance, enabling users to fix problems directly in the field.
Tooling can ease assembly
When there is a need to install the RF interconnect solution aftermarket or perform maintenance work in the field, tooling is available that eliminates the need to use razor blades in the field, making on-site assembly safer and easier in what could be a contested area. This approach from companies like Times Microwave Systems enables everyone to use the same tool on the cable for the same application as opposed to the alternative, multiple technicians using different types of tooling and techniques.
Times Microwave Systems offers InstaBend (IB) 047, a compact, phase stable, highly flexible, micro coaxial cable. Originally designed for space flight applications, this high-performance cable easily accommodates densely packed in-the-box applications. For more information, visit www.timesmicrowave.com.
Making Connections in Ruggedized UAVs
Making Connections in Ruggedized UAVs
By Dave Murray
Originally Published in Microwaves&RF
Military unmanned aerial vehicles (UAVs) are growing in numbers and complexity, taking on more advanced payloads with multiple sensors. Modern battlefield UAVs do everything that human-piloted air vehicles and their avionics systems once did, including electronic warfare (EW), signal intelligence (SIGINT), and surveillance, often flying at high altitudes and high speeds. Many military UAVs are designed with modular configurations to install different subsystems for each mission to optimize results.
Whether in standard or modular formats, military UAVs rely strongly on their RF/microwave interconnections to keep all systems linked, including from the UAV to the ground through demanding operating conditions. Specifying RF connectors, cables, and cable assemblies for military UAVs, especially as they increase their use of mmWave frequencies, requires an intelligent balance of many factors to keep all systems connected under all conditions.
Military UAVs vary in size and complexity according to application and mission, with larger, fixed-wing vehicles flying at higher speeds and altitudes compared to smaller, fixed- and rotary-wing vehicles used at lower altitudes in commercial and industrial applications. One of the better-known high-altitude UAVs, the RQ-4 Global Hawk, has flown at altitudes of 60,000 ft. and higher.
SWaP Considerations for UAV Components
Military requirements for size, weight, and power (SWaP) offer excellent guidance for component selection in UAVs because component weight and power consumption translate to a UAV’s operating range. In addition, components such as cables and connectors must fit into tight spaces and still be accessible for maintenance and measurement purposes.
UAVs contain many electronic parts and subsystems that must be interconnected, such as antennas, data recorders, radars, receivers, and transmitters. The cables and connectors provide the pathways for routing data, signals, and power throughout these subsystems. Any interruption in the pathways can be mission-critical, even fatal.
In general, space for components and payload in a UAV is limited, whether for military, commercial, or industrial use. The cables, connectors, and cable assemblies that provide interconnections within a UAV must meet tight space requirements while maintaining high performance and reliability. These interconnections have to satisfy challenging mechanical and electrical requirements within a UAV capable of enduring severe environmental conditions.
Choosing Cables and Interconnects: Where to Begin?
A practical starting point for sorting through coaxial cable interconnects is determining if they will even fit within the airframe. Smaller cables may fit where space is limited, adding little to the total weight of the UAV, but they may lack the performance to meet the electrical requirements of its electronic systems, so mechanical and electrical needs must be balanced.
Ideally, once installed, coaxial interconnections can be readily accessed for testing and maintenance purposes. UAVs with modular sensor systems will require access to interconnections for different modules used within the airframe.
Cable selection requires a balance of the mechanical, electrical, and environmental requirements for a UAV’s systems. Maximum cable diameter and weight are practical starting points when sorting through available cable solutions. The coaxial cable should exhibit low loss across a frequency range of interest, which will depend on the length and diameter of the cable.
The cable’s insertion loss and return loss (VSWR) also will be affected by the choice of connectors and how well the cable assembly and connectors are constructed. Low loss is particularly important for cable assemblies used at higher frequencies since signal power is limited at mmWave frequencies.
In addition to cable diameter and weight, the flexibility of a coaxial cable assembly is essential when determining whether a particular assembly can fit the needs of a UAV’s interconnections. Interconnect flexibility can be gauged in terms of its minimum bend radius, which is a function of a cable’s construction. Minimum bend radius effectively defines the space required for the smallest change in a cable’s direction.
Weathering High-Stress Conditions
High-frequency interconnect cable assemblies for military UAVs face severe conditions while in flight due to changing weather and stresses caused by high-speed operation. Some UAVs developed for high-altitude operation include hypersonic capabilities with speeds reaching Mach 5 and above. These speeds result in high-temperature environments for the UAV’s electronic components and systems, which must operate reliably at these higher temperatures.
Because the interconnections are such critical components, cables and connectors for military-grade UAVs are designed for operating temperatures as high as +300°C and total operating temperature ranges as wide as −65 to +300°C. Even the 300°C limit is being challenged; thus, Times Microwave Systems (TMS) has been asked to develop materials for its cables and connectors to handle these new challenges.
RF/microwave interconnections in military UAVs, especially those with phased-array antennas, require high phase stability with temperature. Phase-matched cable assemblies are typically used in antenna systems where phase is used as a beamforming and tuning parameter and in multiple-input/multiple-output (MIMO) antennas that combine the contributions of multiple antennas to send and receive high-frequency signals, often with wide modulation bandwidths.
High-altitude (typically 50,000 ft. or more above sea level) UAVs often operate in conditions that expose their components to near-vacuum environments, resulting in moisture-absorption problems when it returns to sea level. This “water in the cable” affects the interconnect amplitude and phase characteristics of the cable’s conductive metals and dielectric insulators and may result in significant degradation and failure of an electronic systems. As a preventative measure, coaxial cables designed for military UAVs, especially those for high-altitude operation, usually include some form of environmental seal against the effects of vacuum-like environments.
Adding Connectors
The mechanical, electrical, and environmental performance levels achieved by a UAV’s coaxial cables also must include its connectors as they contribute to the SWaP levels. Connectors are typically designed for ease of installation and minimal mechanical and electrical performance degradation. For UAV applications, the high-performance levels must be maintained at high shock and vibration levels.
The quality of a coaxial connector’s machined components, as well as performance and reliability, are impacted by how well the connector is attached to the cable and the effectiveness of its locking mechanism in a mated pair of connectors. Connectors can be soldered or crimped to a cable, with soldering the more labor-intensive approach but providing a robust mechanical attachment with little performance degradation over time. An effective plated finish on a coaxial connector also can contribute to reliable and consistent long-term performance.
Due to the modular architecture of some UAVs, some coaxial connectors must endure many mate-demate cycles for changing of function modules within the UAV. In such cases, a connector’s mate-demate lifetime needs to be evaluated along with its mechanical, electrical, and environmental performance parameters to achieve the best fit within a particular UAV. Oftentimes, high-frequency, high-performance blind-mate connectors are used in UAVs for this purpose.
Seeking Solutions
Practical UAV interconnection solutions are typically available as cables or cable assemblies constructed according to precise lengths and designated connectors. For example, TMS’s MILTECH flexible cable assemblies (Fig. 2) from Times Microwave Systems feature excellent shock and vibration resistance and good phase stability over a wide operating temperature range (−65 to +200°C). They’re manufactured to applicable military standards with tight cable/connector interface control to achieve the hermetic seal needed for high-altitude flight.
The cables are constructed with polytetrafluoroethylene (PTFE) dielectric, a solid silver-plated copper center conductor, and a silver-plated copper shield for protection from electromagnetic interference (EMI). Furthermore, they’re factory-terminated with a variety of coaxial connectors.
To meet the tight space requirements of different UAV systems, MILTECH cables come in various sizes/weights, including 0.130-in. (3.30-mm) diameter cables with 0.650-in. minimum bend radius and 0.175-in. (4.45-mm) diameter cables with 0.875-in. minimum bend radius. The smaller-diameter cables can be terminated with 2.4- or 2.9-mm connectors for use at mmWave frequencies. The cables feature high moisture resistance and vibration resistance according to MIL-STD-202 requirements and high shock resistance per MIL-E-5272 requirements.
For tight UAV fits requiring cables bent close to the connector, TMS’s INSTABEND 047 cable assemblies (Fig. 3) provide low-loss propagation of signals up to 62 GHz in the tightest spaces. To ensure high-quality attachment of connectors to cable, they’re only available as complete assemblies.
An INSTABEND 047 cable assembly with an outside diameter of 0.10 in. (2.67 mm) provides a minimum bend radius of 0.3 in. (6.4 mm). Light in weight for UAVs, these cable assemblies weigh only 0.01 lb./ft. (0.02 kg/m) and are available with several different connectors depending on frequency range. They handle temperatures from −60 to +125°C, are shielded to −90 dBc, and rated for voltages to 100 V.
When phase must be tightly controlled, PhaseTrack cables and cable assemblies developed by Times Microwave Systems are well-suited for that parameter, coming in a variety of diameters with different connectors. A 0.108-in. diameter cable (Fig. 4) features a cutoff frequency of 80 GHz and a minimum bend radius of 0.550 in. The cable is constructed with proprietary TF4 dielectric and doesn’t suffer the phase variations with temperature common to cables with PTFE dielectric.
PhaseTrack cable assemblies fit ground, sea, airborne, and space platforms. They’re available in many versions, including a silicon-dioxide (SiO2) dielectric for applications with temperatures exceeding +1000°C.
Rugged Connectors
Maintaining connections under high shock and vibration levels common to a UAV while being easy to mate requires a coaxial connector with a simple but effective locking mechanism. The TLMP push-on locking connector from Times Microwave Systems (Fig. 5) was designed with the small form factor of the popular SMP push-on connector but with improved mechanical, electrical, and environmental performance.
The TLMP connector, which is usable to 60 GHz, has a unique mechanical design that supports high-pulsed-power, high-voltage applications. Its latching mechanism achieves improved mating retention compared to an SMP connector even in the high shock and vibration environments of military UAVs. The connector’s slots are entirely covered with its mating part for improved EMI and EMC performance compared to an SMP connector. Connections must maintain high EMI and low levels of signal leakage to prevent an adversary from identifying a military drone in flight.
For UAV interconnect applications that don’t require a hermetic seal or enhanced phase stability, Times Microwave Systems’ LMR and TCA cables and cable assemblies can be practical options. LMR cable assemblies provide flexibility to enable tight fits while LMR LW cables feature an aluminum braid shield for effective shielding in low-weight cable assemblies usable through 8 GHz. TCA cables and connectors have long served commercial avionics systems as flexible interconnect solutions, offering a combination of light weight and durability through 5 GHz and higher.
High-Density RF Interconnect Systems
High-Density RF Solutions
Technology providers are creating advanced new wireless system designs to accommodate extremely restricted space constraints and rising operating frequencies. These solutions need new coaxial cables and connectors to deliver high signal integrity and reliability in increasingly dense environments. Industries requiring high-density RF interconnect systems include 5G, space, and avionics.
5G
Antenna densification is required to deliver increased peak data speeds, ultra-low latency, enhanced reliability, enormous network capacity, and increased availability for 5G. Its specifications are based on MIMO antennas, which are shrinking in size as higher frequency bands are used to accommodate larger bandwidth requirements. This translates into more antennas in a smaller space.
Small cells are a great example of this as they are packed much closer than traditional macro-telecom towers, often only 100 yards or so apart. Demand for high-density cabling solutions to accommodate the necessary connections in smaller, more compact installations will continue to grow. This includes high-density interconnect solutions, such as multiport connectors and coaxial cable bundles.
Bundled coaxial cables use a coaxial feeder cable bundled under a common outer jacket. This innovative design acts as the perfect flexible antenna jumper for applications requiring multiple runs, such as 5G small cells located on towers or building-top sites.
The increasing demand for high coverage antennas has also led to substantial growth in the number of ports on antennas and RF devices. Hooking up the right cables to the correct ports, weather sealing, and torqueing are all concerns in this scenario. Multiport connectors can be used in this instance to reduce the number of connections.
This type of “RF cluster connector” incorporates multiple RF ports in one connector, enabling antennas to provide more ports without the need to increase dimensions. There are standardized designs that encompass a four-contact connector and a five-contact connector including our TMQ4 and TMQ5 multiport connectors. These can significantly reduce the number of cables that have to be hooked up, saving a lot of labor and creating a more rugged solution. They also make the assembly more weatherproof and UV resistant and reduce the need to worry about coupling torque.
Space
Equipment used to power space technology must be lightweight, small, reliable, and resistant to high-shock and vibration, radiation, and harsh/extreme temperatures. RF coaxial cable assemblies must be designed to perform reliably in the smallest possible footprint. The high-frequency cables required for space applications also have a shorter range, requiring a dense network of antennas.
Our new InstaBend™ high-performance microwave assemblies provide a flexible preassembled design for interconnects between RF circuit cards, modules, and enclosure panels, enabling space-efficient implementation for higher frequencies. The cable can be bent around tight corners and very closely behind the connector, minimizing footprint, saving room, and simplifying cable routing in tight spaces.

Aviation
Avionics applications also have limited space as they accommodate more application needs throughout the vehicle. In the past, it may have been common to have 12 antennas on a commercial airframe, but there are now about 50 or more. The increasing number of antennas in aircraft environments also creates the need for more electronic boxes and their connections.
Additionally, minimizing space between the cables and connectors is necessary for the interconnect system to survive the high vibration. InstaBend is also a great fit here. Our Instabend assemblies withstand high vibration and other harsh environmental conditions, ensuring a consistent, long-lasting connection.
Additionally, a new generation of locking miniature push-on connectors, such as our TLMP™, is specifically designed to address the shortcomings of SMP-style connectors. The TLMP connector retains the small form factor of the SMP for highly dense environments but adds improved environmental, shielding, and power capabilities, with a frequency range from DC to 60 GHz. A positive locking feature with visible green (locked) and red (unlocked) color coding prevents de-mating under vibration and shock.

Key Considerations for Coaxial Cables in Space
Key Considerations for Coaxial Cables in Space
Phase Stability
For phase-sensitive systems, compensating for the knee multiple times per orbit as the spacecraft moves through its operating temperature range is challenging and limits overall system performance. Other dielectrics such as Times Microwave’s TF4™ dielectric and Sio2™ silicon dioxide materials do not produce a similar non-linear change. In addition to controlling overall phase change vs. temperature, designers may need to characterize the hysteresis of the phase change across the operating temperature range. The silicon dioxide dielectric provides linear phase change with exceptional repeatability for applications requiring low hysteresis.
Return Loss
The second major environmental consideration for spaceflight applications is electrical performance over radiation exposure. Plastics such as PTFE and TF4 will degrade over time, increasing loss. For short-duration or risk-permissive missions, these long-term concerns may not be compelling. For long-duration, high-exposure, or high-reliability missions, using radiation-tolerant coaxial solutions such as the SiO2 line is better than shielding a plastic.
High Density
The high-frequency cables required for spaceflight applications have a shorter range, requiring a dense network of antennas.
Many different requirements may apply in terms of RF and microwave interconnects used with ground-based satellite dishes, such as high-frequency performance, low-attenuation needs, phase stability, and low-PIM performance. Our TCOM, MaxGain, and LMR products are designed to address these needs.
At the same time, technology providers are working on advanced designs that accommodate extremely restricted space constraints and producing spaceflight connectors that successfully operate up to 70 GHz. Our new InstaBend high-performance microwave assemblies provide a flexible preassembled design for interconnects between RF circuit cards, modules, and enclosure panels, enabling space-efficient implementation for higher frequencies.
The high-performance microwave assemblies are ideal for in-the-box applications because the cable can be bent very closely behind the connector. This minimizes footprint, saves room, and simplifies cable routing, eliminating the need to protect the back of the connector.
Materials
In addition to the issues of smaller cables tightly packed and connected, space applications require materials and constructions that withstand radiation, sandblast storms, extreme temperatures, and pressure variations. The latest materials technology and manufacturing processes are needed.
In the past, semi-rigid cables have been the standard cabling solution in space applications because their solid copper outer conductor protects the dielectric material inside. Today, special semi-rigid cable solutions based on silicon dioxide dielectrics are available. For example, our SiO2 cable assemblies are highly temperature and radiation resistant.
Some antennas fold into the satellite when not in use and unfold upon arrival at the satellite’s destination. There, the antennas will point to other satellites, get a position, and lock mechanically. Flexible cables are needed to work around the elbow that enables the antenna to fold and unfold.
Connectors
New styles of connector interfaces such as Times Microwave’s TLMP address the electrical and mechanical weaknesses of traditional high-frequency SMP/SMPM interfaces for high-vibration spaceflight applications. They visually indicate full engagement by exposing a green ring on the connector body when successfully mated.
Once routed correctly, it is also critical to ensure that the cable is appropriately mated to ensure effective RF performance. For threaded connectors, RF assembly suppliers should be able to provide recommended connector torque values. Designers should also consider multiport connectors that will mate multiple contacts simultaneously, reducing the opportunities for error.
Times Microwave Systems: The Ideal RF Interconnect Partner for Demanding Space Applications
Qualifications and Heritage
Our team has deep experience in space and other mission-critical industries such as military and defense.
Breadth of Products
Components deployed in space must meet many technical standards. There is, however, no standard for how to apply these materials to construct a consistently reliable RF solution. That is where our expertise and access to a full range of product options are needed. You can select the suitable material and choose from multiple cable constructions, various connector designs, and assembly techniques, all from the same supplier.
Dedicated Technical Experts
The complexity of space applications requires an effective partner who will work collaboratively to extend your design team. We help our partners understand the electrical and mechanical trade-offs particular to their unique space applications. Our technical team asks the right questions and listens to understand your unique needs, always considering innovative solutions.

Attenuation
Attenuation
Three properties define the attenuation of a coaxial cable: the conductivity of the conductors, the dielectric constant, and the diameter of the cable. In general, larger-diameter cables provide lower attenuation per unit length than comparable smaller-diameter cables, but this comes at the cost of increased mass and a wider minimum bend radius. Larger cables cannot be bent as tightly as smaller cables, and an overly tight bend will cause the cable to become oblong or, worse, to kink, causing an impedance mismatch and excessive return loss. A primary decision for designers is to balance the contribution of cable loss to their RF link budget with the mechanical considerations for system size and mass.
High-conductivity materials such as copper and silver provide low attenuation per unit length but are often heavy or expensive. Lighter-weight materials such as stainless steel and aluminum reduce overall mass but are poor conductors. Cable manufacturers frequently optimize their conductor designs by cladding or plating a lightweight, low-cost base metal with higher-conductivity copper or silver for the RF path.
A lower-loss dielectric generally will be lighter because it incorporates more air into the media. More air in the dielectric material lowers the effective dielectric constant of the total media and brings the loss closer to the ideal performance of a wave traveling in a vacuum.

Achieving High Density in Mission-Critical Circuits
Microwave Journal
Achieving High Density in Mission-Critical Circuits
By David Kiesling
Originally published in Microwave Journal
Technology providers are creating advanced new wireless system designs within restricted space constraints in avionics, 5G, space and many other industries. These applications rely on high density RF interconnections capable of high signal integrity and reliability in ever more miniature housings. There are many challenges to providing practical RF interconnections in such dense housing environments. Fortunately, innovations in RF interconnections have led to reliable, high performance solutions that can fit the tightest spaces available, even at the most difficult interconnection angles.
AVIONICS
Avionics applications have limited space as they accommodate more application needs throughout the airframe. In the past, it may have been common to have 12 antennas on an aircraft, but there are now 50—even hundreds in some cases—antennas serving advanced avionics systems. More antennas in aircraft environments leads to more signal paths and the need for more RF interconnect solutions to accommodate them.
5G
As more users rely on 5G services, more antennas will be needed to provide coverage, both at lower FR1 frequencies (under 6 GHz) and at higher FR2 mmWave frequencies. Antenna densification is required to deliver increased peak data speeds, ultra-low latency, enhanced reliability, enormous network capacity and increased availability for 5G. Many 5G networks employ MIMO antennas, which are shrinking in size as higher frequency bands are used to accommodate larger bandwidth requirements. This translates into more antennas in smaller spaces and more RF interconnections within those smaller spaces.
5G small cells, such as micro, pico and femto cells, are examples of the electronic densification within 5G networks as they are spaced much closer than traditional wireless macrocell towers, often only 100 yards apart. Demand for high density cabling solutions to accommodate the necessary
connections in smaller, more compact installations will continue to grow.
SPACE
Equipment used to support space technology must be lightweight, compact, reliable and capable of withstanding high levels of shock, vibration and radiation, as well as wide
temperature ranges. RF coaxial cable assemblies must be designed to perform reliably in the smallest possible footprint. The high frequency cables required for space applications
must support low loss communications, requiring a dense network of antennas.
HIGH DENSITY INNOVATIONS ABOUND
High density RF interconnection solutions have evolved from individual assemblies with multiple coaxial connectors to a single connection port. There are a wide variety of unique high density options suited to fit the specific needs of an industry/application, including multiport and mini-multiport connectors, bundled cable assemblies, locking miniature blind mate connectors and cable assemblies for densely packed in-the-box applications. Common requirements for these environments include ease of installation, high vibration (cannot come apart) and environmental seals.
MULTIPORT AND MINI-MULTIPORT CONNECTORS
Multiport and mini-multiport connector solutions are ideal for high density avionics environments, where space is at a premium, accessibility for maintenance is limited and performance is mission-critical. These connectors consist of multiple coaxial contacts of the same interface integrated
into a single connector module or shell. There are numerous options for these types of connectors, including those with reduced size and weight that provide excellent electromagnetic shielding and phase stability with low VSWR and insertion loss to 20 GHz for multiport connectors and to 40
GHz for mini-multiport connectors. See Figure 1 and 2 for examples.
BUNDLED CABLE SOLUTIONS
Densification creates numerous challenges related to installation, torquing, ensuring proper weather sealing and more. In addition, an increasing number of technologies such as 5G small cells have limited space for equipment, so minimizing size and weight are also key goals.
With so many components in such a small space, maintenance can be challenging. If an interconnect fails, it can be hard to troubleshoot the exact one. Moreover, installation can be a time-consuming, labor-intensive and logistical nightmare. Hooking up the right cables, ports and torquing can be difficult when working with multiple connections. Proper weather sealing is also necessary; it is imperative to ensure that the seal is secure but not over-torqued.
A bundled cable solution can help create the perfect flexible antenna jumper for applications requiring multiple runs, such as 5G. A spiral configuration of multiple flexible and ultra-flexible jumper cables can be created under a common polyurethane outer jacket to promote easy installation and
improved operation. The individual coaxial cable runs are spun together in a way that easily flexes, essentially creating a bundle, which is then run through a large jacket extruder where a ripcord is placed.
This design enables four or five individual cables to be fed into the back of an industry standard MQ4/MQ5 bundled connector, incorporating multiple RF ports and significantly reducing the number of cables that have to be hooked up. MQ4/MQ5 bundled solutions also save a lot of labor and enable
a more rugged solution. They also make the assembly more weatherproof and UV resistant.
Using the four- or five-conductor solution eliminates the need to create individual weather seals, resulting in tremendous labor savings. Furthermore, it reduces the need to worry about coupling torque, which is critical because all it takes is an error on just one weather seal to create a point of
ingress for water that could create a multitude of problems and even potentially shut the system down. With a bundled solution, the connection between the male and female cluster connectors is sealed to IP-67, as are the connector bodies and the transition from the cluster connector to the bundled cable. Any potential system troubleshooting becomes much easier. Finally, the possibility of hooking up the wrong cable to the wrong port is eliminated. The solution is keyed, so the cables can only be hooked up a certain way—no torque wrenches, know-how or special technique required.
Bundled solutions are optimal for high density challenges as they permit installation in tight spaces; instead of connecting multiple threaded connectors, just one will do the job. They are faster and easier to install and maintain and provide one firm, reliable connection to support consistent high performance. Their design has many use cases, thus becoming particularly popular in applications
where cable installations and rising operating frequencies demand coaxial cables and connectors to deliver high signal integrity and reliability. An example of this type of solution is the TMQ4 and TMQ5 bundled cable assemblies from Times Microwave Systems shown in Figure 3.
LOCKING MINIATURE BLIND MATES
A new generation of locking miniature blind mate connectors (TLMB) is specifically designed to overcome performance issues arising from typical SMP connectors’ susceptibility to electromagnetic interference (EMI) and electromagnetic compatibility (EMC) interference, liquid and salt ingress. Their rugged, sealed design is more durable to withstand harsh conditions and operate in severe environments. TLMB connectors retain the small form factor of the SMP for highly dense environments but add improved environmental, shielding and power capabilities, with a frequency
range from DC to 60 GHz.
While SMPs are still a valuable connector option for many designs, they pose problems as applications demand higher and higher frequencies. One of the critical issues is shielding and EMI.
Similarly, the SMP’s design reduces its ability to function without affecting other equipment in the same environment. The connector’s signal leakage issues often result in failed EMC tests. In short,
the SMP’s lack of proper electrical bonding and shielding exposes the conductor’s signal to external influence.
This signal leakage limits how closely the connectors can be placed in a single shell; without proper shielding, the contacts must be kept at a greater distance to prevent signal interference. With the improved shielding of a TLMB, more connectors and cables can be added in a much smaller footprint without interference issues.
Another major failure area in the SMP’s design makes them susceptible to ingress from saltwater, fuel and other contaminants. The lack of an environmental seal due to their mechanical openings makes SMPs prone to corrosion and failure. Another problem arises with using SMPs in high vibration applications, where their easy connect/ disconnect design makes them susceptible to unwanted de-mating in high vibration environments. TLMBs were created for high-reliability, high vibration environments such as military and aerospace. Areas where EMI may be an issue, such as
shipboard or aircraft, need an environmentally sealed and shielded connector.
The standard SMP may also disconnect in high vibration environments such as a carrier landing, weapons launch or any powerful weapons platform, making a locking miniature blind mate connector the ideal choice.
CABLE ASSEMBLIES FOR DENSELY PACKED IN-THE-BOX APPLICATIONS
Additionally, it may be optimal in high density applications to reduce the footprint required behind the connector to help install numerous cables into a very small space. Minimizing space between the cables and connectors is also necessary for the interconnect system to survive the high vibration and other harsh environmental conditions found in applications such as space and avionics.
New cable assemblies can be bent around tight corners and very closely behind the connector to minimize footprint, save space and simplify cable routing in tight spaces while offering low loss and optimized performance. Originally designed for space flight applications, this type of high performance assembly uses a compact, phase stable, highly flexible, micro becoming axial cable that can easily accommodate densely packed in-the-box applications. For example, Times Microwave System’s new InstaBend™ high performance microwave assemblies provide a flexible
preassembled design for interconnects between RF circuit cards, modules and enclosure panels. InstaBend is ideal for in-the-box applications with space constraints, including space flight, thermal vacuum, microwave test and other commercial and military applications. The cable can be bent very closely behind the connector, minimizing footprint, saving space and simplifying cable routing (see Figure 4). This also eliminates the need to protect the back of the connector.
Additionally, InstaBend provides these benefits at a dramatically reduced lead time compared to competing solutions. The high performance microwave assemblies are available in standard configurations or customized to meet an application’s specific needs. This new product’s ability to bend from connector to connector provides maximum flexibility and minimum use of available volume in high density, inside-the-box applications.
SUMMARY
As advanced new mission-critical technologies are introduced, RF interconnect requirements are changing drastically, including the need for novel solutions to accommodate extremely restricted space constraints and rising operating frequencies. New innovations in high density RF interconnects are emerging to deliver high signal integrity and reliability in increasingly dense environments.
When selecting the right high density RF cables and connectors, it is best to work with a partner whose engineers can identify the application’s unique needs and design an optimized, easier to use solution—creating better electrical, mechanical and environmental performance. Look for a supplier
with a long history of building quality cable and connectors, along with the skill, processes, techniques and materials to bring custom solutions for specific application needs to life
RF Interconnects for 5G Infrastructure and Applications
Pin Height

Phase Track® Cable – TF4™ Dielectric: The “Knee Replacement”

Optimizing Microwave Signal Transmissions In Extreme Cryogenic Environments
OPTIMIZING AN RF TRANSMISSION LINE
On Site Testing of Lightning Protection Devices
New Connector Field Installations Improve System Reliability
Connector Installation
New Connector Field Installations Improve System Reliability
By Kevin Moyher
Here is a short case history demonstrating a solution for reliable field-installed connectors use in high reliability wireless E911 systems
Across the country, CDMA, TDMA and GSM wireless communication sites are being upgraded to meet the requirements of the FCC’s Enhanced 911, or E911, mandate. Phase II of this ruling requires that network-based wireless location systems locate a wireless phone user to within 100 meters 67 percent of the time, and to within 300 meters 95 percent of the time. The quality and reliability of these systems is paramount; people’s lives may depend on it. Applications for this system are personal security, medical alerts, child tracking and accident response.
An Example of E911 Equipment
True Position is a leading supplier of the complex equipment that is integrated into cellular and PCS base stations to give them user location capability. True Position utilizes UTDOA (Uplink Time Difference of Arrival) technology to locate a subscriber’s cell phone. The LMU (Location Measurement Unit) is installed at each cell site. This equipment passively overlays the existing wireless network, sending critical data back to the operator’s Mobile Switching Centers where LCs (Location Calculators) perform the multipath mitigation algorithms. When a wireless phone user whose carrier employs True Position’s equipment dials 911 and activates the E911 network, the equipment in the area surrounding the caller is activated and begins to perform the complex calculations necessary to pinpoint the caller.
The reliability of this equipment is critical, and it has been optimized and ruggedized to perform with high reliability. However, there are only so many safe guards and safety measures that can be incorporated into the components themselves. The ultimate reliability of this system depends on the quality of the interconnecting cable runs. As shown in the photos of Figure 1, the E911 hardware has to be connected to each of the transmit and receive antenna runs, requiring multiple short interconnect cables. These cables are built from small core low-loss, flexible 50 ohm coaxial cable. True Position minimized some of the installation variables by using the QMA interface for these interconnecting runs. This interface can best be described as a high performance, quick connect SMA. The adoption of this interface eliminates the need for threading of small coupling nuts and the concern for achieving the proper mating torque.
Times Microwave has contributed to high performance and reliability of these systems, starting with the basic requirements of high quality cable and connectors with very good return loss. However, since the layout of every base station is different and the lengths of the interconnect cables vary accordingly, the cables must be cut and terminated in the field. This reality prompted the design of a series of EZ (spring finger center con- tact) connectors that interface with Times’ LMR-240 cable (Figure 2). Though QMAs are the dominant interface in the system, SMA and Type N connectors are also widely used. These EZ connectors eliminate the need for soldering in the field and solve the issues of pin height and pin to core gap. These three variables are often the largest contributors to inconsistency in the performance of field terminated interconnect cables.
The right angle EZs employ a unique design. Many spring finger right angle connectors have a 90° swept center pin with a mitered outer conductor. This design offers ease of termination at the expense of return loss. Times has taken the typical soldered right angle design and improved upon it. The straight brass center pin has been replaced by a straight beryllium copper pin that is bifurcated at the back end with a lead-in for the cable center conductor. This configuration has the ability to fine tune the impedance across the right angle. Where typical EZ right angles have a return loss weakness over a properly designed right angle solder connector, this new design actually has an advantage: excess solder build-up is no longer an issue. Going a step further with this design, a stop is placed inside the connector so that the pin can not be over extended beyond the center pin.
Optimization of the field terminated cables goes beyond connector design and includes the development of two easy-to-use termination tools. The first of these is a “one-step” cable stripping tool (ST-240EZ). Many small coaxial cable prepping tools are generic tools which are completely adjustable. These tools are capable of being adjusted to work with different cables but can be a real minefield in terms of potential termination problems (i.e., nicked outer braids, nicked center conductor, crushed core, improper strip lengths, etc.). The ST- 240 is a completely customized tool. The cable slides into a cable slot until it hits a stop. The blade package, containing two hardened alloy blades, is then released onto the cable, the index finger is placed through the loop at the end of the tools handle and the tool is spun clockwise around the cable for three to four full revolutions. The tool is then grasped as close to the cable as possible and pulled away from the cable, exposing the center conductor and tinned copper round wire braid.
This tool assures that the cable is stripped to the proper dimensions every time. It preps the core square and clean without crushing it or rip- ping the outer conductor and it preps the center conductor clean without nicking. The most important function which the tool performs is to expose the braid without nicking it. This is a very important requirement in the termination process that often gets overlooked. The braids on these small core flexible cables are of a very small diameter and a slight miscalculation with the pressure applied to a knife or a slight mis-adjustment of a variable stripping tool could effectively wipe out half or more of the braid, resulting in poor connector retention. The introduction of these EZ connectors for LMR-240, and the simple tools to assist with their termination, has created a nearly foolproof choice for the field assembly of short low-loss interconnect cables.

Microwave and RF Cable Assemblies: The Neglected System Component Part 2

Microwave and RF Cable Assemblies: The Neglected System Component Part 1
Making the Connection…With Coaxial Cable

Interpretation of Electrical Test Data with Regards to Microwave Cable Assemblies
Interpretation of Electrical Test Data with Regards to Microwave Cable Assemblies
Prepared By: Dave Slack
Originally published in RF Globalnet
June 3, 2002
A cable assembly provides two essential functions in a microwave or RF system.
These devices serve to mechanically connect an RF source to its load and to serve as a propagation
medium and waveguide for the RF signal.
A cable assembly should not be considered as hookup wire. It is a passive, TEM mode, microwave
device. As such, they are system components whose performance is just as important as directional
couplers, combiners or antennas or a host of other passive microwave components.
Cable assemblies are an integral part of the microwave system and their performance is critical to
overall system performance.
To ensure that the cable assembly being considered for use in a given system will perform well
several measurements of electrical performance are commonly made.
The primary measurement parameters used when evaluating microwave cable assemblies are Voltage Standing Wave Ratio (VSWR) and Insertion Loss. These are commonly referred to in quantitative terms where specifications such as VSWR of 1.4:1 maximum and insertion loss less than 1.5 dB.
While these numerical quantities are of great importance, especially when making a pass-fail judgment, they do not tell the whole story.
When attempting to understand why a cable assembly is not meeting its quantitative requirements it
is enormously valuable to understand the qualitative features of the insertion loss and VSWR
characteristics.
A quick glance at an insertion loss and VSWR plot can yield an abundance of understanding with regards to a cable assembly’s fitness for use.
When a load is connected directly to a source most of the power delivered by the source will be transferred into the load.
In situations where the source and load cannot be co-located the load may then be separated from
the source with a cable assembly “inserted” in between them. The amount that the power delivered to the source is reduced is called the “insertion loss”. This is the loss of power due to inserting the cable between the source and the load.
There are three primary factors contributing to overall insertion loss. These are the attenuation
of the cable, attenuation of the connectors and the mismatch loss due to imperfect impedance
matching.
Attenuation of cable and connectors are functions of their respective material and geometric
properties.
Some of the factors affecting attenuation are:
- Conductivity
- Surface finish
- Dissipation factor
- Propagation Velocity
- Line Size
- Impedance
- Frequency
Figure 1 depicts a typical insertion loss vs. frequency plot of a coaxial cable assembly.
Note that the fine grain ripple on the graph becomes more pronounced as frequency
increases. This is due to the mismatch loss that is a result of less than perfect impedance
matching and will be discussed later.
Total insertion loss is the sum of connector loss, cable loss and mismatch loss.
VSWR
The theorem of maximum power transfer states that the most efficient transfer of energy will occur
when load impedance matches that of the source delivering the power.
A 50 ohms source, connected to a 50-ohm load through a 50-ohm transmission line will be the most efficient system from a transfer of energy standpoint.
In a practical system all of these impedances are not exactly matched. At the point where two unequal impedances meet a discontinuity is created. This discontinuity causes some of the power to
be reflected back from the discontinuity with the balance being transferred forward.
This discontinuity can be quantified in terms of reflection coefficient. Once the reflection coefficient of a discontinuity is quantified the Voltage Standing Wave Ration (VSWR) can be calculated. This is a measure of the reflected voltage and ultimately, of the reflected (and transmitted) power.
Figure 2 illustrates a very simple case of a perfect system containing one, very simple discontinuity. A realistic system is composed of a virtually infinite number of cascaded discontinuities.
Reflection coefficients are complex quantities containing both magnitudes and phase angles. The
composite system makes up an array whose vector sum yields the composite VSWR vs. frequency
response of the system. Figure 3 illustrates impedance vs. time of a typical cable assembly.
Figure 4 illustrates the VSWR vs. Frequency plot of the cable assembly whose impedance characteristics is illustrated in figure 3.
Return Loss is another way of understanding the relative impedance match (or effectiveness of power transfer) of a cable assembly. Return loss is the ratio of power reflected to power delivered and can be calculated as follows:
Return Loss (dB) = 20 log l Γ l
The return loss vs. frequency graph of the above assembly is shown in Figure 5.
A VSWR plot, to the uninitiated, can be a very confusing plot. One is tempted to seek the maximum
value and make a “pass / fail” decision based on this value. In reality there is a wealth of information contained within this presentation.
A cable assembly, in its simplest sense, is a relatively uniform impedance cable with two
connectors installed on both ends. Each of these connectors typically has impedances that are
slightly different than the cable and probably slightly different than either the source or load.
These connectors are separated be the signal propagation time, or electrical length of the
assembly.
A standing wave pattern created by these two connectors will be a function of the magnitude and
phase angle of the two connector reflection and the electrical length separating them.
As frequency is incremented from lowest to highest operating frequencies the phase angle of the two
reflection coefficients, in relation to each other, also varies. If the swept frequency band is
wide enough the two interacting reflection coefficients will be in phase at some frequencies and out of phase at some frequencies.
When the relative phase angle is zero degrees the two magnitudes will algebraically add and VSWR
will be at a maximum. When the relative phase angle of the two are 180 degrees out of phase the
two, equal magnitude, reflection coefficients will subtract and VSWR will be minimum. If the magnitude of the two reflection coefficients are equal they will cancel each other completely at frequencies where they are 180 degrees out of phase.
When cable assemblies are longer the propagation delay is longer. This causes the frequency
differential between the peaks and nulls to become smaller. For a short assembly the VSWR vs.
Frequency plot has a long period to it and represents a rectified sine pattern. As the assembly
becomes longer the VSWR pattern takes on a fine grain “ripple” effect.
As the cable assembly deviates from this simple model towards a more practical model the VSWR
pattern becomes more complex. The individual parts of a connector will interact with each other.
The time delay between these parts is small. This causes a fine grain VSWR to be superimposed on a long flowing pattern.
Termination Problems
When the two primary reflections (usually the connectors) are equal, or close, in reflection
coefficient magnitude the VSWR maximums will be low and the VSWR minimums will be very close to unity.
This canceling effect is usually not complete because of the attenuation of the cable. This is why
a complete canceling may occur at lower frequencies and become less complete as frequency
increases.
When the VSWR nulls significantly deviate from 1.0:1 VSWR it is indicative of a problem with one of
the connectors. It is letting us know that the reflection coefficient magnitudes of the two connectors are no longer close to being equal.
This can be caused by high resistance contact points within the connector, poor solder quality, or a high reactive impedance mismatch caused by an incorrect dielectric.
Figure 9 illustrates two separate assemblies. One having a high VSWR and the other having a normal VSWR.
The high VSWR assembly is slightly longer in length (and higher in loss) such that their respective
curves do not overlay each other. From the quality of the curves the effect of the high VSWR on
insertion loss is readily apparent.
The fine grain ripple due to mismatch loss that is superimposed on the attenuation curve is much greater on the high VSWR assembly.
“Suckouts”
For purposes of theoretical analysis transmission lines are commonly modeled using lumped constant parameters. The distributed capacitances and inductances are lumped into discrete components from which transfer functions and other mathematical tools may be derived.
The lumped constant model of a coaxial transmission line is that of a multi pole, low pass
filter as shown in Figure 10.
For a coaxial system to work properly all of the mechanical mating parts must have complete contact, throughout 360 degrees of circumference of the inner and outer conductors. When
parts are not correctly assembled, or not mated with sufficient contact pressure, this 360-degree contact is not maintained and a resonance can result.
The resultant lumped constant model is illustrated in Figure 12. A parallel LC tank, at resonance,
presents very high impedance. This causes the transmission line model to have a band stop characteristic that is not desirable in most applications.
The center frequency and bandwidth of the band stop characteristic is a function of the degree of separation severity of the mismatched parts.
The effect on insertion loss and VSWR are illustrated in Figures 13 and 14.
The effect can be further noted when viewing impedance vs. time (distance) plot of an assembly having mismated or loose parts. Fig 15. It is evident upon inspection of the plot that the input connector displays significant “ringing” that is typical of a resonant condition.
Impedance Uniformity (structural return loss)
Until now we have been considering the cable part of a cable assembly to be of uniform impedance. We have considered the connectors, and their interactions, to be the cause of the VSWR effects. In most cases the connectors are the primary contributor to VSWR and the cable is the primary contributor to insertion loss.
There are cases where, for a variety of reasons, the cable impedance uniformity is less than perfect. This is illustrated in Figure 16.
These sorts of “structural” discontinuities yield a non-uniform, non-repetitive VSWR pattern. This type of pattern is typically referred to a high structural return loss as illustrated below.
Cable Spikes
When impedance discontinuities are very repetitive and consistently spaced there will be a specific frequency where all of these repetitive discontinuities will add. At this frequency a very magnitude, narrow band VSWR characteristic can be created.
This phenomena is commonly known as a “cable spike”. The larger the discontinuities, the more
consistent the spacing, and the longer the amount of cable affected the larger the cable spike can become.
This can be an especially frustrating problem in the manufacture of cable for use at microwave
frequencies. These cables are typically quite broad band so that any tendency to have a cable spike
will most likely occur somewhere within the operating band of the cable.
Most of the operations employed in the manufacture of cable involve rotating machinery. The repetitive nature of rotating machinery is often the cause of cable spikes. Through the use of quality machinery, diligent maintenance and active quality control measures the spike problem can
be effectively eliminated.
Figure 20 illustrates the impedance plot of the cable spike assembly. Figure 21 is a close up showing the fine impedance discontinuities and their repetitive nature. A period of 90 pico seconds causes the 11.1 GHz spike noted in Figure 18.
Modeing
A coaxial cable assembly is designed to operate in a Transverse Electro – Magnetic (TEM), or coaxial mode. In a TEM wave both the electric and magnetic fields are at right angles (transverse
to) to the direction of travel.
The coaxial structure will not support various “wave guide” modes of operation as long as the half
wavelength of the signal being propagated is less than the mean circumference of the coaxial
structure.
These higher order modes allow circulating fields to exist that are in a direction not transverse
to the direction of propagation. These circulating currents absorb energy that is no longer
available to be transferred to the intended load. These currents tend to be unpredictable and
unstable and are generally not desirable.
The maximum operating frequency, that is free of TE or TM modes, is referred to as the frequency of cutoff (fc). This is illustrated below.
A VSWR and insertion loss plot of a cable assembly operating beyond its cutoff frequency is shown in Figure 19 and 20.
Figures 24 and 25 are a 3 GHz section of Figures 22 and 23. These serve to illustrate that, unlike a cable spike, the effects of operation beyond cutoff are not always evident in the VSWR plot.
Dents
One of the more common causes of failure of a cable assembly is for the cable to become crushed or dented. Cable impedance is a function of geometry and propagation velocity of the dielectric core.
This can be calculated as follows:
where Zₒ is the impedance, Vg is the velocity of propagation, D is the outer conductor diameter and d is the center conductor diameter.
When the cable is crushed or dented the outer diameter (D) is reduced and the Vg is also reduced.
This lowers the impedance and causes an impedance discontinuity.
The following series of figures illustrates the effects on impedance and VSWR when a good assembly has dents imparted into it.
Contamination Ingress
Another common failure mode is that of contamination ingress into the dielectric of the cable structure. This can be caused by compromise of the vapor seal of the cable assembly or by the use
of solvents or other aromatic materials during the manufacture of the cable assemblies.
This failure manifests itself in the form of lower impedance where, the core is contaminated, as
well as an increase in insertion loss by more than the increased mismatch loss would normally indicate.
If the contamination ingress is due to solvents used in the installation of the connector the impedance discontinuity will be evident at the beginning of the cable assembly as shown in Figure
34.
The contamination may also enter the cable through a puncture or tear in the vapor barrier of the
cable. In this case the impedance discontinuity would appear in proximity to the leak.
Conclusion
With a discerning eye towards the qualitative presentation of cable assembly test data, the
discriminating consumer of these products can easily, and quickly, identify the most likely cause
of cable assembly problems.
Once the most likely cause is identified the real work of implementing root cause problem solving techniques and practices can begin.

How To Choose the Best Test Cable
A NOVEL SUPER-ROBUST HANDGRIP FOR COAXIAL CONNECTOR ASSEMBLIES
Don’t Overlook the RF Connector
Broadband Wireless
Don’t Overlook the RF Connector
Technical Primer: Using the Proper Connectors Can Be Critical in High-Frequency Applications
By Kevin Moyher
Connectors on an RF assembly are often taken for granted. In many cases the designer is satisfied if he has found a connector of the proper interface that will physically fit onto the cable that he intends to use. Impedance uniformity across a cable assembly is paramount in the efficient transmission of RF energy. The cable assembly is basically only as good as its weakest link. The time and money spent on high-quality, low-loss cable can be wasted if there are large impedance mismatches within the connectors, at the connector-cable interface and at the connector-device interface.
The Connector and Wave Reflection
Ideally, the RF connector will have a uniform impedance across its entire electrical path and a VSWR (voltage standing wave ratio) rating of 1.00:1. The VSWR value of a connector is the expression of the percentage of the input signal that is reflected back toward the source due to mismatches within the connector. This VSWR value can also be used to express the percentage of reflections across an entire assembly.
A uniform impedance across the connector, the cable and the connector-cable interface will allow the input signal of an RF transmission line to be efficiently transmitted to the output. In this case, reflections created by impedance mismatches will be nonexistent, and the losses across the assembly length will be strictly a function of the resistance of the conductors, the electrical properties of the dielectric and the shielding of the cable.
Connectors with greater impedance mismatches will have higher VSWR values associated with them. These VSWR values can be directly correlated with a value called mismatch loss (for example, a VSWR value of 5.85 has a mismatch loss of 3.021 dB).
The overall insertion loss for an assembly can be determined by calculating the theoretical
attenuation of the assembly and then adding all of the mismatch losses that would be associated with the assembly (i.e. cable, forward connector and aft connector). This calculated value represents a worst-case scenario. It would become reality if the peaks of the incident wave and all of the reflected waves were in phase with each other. This scenario is possible, but unlikely. However,
it is almost certain that the overall insertion loss of the assembly will increase as the reflections caused by mismatches along its length increase.
A perfect connector with a 1.00:1 VSWR is not possible, or I should say, it is not economically
viable. There are line-size transitions that are taking place within the connector. There are many variables involved in optimizing these line-size transitions. An abrupt transition may work well at lower frequencies, but this transition must be compensated when working at higher frequencies.
This is not an exact science. However, experienced connector designers can use time domain reflectometry to map the impedance mismatches across the connector. They can then improve the uniformity of the impedance across the connector. The art in doing this is not simply in finding a way to properly compensate the connector but in doing it in such a way that it can be produced economically.
VSWR Performance
VSWR performances of three 30-inch LMR assemblies are shown in Figures 1 and 2. The three graphs in Figure 1 display the performance of LMR-400 assemblies terminated with type N male connectors. The bottom graph of Figure 1 shows the performance of an assembly that was constructed with Times Microwave Systems’ connectors, while the top and middle graphs display the performance of assemblies constructed from connectors supplied by two other leading connector suppliers.
The first thing that comes to mind when looking at these traces in Figure 1 is that the nodes are similarly shaped and very cyclical, indicating that the cable itself has a very uniform impedance. In the event that the cable varied in impedance, the trace would look much more ragged. The VSWR trace of a cable with very poor impedance uniformity would look almost like random noise.
Based on this information and the fact that each of these 30-inch assemblies was made from the same lot of cable, we know that the steadily increasing VSWR with frequency in the middle graph of Figure 1 and the high VSWR in the midband shown in the top graph can be attributed to reflections
due to impedance mismatches within the connectors.
These three curves in Figure 1 demonstrate how the size and material transitions within a particular connector design may be compensated to perform well up to a certain frequency. It is also possible to design a connector that may perform very well in a particular band but reflect a larger percentage of the input signal at frequencies both above and below the designated band.
Figure 2 compares three 30-inch LMR- 600 assemblies. The assembly represented in the bottom graph of Figure 2 has been built with Times Microwave Systems’ EZ-600-
NMH connectors. The assemblies represented in the top and middle graphs of Figure 2 have been built with connectors from two other leading suppliers. The top and middle graphs indicate good performance in the low band, excellent performance at midband and very quick roll off in the high band. The assembly represented in the bottom graph of Figure 2 indicates good performance across
the entire band, with excellent performance at the high ISM (Industrial Scientific Medical) band.
Connector Design for High Frequencies
It gets increasingly difficult with connectors, as with cable, to design, build and maintain the tight process controls that are necessary to achieve a high level of performance over a broad frequency band. It’s especially difficult as the frequencies climb well beyond the 1 GHz level, such as in the
5.8-GHz ISM band. Although it is possible to optimize connectors to perform well in certain bands, it is rarely viable from an economic standpoint.
Most connectors are rated for broadband performance to a specific maximum frequency. Unfortunately, most manufacturers of commercial RF connectors have not been able to keep up with the improvements that would be necessary to obtain reasonably good performance at the 3.7- or 5.8-GHz level, never mind optimal performance.
As little as three years ago, most applications were operating below 1 GHz; as recently as two years ago, most applications for commercial cable and connectors were operating below 2 GHz. It is these cellular and PCS (personal communications service) bands for which most connectors were designed. Someone working in these bands could basically pull any connector off a shelf and it would be a pretty safe bet that the performance would at least be respectable. Most connector manufacturers were slow to understand that a connector that was sufficient in a PCS application at 2 GHz may not meet the requirements for a 2.4 GHz application in the ISM band.
The proliferation of data applications in the ISM bands has placed certain demands on connector performance. These bands are unlicensed, and therefore the Federal Communications Commission has placed power limitations on transmissions in these bands. The need to be assured that there is a
sufficient transmit signal — but at the same time, making sure that the transmit power never exceeds the maximum allowable power — has, in many cases, created a demand for low-loss cable assemblies that are consistent and predictable in performance.
The nature of data transmission itself has also pushed systems to reduce noise levels to their absolute minimum. The best way to do this is to minimize the power levels of the system. Hence, there’s a need for low-loss cable, and, just as importantly, low-loss assemblies. As an added challenge, some of these systems are now operating in the 5.8- GHz band.
A desirable feature to have in any connector, and especially in one that must be field installed, is a captivated pin. The pin may be of a spring-finger design and permanently pressed into the dielectric or it might have a shoulder on it that will make positive contact with the bottom of a counter bore in
the connector dielectric. It’s not a stretch to imagine that the pin height of a connector with a noncaptivated pin, when installed in the field, may be 10 to 20 mils off. This error will create shifts in impedance throughout the connector, especially if there are many diameter transitions in the pin.
The Cable Design Factor
There are an enormous number of 50- ohm coaxial cable designs available. The designs encompass standard RG designations, as well as specific requirements that have arisen over the years. These designs have been devised to optimize certain parameters of the cable, such as attenuation, impedance uniformity, velocity, time delay, diameter, bend radius, flexibility, temperature range of operation and weight.
These parameters are optimized by varying center conductor, dielectric, outer conductor, and jacket materials and sizes. Optimization is also accomplished by varying the processes by which the cable is produced. Although most of these cables are 50-ohm cables, many of them present their own unique physical considerations when they are terminated with a connector.
Times Microwave Systems makes a variety of 50-ohm coaxial cables, more than any other manufacturer. The product line includes RG cables and the LMR line of low-loss flexible cable that is widely used in telecommunications and has become the accepted standard for wireless data.
The Connector-Cable Interface
There are an enormous number of connector interfaces that are in use today.
However, in wireless communications more often than not, we find ourselves working
with SMAs, TNCs, Ns or 7/16 DINs. The need for economic solutions in the development
of wireless infrastructure requires us to use the smallest diameter cable that will keep us within our loss budget and meet any other requirements that the system will place on the cable.
Factoring in the need to work with the smallest cable available, it can be quite a task to find the ideal connector for a particular cable. Considerations include the variety of cable designs, the number of connector interfaces that are dealt with, and issues such as gender, straight or right angle, clamp or
crimp, connector material and plating. Additionally, most cable manufacturers do not design or build connectors, and most connector manufacturers do not design or build cable. Hence, a certain level of frustration can be expected.
For purposes of discussion, we will assume that we are working with cable that has a uniform, 50-ohm impedance. Also, we assume that our connectors have a uniform impedance across their length (including the compensation necessary to carry out the line-size transition from the interface to the
core diameter that is being considered). At this point, the most important consideration is the mechanical fit between the transfer body of the connector (the effective outer conductor) and the outer conductor or shield of the cable itself. Ideally, this interface will be smooth and mechanically intimate around the entire 360-degree circumference of the connector.
Some connectors are designed to snugly fit over the outer shield of a cable. Other connectors are designed to fit snugly over the dielectric and have the shield or outer conductor crimped or clamped to the outer surface of the transfer body of the connector. In any case, the inner diameter of the
outer conductor must be maintained as best as possible when making the cable-connector
transition, and this transition must be mechanically sound. It doesn’t do any good to have an assembly that will perform reasonably well on a workbench but deteriorates quickly when exposed to real-life situations such as wind, vibration and temperature shifts.
Conclusion
As the frequencies of new applications continue to rise and performance requirements
become increasingly demanding, the connector must be looked at closely. Factors include the mechanical variables that will affect overall electrical performance, performance
under extreme conditions and the long-term ability to withstand the environment. Also, each connector has its own impedance characteristics similar to a fingerprint. Various connector designs will be associated with different VSWR values at a given frequency, and, in some cases, may have a significant impact on the overall insertion loss of a microwave assembly.
About the Author:
Kevin Moyher is a sales engineer at Times Microwave Systems. Times Microwave Systems is a division of Smith Industries PLC and has been involved in the design and manufacture of high performance coaxial cables for more than 50 years.

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The New TCA: Solutions for Avionics Installations Webinar Summary
Summary
With a long history of serving the aviation community, we understand our customers’ needs for reliability, quality, and delivery. As a result of that decades-long heritage, Times Microwave designed a complete system of cables, connectors, tools, and accessories that make installation easy and clean—the TCA product family. Carrie Obedzinski and Kevin Moyher, two leading industry experts, discuss the challenges and requirements of airframe installations. From reduced inventory and foreign object debris (FOD) to time and cost savings, customers around the world have tested and approved thousands of our TCA assemblies.
Watch the video or read the session notes below.
Session Notes
Times Microwave Systems’ engineering and manufacturing capabilities enable us to deliver RF products that meet the most demanding and unusual aviation requirements, including customized solutions and product design, installation, regulatory compliance, and performance improvement. Most importantly, with fully integrated manufacturing production, we have all the necessary assembly and testing capabilities in-house. We deliver RF interconnect solutions from conception through flight testing and production.
This webinar will detail some of the challenges and requirements of airframe installations and present some excellent solutions for making them easier, more efficient, and reliable.
We have been manufacturing our three most popular 50 Ohm aviation cables, spanning from the HF to the KA band, for many years. Times’ LMR®-FR, for example, is one of the most popular products for wireless applications. It is very easy to terminate in the field and comes with a complete line of connectors and tooling. Its fire-retardant FR jacket meets FAA flame test requirements. MaxGain® is our higher-frequency band cable; it’s an outstanding solution for KU and KA-SATCOM feeders. TCA, the focus of this webinar, is our high-performance cable used for higher temperature ranges up to 200°C.
There is some overlap between our avionics solutions because multiple products are suitable for certain applications. Times’ experienced engineering team members can help you determine which product to use based on your requirements such as flexibility or in-field assembly; or we can even create a new solution if needed, as we specialize in custom-engineered cable assemblies.
The TCA Product Line
We have been listening to our aviation customers—visiting them on site to understand what is important to their companies. Maintenance and safety are typically mentioned by installers, procurement and management alike.
Our aviation customers are also focused more than ever on minimizing waste, improving efficiencies, and reducing costs and inventories, including time savings in manufacturing processes and MRO aircraft installations. To satisfy these priorities, we have expanded our TCA product line to include a complete end-to-end RF interconnect solution for avionics, including cables, modular connectors, tooling and a pulling nose tool.
The TCA product line features Times’ lightweight, low-loss, high-temperature, highly flexible TCA cable, ideal for meeting avionics’ critical electrical and mechanical performance requirements for applications including satellite communications, collision avoidance, navigation, and more. TCA is great for routing cable through tight runs. It is an industry-standard construction and can satisfy an equivalent drop-in replacement on many specs. There are multiple shielding layers to reduce interference.
Connectors
The TCA flight-friendly modular connector system makes terminating the cable quick and easy while ensuring optimal electrical and mechanical performance. Modularized design enables the user to install the connectors with the configuration that best fits the final system.
The TCA connectors have 2-Nickel or bi-metal plating for excellent corrosion resistance and optimized VSWR performance. No braid trimming is needed during assembly, so this system helps reduce foreign object debris (FOD).
Once installed, there are many different standardized front ends to choose from. TCA’s modular concept also helps improve troubleshooting and repair—the user can take off the connector fronts and change them out, instead of completely removing the entire connector. Because the system uses the same intermediate heads, you can reduce inventory costs and risks, buying the parts you need for numerous connector configurations. They also meet IP 67 standards for moisture ingress.
Unique, All-in-one Prep Tools
- Maintenance personnel and installers sometimes work with razor blades and knives while hanging upside down, trying to fit multiple connector assemblies and terminate them inside the aircraft. The TCA product line includes unique, all-in-one prep tools for simple, safe and repeatable cable termination including the ST-3520, ST-31156 and ST-3112. Users can also save time by pre-terminating the assemblies with the cable entry and using TCA’s reusable pulling eye to “fish” the assembly through the fuselage of an aircraft. This helps cut down on tooling, debris and installation damage.
TCA tools will trim the cable to a proper conductor and perfect exposure length for modular connector assembly. The tools are supplied with a snap cover to help maintain control of cable debris for cleanroom and airplane worksites. It’s another way to help reduce the likelihood of FOD.
The tools help ensure repeatable prep because all assemblers and installers use are using a standard tool and process to ensure consistency in both electrical and mechanical performance.
The TCA product line ultimately helps make the installers’ job easier, safer, quicker, and more effective with less tooling needed, less debris, and repeatable performance terminations.
Q&A
- We have a question about the modular connections. You mentioned using Loctite. How would you disconnect that in the field?
- I have concerns using a razor blade against the center conductor. Are there concerns about damaging the cable?
To learn the answers and hear the full detail provided in the webinar, register now!

The Challenges of High Power in RF Applications Webinar Summary
Summary
This presentation will tackle the nuances of high-power applications involving coaxial cable assemblies. Different types of power and their impact on cable integrity will be discussed along with case studies that show how coaxial design can make the difference between safe operation or potentially dangerous operating conditions.
Watch the video or read the session notes below.
Session Notes
How Different Types of Power Affect Coaxial Cable Performance
When it comes to high power issues related to coaxial cable assemblies, it’s important to understand how power is classified and how it is used in real-world settings:
- High current: Found in industrial applications like semiconductors
- High voltage: Found in energy storage of high power, fractional duty cycle applications
- High power: Found in aerospace applications such as electronic warfare
High Current
Generally, current carrying capability is directly proportional to the crossed area of conductors. Therefore, the larger the conductor, the lower the resistance, the higher the current carrying capability. This drives the need for large cables and connectors.
Similar to a water pipe, more current can efficiently be produced through a larger conductor, which can be accomplished by simplifying the conductor design. A conductor with fewer piece parts and contact points provides a more robust design.
High current can also lead to sources of localized hotspots and weak spots in the design, and there are specific techniques and design features that can mitigate that issue.
High Voltage
High voltage power has arcs and flash-overs, essentially miniature versions of lightning bolts. Like lightning bolts—where huge amounts of charge are built up between the clouds and the surface of the Earth—voltage can increase between a generator and the ground to the point that it can no longer withstand the voltage and is released.
In this application, it is not so much about the size of the conductors but the capability to isolate and insulate one conductor from the other, or the cloud from the ground. This can be achieved by putting a high dielectric strength insulator between the conductors.
High Power
High power is thermal-related, continuous wave (CW) energy. The issue here isn’t voltage or current; it is the heat that is generated. When power is pumped into a cable assembly, some loss or inefficiencies occur. That lost power must be dissipated.
The issues are generally thermal and heat buildup, and the cable’s ability to transfer heat from its internal environment to the external environment. One mitigation technique is to increase the surface area of the component to radiate heat.
Conclusion
When failure modes happen, they can be dramatically catastrophic. Therefore, it is important to choose the right components, ensure that those components are designed to mate together, and that the cable and connector interface are designed to work together.
It is critical to use a connector that’s designed specifically for a cable and for a specific power application. They should also be installed and assembled by people who are experienced and understand the issues.
Q&A
Following are the questions that were asked by the audience:
- What is the most important component when selecting an assembly for high power?
- Does electrical performance change as cables get hot? What can we do to control or mitigate that?
To learn the answers and hear the full detail provided in the webinar, register now!
RF Interconnect Solutions for Complex Antenna Installations Webinar Summary
Summary
In this session, Dave provides an overview on how to design solutions for challenging airframe antenna applications. In addition, Dave discussed the nuances of working within the aviation space, and how Times Microwaves’ aircraft applications are designed to work in the challenging conditions that military-grade aircrafts endure on a daily basis. For example, the unique properties of a Times Microwave military/tactical-class feeder antenna lineup is designed to be equal parts durable and repairable for quick fixes on popular military aircraft like the C17.
Watch the video or read the session notes below.
Session Notes
A typical aircraft antenna installation involves a two-port antenna with a TNC female and an N female, a double plate matching the arc of the aircraft, and two cable assemblies. Once mated, the antenna is attached to the aircraft, and the two connectors attach to the antenna. However, this is 1960s technology. Let’s see what we can do about that.
There are standard technical considerations in terms of maintenance and access with an antenna mount located on an aircraft:
- The environmental seal, especially on lower antennas
- Mating life (and potential disconnections)
- Electrical performance over vibration
To address these concerns more effectively, let’s discuss a blind mating of the same antenna. This involves identical double plate and cable assemblies, but the N and the TNC connectors are replaced with blind mate versions. This eliminates the coupling nut and the lock wire scheme in favor of a captive spring column.
The alignment sleeves are attached to the antenna, one N and one TNC. Once these are mated, it turns into a blind mate-able surface. This stainless-steel alignment sleeve has turn rings, one that seals the threads from the outside in, and another that seals to an interface. To make this mount, the receiver sleeve is put up and then mounted to the doubler plate itself, and based upon the location and the height of the antenna, the zero position of the receiver sleeve is determined. Each of these receiver sleeves has a C-clip on it to hold it in place and the base connector threads directly onto it.
Environmental Sealing and Mating Life
Anytime there is a male, female TNC or a male female, as the connectors mount, they typically wear out at well under 500 mates. Additionally, after 500 mates and de-mates, a lot of metal debris has been generated that has likely filled that interface, resulting in potential electrical issues.
With the blind mate solution, as the nose cone is closed, the four alignment sleeves engage into a bracket that has a slight rotation on it. The springs engage as the nose cone is tightened in place. This type of antenna junction has been tested for wear and tear, resulting in 5,000+ mates with no failures.
Vibration and Electrical Performance
This example details an F35-C carrier landing condition with a significantly high vibration profile. On the right-hand nose door, there is a microwave landing system and an integrated carrier landing system. Each antenna contains a connector. In a normal test environment, a Band Aid connector such as a TMA can be attached. This is a three or four prong mated connector that enables antenna testing, antenna patterns, etc.
However, these landing system antennas are located on the inside of the nose door on a low observable aircraft. To find an airport or a ship, that nose door has to be opened—and this happens at up to 300 knots, which is equivalent to about a Class Five hurricane in the internal cavity. The problem with mounting a typical right-angle connector to one of these antennas in that kind of a vibration profile is that they tend to break.
Instead of continuing to mount the antenna the same way, we came up with the idea of using a multiport connector instead. Once the antenna has mated, it gets an environmental seal that engages the amount necessary for tolerancing. However, no motion is generated as a function of the vibration profile—it’s basically all neutralized at the bracket. The result is a very high performing RF interface at 300 knots in the carrier landing environment.
Q&A
Following are the questions that were asked by the audience:
- Can any antenna be made into a blind mate antenna?
- What if I want to put a gasket under my own antenna? Does the blind mate allow for that additional thickness?
- Are blind mate connectors recommended for high PIM requirements?
- Is most cable compatible with a blind mate?
- Could a blind mate be used with a Mil-Tec line or a Phase Track line?
- How much height is added to the blind mate or how much does a blind mate system add to the antenna?
- What about other applications, for example, or LRU boxes?
- Is there an application in space launch?
- Can you speak to tolerances of vibration levels?
- Are there drawings available of designs that have been done?
To learn the answers and hear the full detail provided in the webinar, register now!

RF in Space: 5 Steps to Find the Best Interconnect Supplier Webinar Summary
Summary
Searching and qualifying an RF interconnect supplier for space applications can be a lengthy and costly process. Some suppliers offer standard qualifications and documentation for basic products in hopes of simplifying this process. But nothing is standard, or easy, in space. In this session, Maria explains the 5 steps for evaluating an RF partner’s capability to handle the custom designs, special testing and qualifications required in space.
Watch the video or read the session notes below.
Session Notes
Designing a crucial interconnect system that will perform well and withstand the extraordinary environmental and technical conditions of space, reliably and consistently over long periods of time, is not like designing just any RF interconnect system. The conditions encountered in space are unique and require special, highly customized solutions to prevent failure.
Custom designs, special testing and qualifications, and new product development for space applications require experience and commitment. “Standard” RF systems are not good enough in space. It’s important to thoroughly evaluate the capabilities of an RF supplier to ensure a positive outcome.
5 Steps to Find the Best RF interconnect Supplier
To ensure the best possible performance for these special applications, as expediently and cost-effectively as possible, consider your RF partner’s:
- Qualifications and heritage
Many suppliers offer a good list of standard qualifications, but in space, your requirements may be unique. Look for partners that have experience in space, and in other areas such as military and defense. - Dedicated technical experts
Always ask to speak with technical experts. The complexity of space applications requires an effective partnership; choose a supplier that will work collaboratively as an extension of your design team. You’re not looking for a standard solution, so it’s important that your RF supplier’s technical team asks questions and listens to understand your unique needs. Don’t work with a supplier that’s committed to selling you the same product they’re selling everyone else. Your supplier should help you understand the electrical and mechanical trade-offs particular to your application, as well. - Breadth of products
A provider that offers a broad range of products is simply better equipped to sell you the right system for your application. You want to be able to select the right material, choose from multiple cable constructions, various connector designs (low power, high power, etc.) and assembly techniques, all from the same supplier. Plenty of technical standards must be met for products to be deployed in space, such as using only acceptable materials or mil-spec cable constructions. There is, however, no standard for how to apply these materials to construct an RF solution that is reliable time after time. That is where your supplier’s expertise and access to a full range of product options are needed. - Manufacturing execution
Ideally your supplier has all the technology and products you need and understands how to put them together into a final product. The next qualification to consider is the supplier’s manufacturing operations. Does the company have robust facilities and processes to support execution? Cleanroom manufacturing capabilities are key. Traceability is also important for managing all the piece parts that make the complicated assemblies. What quality standards does the supplier follow? What about extended services? - Agility
Be sure to choose an RF partner that is strong enough, financially and operationally, to deliver and survive through turbulent times. The last year has proven just how important it is to always remain agile and adaptable, in business and in life. Bad things sometimes happen. Can your supplier adjust quickly? The right partner will flex with you to deliver the value you need, every time.
All five selection criteria are tied to crucial performance capabilities, so consider their importance when evaluating potential RF suppliers. Choose wisely and enjoy a successful outcome that lasts.
To hear the full detail provided in the webinar, register now!

RF Applications: The Big Picture Webinar Summary
Summary
In this session, Dave provides an overview of Times Microwave’s expertise in designing coaxial cable solutions for a wide range of applications. Starting with the company’s deep experience in supporting electronic warfare systems, Dave explores how the company has adapted to enhance its capabilities to meet the changing needs of industries that demand more power and precision from cabling and measurement solutions. The webinar also examines how the Times Microwave approach is helping to solve challenges that would be nearly impossible to address without a flexible, scalable coaxial cable application ready for deployment.
Watch the video or read the session notes below.
Session Notes
There are five common RF use cases that require coaxial cables and connectors, and each type has its individual characteristics and challenges.
Communication
A traditional place for coaxial cables has been in wireless communications, including mobile/telecom, two-way radio, public mobile radio/land mobile radio, satellite communications and military communications. The challenge with these types of voice-based applications is the signal to noise ratio. This is critical as any degradation of the signal will cause information to be lost.
Therefore, factors that must be considered in determining the optimal coaxial cables and connectors include low loss, shielding so that signals from outside can’t interfere, and reliability with 99.999% up time. This has been a traditional application for Times Microwave LMR® cables. The product line up has evolved to include additional options to meet the needs of 5G and Low-PIM such as SPP™, TFT, small cell cables and more. We also have TCOM cables for deploying emergency cell sites.
Vision
In this case, RF is used as a way of viewing the world, most often in places where the eyes cannot see. The classic example is radar. Essentially, vision applications use RF signals to locate and identify potential threats, landscape features, and more. This type of system is typically found in military airframe electronic warfare systems, ground radar, anti-missile defense, guidance systems, aviation collision avoidance and similar applications.
Times Microwave has a long legacy creating optimized solutions for military airframe electronic warfare systems and many other related technologies. The common challenge is the multiple antennas and location sensors that all come back to a common point. Vision systems work by looking at the differences.
So, what’s the challenge when it comes to the cabling? One, these systems are in difficult places— extreme and highly variable conditions in terms of elevation, temperature, and more—and the signals need to travel at consistent speed independent of these elements.
This is critical as unaccounted-for variations could mean a system is “looking” in the wrong place. Additionally, if any phase or amplitude errors are being introduced into the multi-antenna system, it will cause a problem. Therefore, amplitude and phase stability across temperature and between cables is a key challenge in finding the right coaxial cable and connector solution for vision applications.
Data Systems
Sensors and other data systems are a big investment area now. These are systems that are essentially designed to get feedback needed to understand what is going on in a particular environment. An example is measuring the water content in soil to optimize field irrigation.
What is the challenge with sensors? They are typically used in extreme environments or locations that are difficult to access. For example, it is very difficult to do soil samples every morning on a 100-acre cornfield, so sensors are used. They are also useful in contaminated areas, or nuclear applications where it is not safe. This means that once the cable is installed, it might not be easily accessible for replacement.
Additionally, even though the process typically involves a quick measurement from a sensor connected to an antenna, reliability is key. If a critical system dependent on a sensor does not work, things can quickly go haywire.
Data systems require coaxial cable solutions that can withstand the rigors of these important applications. Times Microwave engineers are skilled in looking at this intriguing world and figuring out how to architect the best interconnect solutions to meet its challenges.
Test and Measurement
Test and measurement applications are used to test RF equipment during the design and production stages. An example of this is a program testing electronic warfare systems before they go into F-35 aircraft to ensure they can identify potential threats with the utmost reliability.
This environment requires unique coaxial cables and connector solutions— repeatability, reliability, and reproducibility are critical to make sure the cable itself is not introducing uncertainty to the test. This includes ensuring amplitude (low loss) and phase stability. Flexure is also key as these systems (and cables) are connected and disconnected often and are used repeatedly, so the connectors must be able to withstand extensive handling.
This use case also fits nicely with Times’ unique capabilities and products. Test and measurement requirements often demand a special type of cable—for example, one that needs to be flexed or bundled with another type of cable into a multi-pin type of connector—and Times will tailor a custom solution for the application.
High Power
These applications vary a bit from those previously mentioned because RF is used to transmit power in this case (such as activating a magnet or gas) rather than a signal. RF is used in these instances because cables are easier to install than pipes or other options. Examples include lasers, deposition equipment, physics test equipment, microwave ablation, industrial microwave ovens and MRI machines.
Therefore, key system parameters include flexibility and low loss. Power also generates heat, so the cable jacket temperature needs to be optimized for a particular power level. Materials and constructions are important to prevent overheating and to ensure ease of installation.
What Makes Times Microwave Unique?
Coaxial cable technology is being used in places you’ve likely never thought of before. Times Microwave applies its deep knowledge of this technology and dedicated engineers to create coaxial cable solutions for many different applications—whether the application is communications, vision, data systems, test and measurement, high power, or anything else. Bring us your tough challenges and I promise with almost 99.999% certainty that Times Microwave will be able to come up with a solution that meets your needs.

Reliable Solutions for Test and Measurement Webinar Summary
Summary
In this session, John explains how Times Microwave Systems’ test cables are used in test and measurement applications, and how the company’s core products are suited for various uses. He also explains how higher frequency ranges and the rise of 5G are driving development of more advanced cabling products, with more robust features and higher levels of customization now possible. Finally, the session drills deeper into popular products like Clarity™, Silverline®, Silverline®-Extra Flex, and Silverline®-VNA and how they are being used in the testing world today.
Watch the video or read the session notes below.
Session Notes
Test leads are used in essentially every manufacturing space related to electronics, avionics, test equipment, semiconductors, and more.
RF testing requires unique coaxial cable and connector solutions. The cable assemblies must be durable enough to withstand extensive handling and continuous movement from frequent connecting and disconnecting, while maintaining precise repeatability of measurement and reliable electrical performance. It is critical that the cable, cable assembly and connector do not introduce any problems.
New technologies such as 5G have introduced more testing challenges. The increased speed of 5G is achieved in part by using higher-frequency radio waves. Unlike previous cellular technology generations that were focused on a specific frequency band, 5G operates across a much larger frequency range. For example, 5G can range from 450 MHz to 3.9 GHz, and up to 20-52.6 GHz millimeter-wave bands for high-speed operations. It also encompasses unlicensed frequency bands, such as the 6 GHz band.
Rapidly advancing technologies are also increasing the complexity of test setups, requiring more test leads and connection points than ever before. This makes it necessary to revisit how connection points and test leads are built as well as the different types of connectors available—while ensuring that the latest test assemblies work in concert with the changes made by test equipment manufacturers.
Another key aspect is related to the need to constantly move the cables around. Movement introduces phase change, which can impact measurement accuracy. Robust cabling is therefore critical to keep phase as stable as possible.
Additionally, when testing technologies such as 5G, the source and receiver might be running at two different frequencies at once. A phase-stable assembly will help ensure that harmonics are not introduced back into the system.
Times Microwave SilverLine® and Clarity™ Solutions
SilverLine test cables are cost-effective, durable, high-performance cable assemblies designed for use in a broad range of test and interconnect applications. The PTFE dielectric cable features stainless steel connectors and a molded strain relief system, providing long life and excellent phase stability in applications where the cables are repeatedly flexed and mated/unmated. Because Silverline tolerates a very wide temperature range – up to 125 degrees Celsius, it can also be used outside of a test bench.
SilverLine-ExtraFlex was designed for testing delicate components such as exposed RF circuits with edge launch connectors. It uses Times’ proprietary TF-4 dielectric, exhibiting a very linear phase change from 0ºC to +30ºC. It also uses the injection-molded strain relief system for extremely good isolation, and the same robust, proven connector attachment system as SilverLine.
Silverline-VNA cables are designed for the highest frequencies presently available, 70 GHz through 110 GHz. Their construction method is different than the others, as there is no unarmored option, to keep phase stability in check.
Times Microwave’s Clarity line includes highly stable RF cables with flex in a very robust package for accurate measurement. It features excellent phase stability, extremely low loss, an ergonomic molded boot and a large connector selection. Utilizing the flexible TF4 dielectric allows for accurate S parameter measurements and even when movement occurs in the production environment, the proven solutions cover a wide frequency range from 18 GHz to 50 GHz.
It is also important to use a very flexible cable material that can be moved around on a test bench, either in R&D or in a production environment. Testing often moves from module to module. With high frequencies, this could require recalibration every time a module or cable is moved. However, using a cable that can bend and flex will greatly reduce the amount of recalibration required while maintaining stability. Where Clarity really shines is its ability to connect and disconnect without having to do different calibrations in between.
Q&A
Following are some of the questions that were asked by the audience:
- What is the mating cycle for your test leads?
- What is the difference between an LMR and a test cable?
- What are the common failing mechanisms for test leads and where do they fail?
To learn the answers and hear the full detail provided in the webinar, register now!

Phase 102 Webinar Summary
Summary
The webinar is the second in a two-part series on phase stable cable assemblies and electrical length changes within cable assemblies in aerospace engineering and space technology development applications, among others. In this session, Dave Slack digs deeper into the impact of temperature on phase behavior. He explains the polytetrafluoroethylene (PTFE, also known Teflon™) “knee” that exists in some cables and how it impacts their phase performance. Slack also provides guidance on minimizing those effects with special materials, such as cables made from silicon dioxide (SiO2) and TF4.
Watch the video or read the session notes below.
Session Notes
A typical phase versus temperature signature of a flight-grade cable, circa 1995, would have been a 76% velocity cable made with a PTFE core. These cables were very rugged and resistant to damage during installation and maintenance.
Typically, there would be a relatively flat phase/temperature slope below room temperature. However, at room temperature, there is an abrupt jump that changes the phase temperature profile. This is due to a peculiarity of Teflon—a nearly perfect dielectric material for cable, RF and microwave applications because it has a constant dissipation factor as well as a constant loss tangent across a wide range of frequencies and temperatures. However, Teflon undergoes a mechanical or materials phase transition in which it changes density by about a percent and a half between 18-22 degrees Celsius, or 64-72 degrees Fahrenheit.
That change in density also causes a change in dielectric constant, which, as discussed in the Phase Stable Assemblies 101 webinar, creates a velocity change. This in turn produces an abrupt change in electrical length—a very common phenomenon known as the Teflon knee, or the PTFE knee.
A cable assembly gets electrically longer as it gets colder, and shorter as it gets warmer – contrary to what one might expect. Electrical length is proportional to physical length. Metals expand as they get warmer and contract as they get colder but as that happens, the dielectric constant expands and contracts as well and its density changes, altering the velocity. The dielectric effects of the plastic offset and dominate the metal effects.
Phase-matched cables are in pairs or groupings. As temperature changes to cold or warm extremes, they don’t exactly track together; the phase match degrades just slightly. That small amount of degradation is known as its phase tracking characteristic.
In a practical situation, a cable assembly might be phase matched to the initial assembly with a tolerance plus or minus a degree. The slope is the same, but it is offset by that initial match. The uncertainties and errors that accumulate with changes in temperature are the initial phase match plus the phase tracking; the two add to each other.
In another scenario, there may be two cable type families – a full-density and low-density PTFE. The vertical scaling is very large, in an 8,000 part-per-million window. Full-density solid Teflon actually takes up every bit of that scale. It has a relatively extreme slope below and above the knee, and a very pronounced step function during the phase transition temperature.
In the following example, we compare this against the low-density PTFE, with 10 cable assemblies of each family superimposed on top of each other, all phase matched at room temperature, tested and plotted across temperature. As it changes to extreme heat or cold, the cables are no longer perfectly phase matched; they differ from each other.
We tested two cable assemblies to look at phase versus frequency. One cable is a PhaseTrack® cable, and the other is a standard PTFE cable. When a freeze spray cools the cables down, the PhaseTrack cable stays consistent, whereas the PTFE changes because of the phase temperature knee. That causes antenna beam forming characteristics to defocus.
Because of these complexities, there is value in dealing with a supplier that offers a range of different technologies, and can provide optimized solutions for each unique application.
To hear the full detail provided in the webinar, register now!

Phase 101 Webinar Summary
Summary
The webinar is the first in a two-part series on phase stable assemblies and electrical length changes within cable assemblies. In this session, Dave Slack shares his insights on the importance of phase in cable assemblies. He explains what it is, why it matters, and how it can be properly specified for precise performance requirements in aerospace engineering, space technology, and more.
Watch the video or read the session notes below.
Session Notes
What is Phase?
Phase is a key parameter for detection and measurement in many RF/microwave systems including radar, direction-finding (DF) systems, and missile defense systems. Phase must be accurately controlled in the components within those systems, such as coaxial cables and connectors.
The concept of phase starts with the fact that a microwave signal propagates in the form of a sine wave. For every cycle of a sine wave, 360 degrees of electrical length is accumulated. If 50 cycles per second accumulate, it is a low frequency, with few cycles per unit of time, and a relatively long wavelength. At a higher frequency, millions or billions of cycles per second will accumulate, and the wavelengths are exponentially shorter.
Frequency, time delay, and physical properties including dielectric constant and propagation velocity all affect electrical length. Environmental factors are also very important, such as temperature fluctuations, flexure, handling, twisting, pulling, crushing and more.
Why Do Phase-Stable Assemblies Matter?
Phase-stable cable assemblies are important in today’s increasingly sophisticated electronic systems. In aerospace engineering and space technology applications, phased array antennas, synthetic aperture radars, and direction finding are all phase-sensitive uses. For example, electronically steered antennas use a variety of radiating elements, and then vary their phase relationships to control the radiation pattern, so they can switch from a search radiation pattern to a tracking radiation pattern or shift direction very quickly. All these elements are fed by transmission lines; beam accuracy depends upon the phase relationships between those cables. Phase is also responsible for precision in some of the more time-sensitive satellite applications like GPS systems, mobile cellular, military radar and more.
Specifying Phase-Stable Assemblies
There are two ways to spec a phase-stable cable assembly. One is to specify it in terms of an absolute quantity or to talk about it in relative terms. For the absolute electrical spec, you would determine that the cable assembly is 5,271 degrees +/- 1, for example. You can buy a cable and specify that as an absolute length in terms of time delay, 5.1 nanoseconds +/- 0.1, etc. It’s very convenient and easy. Then there’s the relative way of specifying cables, which is one cable assembly relative to another. Whether it’s 10,000 degrees or 20,000 degrees all that matters is the cables are the same electrical length within a specific tolerance.
As frequencies get higher and higher beyond the UHF frequency range, a million degrees can accumulate easily, making the absolute electrical length measurement a challenge. At high frequencies, tight tolerances and really short wavelengths, a relative measurement can be much more precise using a relative measurement.
Sometimes specs are requested that we think are impossible, but at Times, we roll up our sleeves and gather around the whiteboard to figure it out. What was impossible just a few years ago is typical today. And that’s going to continue: what is impossible today will be typical tomorrow.
To hear the full detail provided in the webinar, register now!

Outside the Box Solutions for Inside-the-box Applications: Webinar Summary
Summary
Technological advances across industries are leading to more complicated requirements for RF systems to accommodate higher frequencies, inside of devices that are continually getting smaller. Cabling for these systems is a challenge because in tight space configurations, traditional semi-rigid solutions have shortcomings. Using flexible cables that are specially designed to optimize space, bend around tight corners, and connect to various ports without wasted cable length is emerging as a preferred option. Durability and material selection are additional considerations as these cables are often used in challenging environments and applications like 5G, space and quantum computers.
This webinar details new and emerging solutions for RF interconnect systems that are easy to install, low maintenance, and cost-effective, enabling the latest, most advanced in-the-box applications. Watch the video or read the session notes below.
Session Notes
The higher frequencies demanded by today’s advanced RF and microwave communications—up to 110 GHz and beyond in some cases—require smaller equipment installations, densely packed with ever more technology. That means smaller cables that must fit into extremely tight spaces, with more interconnect requirements. Cabling from the front panel to the board becomes more complicated, leading to more difficult packaging challenges.
At the same time, RF systems are being used in many new places where they were never required before. As a result, environmental challenges are also becoming greater. It is a fairly complicated design problem: make the boxes smaller, put more into them, and ensure they survive in the most challenging places imaginable.
On top of that, 5G is also a rapidly growing technology; the small acronym covers a huge array of applications. One of them is the Internet of Things, which has made it economically viable to put radios on just about anything.
Moving Beyond Semi-Rigid: InstaBend™
Semi-rigid cables would traditionally be used for many of these applications; but in very small sizes, they become too fragile, making installation difficult as these types of assemblies are more prone to breakage. Semi-rigid is also more complex and time-consuming to manufacture because the cables must be bent to their final configuration at the factory.
One of the solutions that Times Microwave has developed to address this is InstaBend™. This product family is designed and assembled for extreme flexibility to fit into small spaces for interconnects between RF circuit cards, modules and enclosure panels. You want as much flexibility as possible when attempting to route cables tightly. InstaBend cable can be bent very closely behind the connector, saving space and simplifying cable routing.
The product family includes assemblies offered in two sizes: the InstaBend 047 and InstaBend 086. They are available in various lengths to make connections with minimum footprint. Connector types include SMP, SMA and 2.92 mm.
InstaBend is available within short lead times: standard configurations are stocked by many distributors, including DigiKey and Mouser, and custom configurations are available from Times Microwave with lead times of two to four weeks for the complete assembly.
TLMP Connectors
Times Microwave has also developed its TLMP (Times Locking Miniature Push-On), a unique miniature connector to address the common challenges with vibration and shielding compared to a traditional SMP.
TLMP connectors offer striking improvements over SMP connectors, and although they are miniature, they are rugged and durable to withstand harsh conditions. With highly dense connectors, making sure the interconnect is fully engaged is a challenge. TLMP connectors feature a locking mechanism that prevents possible de-mating during mechanical or vibration shock. Color indicators signify “positive locking” to quickly confirm proper installation—the coupling interface reveals a red band when unlocked and shows green when properly mated. This feature maintains the connector’s mate integrity even during extreme shock and vibration and prevents materials like fluids and gases from entering the interface.
When Semi-Rigid is Required
A flexible cable may not always work in extreme environments, so Times has also developed a new silicon dioxide semi-rigid cable that can withstand an incredibly broad range of temperatures from just above absolute zero up to 600oC and beyond. It is a very good low-loss cable, and it processes like a semi-rigid, but it can withstand temperatures, radiation, or just about any challenge.
Conclusion
Times Microwave designs robust and cutting-edge interconnect solutions to meet both electrical and environmental challenges outside and inside the box—and anywhere else you can imagine.
Q&A
Following are the questions that were asked by the audience:
- What is the lead time on the IB-047 and IB-086?
- What are the cables on the quantum computer image? Does Times Microwave make those?
To learn the answers and hear the full details provided in the webinar, register now!

Medical Applications: The Future of Healthcare Webinar Summary
Summary
RF technology is an increasingly important part of many new healthcare technologies that are making the hospitals of the future possible. For example, today’s healthcare providers are increasingly utilizing advanced medical diagnostic, imaging, and treatment systems, including computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound systems, to enable earlier detection of potential health conditions.
One element these systems have in common is that RF technology is used to power many of their critical functions. Medical electronics applications depend on high performance and reliability from components such as coaxial cables and connectors.
Watch the video or read the session notes below.
Session Notes
Medical advancements that depend on RF performance can be narrowed down into three main categories. These include electrosurgical devices such as lasers, robotic surgery, radiofrequency ablation (RFA), microwave ablation (MWA), and even cosmetic procedures. Secondly, MRI machines leverage RF pulses carried by coaxial cables, and other diagnostic imaging technologies. Infrastructure and connectivity are the third area focused on in this webinar; it includes critical communications aspects of hospital networks and an overlapping function with patient and equipment monitoring.
As healthcare innovations continue to advance, the underlying technology needed to support them must progress too. Medical electronics applications depend on high performance and reliability from components such as coaxial cables and connectors.
Ablation and Robotic Surgery
Electrosurgery uses radio frequency, specifically high frequency alternating current, to achieve thermal effects within biological tissue. An electrosurgical device unit (ESU) consists of a generator and a handpiece with one or more electrodes. Electrosurgical generators produce a variety of electrical waveforms. As these waveforms change, so do the corresponding tissue effects.
Two minimally invasive procedures that rely on RF technology are leading the way in electrosurgical treatments.
Radiofrequency ablation (RFA) and microwave ablation (MWA) use electrical and microwave energy to heat precision areas and destroy abnormal cells. The configuration of these life-saving machines requires coaxial cables in two critical places: within the generator itself and outside of it, connecting the external probes and catheters to the generator.
These require low-loss cables that are easy to install in tight and compact places. Furthermore, using a cable with a kink-free design is ideal for installations with numerous flexing twists and turns. Connecting the probes and catheters to the generator requires cables that are small, flexible, and nimble enough for the precise movements needed when performing procedures.
A sample application in this arena is the use of Times Microwave T-COM®-400 and StripFlex® SFT- 304 solutions to hook up the generators and their inner workings. These cables are easy to install in tight and compact places and their kink-free design makes them an ideal choice for installations with lots of flexing twists and turns.
The TFT family of cables were used in another application to connect electrosurgical probes and catheters to the generator. TFT cables are small, flexible and nime precise movements that doctors need.ble enough to accommodate th
Additionally, robotic-assisted treatments are now often performed along with RFA and MWA. Improvements in technologies such as virtual reality will bring more remote procedures as well. Cutting-edge custom coaxial cable solutions are often needed to power this, incorporating features such as low loss, high performance, precision, shielding, and flexibility.
MRI and Diagnostic Imaging
Times Microwave has a long history of supplying high-performance RF interconnect solutions to MRI manufacturers. MRI works on RF pulses carried by coaxial cables like Times’ high-power LMR® 900 and HP-1200 cables.
An MRI system must be well shielded to minimize interference with a healthcare facility’s communications networks and electronic systems. The MRI patient chamber is usually connected to signal and power sources in a separate, shielded room, interconnected by lengths of coaxial cable and connectors. These cables must send consistent signals between magnetized and ordinary environments with high-power demands. This can create challenging performance requirements for the coaxial interconnections.
While conventional corrugated cables meet low-loss specifications, they are difficult to install in the restricted spaces often found in MRI applications. Cable assemblies must therefore handle suitable signal power levels without distortion and with performance levels equipping them for extreme conditions (similar to the requirements of military electronics systems). These cables need to exhibit low loss and other electrical characteristics to support MRI system performance, along with mechanical properties that can simplify installation of the system and the cables within, such as incorporating a tight bend radius for fitting into small spaces.
Regarding other diagnostic imaging applications, there are two primary types of ultrasounds that also depend on high-performance RF interconnects: diagnostic, which most of us are familiar with, and therapeutic, a high-intensity focused ultrasound for therapy and medical procedures referred to as microwave diathermy.
Infrastructure and Connectivity
RFID is used in patient tracking and inventory management applications within a healthcare setting, as well as additional uses. An RFID tag consists of a tiny radio transponder, a radio receiver and a transmitter; it uses electromagnetic fields to automatically identify and track tags attached to objects.
Additionally, as the Internet of Things continues to grow, we will see many new and smaller wearable devices that will force RF cable diameters to get smaller and smaller. At the same time, the amount of data on networks will increase, and the addition of telehealth and internal health networks and hospitals will add to this demand.
5G
As the healthcare industry continues leveraging technical advancements, the communications technology powering them must also sufficiently advance to provide adequate bandwidth to support many simultaneous users, real-time video, large data transfers, and more.
5G wireless networks are now being rolled out to provide this much-needed bandwidth, at higher millimeter-wave frequency bands. For example, telemedicine requires a network that can support real-time high-quality video, which has traditionally required wired networks. With 5G however, healthcare systems can enable mobile networks to handle telemedicine visits, which has the potential to greatly increase their reach. 5G technology can also enable patients to get treatment sooner and have access to a wider variety of specialists. The technology can also increase remote monitoring offerings for healthcare systems since providers can be confident they will receive the data needed, in real time, to help provide excellent patient care.
5G will also enable the continued development of surgical robots and the networks supporting them. Many key healthcare functions are beginning to use artificial intelligence (AI) to determine potential diagnosis and decide on the best treatment plan for a specific patient. Additionally, AI can help predict which patients are more likely to have postoperative complications, allowing healthcare systems to provide early interventions when necessary.
Ultimately, by enabling these technologies through advanced communications networks, healthcare systems can improve the quality of care and patient experience, reduce costs, and more. But 5G demands a high level of interconnectivity – the frequencies can span from 24 GHz to 100 GHz, which is much higher than traditional wireless networks. As a result, RF performance and reliability are critical to support 5G.
Optimal coaxial cables for this environment require higher frequency, broad bandwidth, proven reliability, and low latency. Cable construction should also focus on high flexibility, low insertion loss and superior shielding. Times Microwave solutions for higher frequencies include LMR, MAXGAIN® and T-COM products.
Q&A
Following are some the questions that were asked by the audience:
- Is there an example of a medical application Times created that you could share?
- What are the cables on the quantum computer image? Does Times make those?
- What is the smallest cable that Times is currently making?
To learn the answers and hear the full detail provided in the webinar, register now!
Solutions for Low PIM Applications Webinar
Summary
This presentation, Solutions for Low PIM Applications, was originally delivered in August 2021 as part of Times Microwave Systems’ Times Talks webinar series. Following is a session summary of the talk given by Carrie Obedzinski, distributions sales manager for Times Microwave and Kevin Moyher, product manager for Times Microwave.
As the telecom industry moves to 5G, the need for small cell and DAS systems multiplies. Antenna densification required for 5G is creating a need for smaller and smaller, flexible, low PIM cables. As more 5G networks come online, demand for cabling solutions that can accommodate all the necessary connections in smaller, more compact installations, while minimizing PIM, will continue to grow. The webinar details how cabling solutions are designed at Times Microwave to meet these advanced requirements and enable the next frontier in telecommunications.
Watch the video or read the session notes below.
Session Notes
What is Low PIM? Why Does it Matter?
PIM is short for Passive Intermodulation, which is a type of distortion that may occur in passive, non-linear components such as RF cables and connectors. Essentially, when two or more frequencies exist on the same cable, there is a chance that a third frequency will form. Cables and connectors play a large role in PIM, which can occur because of something resistive in the interconnect, the junctions between different types of passive components such as the connector and cable, ferrous materials, inadequate tolerance, poor torquing, etc.
While PIM is an issue for almost every wireless system, it is more noticeable in cellular applications such as 5G because the frequency bands used are very close to each other. PIM can create interference that limits receive sensitivity, lowering the reliability, data rate, and capacity of the cellular system. This can also result in dropped calls.
PIM is also a great criteria for measuring the quality of an interconnect, especially mechanical integrity and VSWR (Voltage Standing Wave Ratio), which is a measure of return/insertion loss. In an ideal system, 100% of the energy is transmitted. However, if there is a cold solder joint or air pocket in the solder, loose connections or a related issue, the VSWR return or insertion loss may not be detected—but it will be picked up with passive intermodulation. This is another reason that carriers and integrators look for passive intermodulation.
What Can be Done to Minimize PIM?
First, ensure that the right materials and platings are used. Next, eliminate any nonlinear contacts within the RF interconnect, and any poor electrical contacts. This can be caused by loose parts, parts with rough surfaces, oxidation, residual flux, etc. If conductive material is used, particulate on the face of the dielectric or within the interface itself is going to cause a problem and may actually move directly on the connectors when installed.
What Type of Testing is Performed to Ensure Solid Performance?
In the telecom industry, it is pretty much standard to place two 20-watt signals on the RF interconnect. This is done to look at the third order harmonic, typically the harmonic of the largest magnitude. Most testing requirements are looking for 153 dBc-155 dBc or better. At Times Microwave, we look for 160 dBc or better.
There are two types of tests. The first is a static test, basically a bench test. If the right materials, and platings are used and the connectors are properly tightened, this is a fairly low bar to meet. The second test, a dynamic test, is much more difficult.
For example, IEC has a standard for placing cables into the connector interface. The cable is moved off center, creating tremendous stress on the electrical connection within that connector. If there are air pockets or loose connectors, it will also require tapping on the connector to break conductive particles that may be within an interface free. At Times Microwave, we perform 100% static and dynamic testing on all our RF interconnects. Next, we serialize the interconnects, and keep those tests curves on our website for access at a later time, and we also put that data right on the cables.
Times Microwave Standard Low PIM Portfolio
The Times Microwave standard low PIM cable portfolio includes the SPO™ low-loss, low PIM corrugated copper cable which is a workhorse in terms of low PIM interconnects. We also have a similar product in a fire-retardant version, SPF™. It is a UL listed, type CMR (riser). The durable fire retardant, low smoke polyolefin outer jacket is also suitable for outdoor use. Finally, there is the SPP™ for plenum requirements within a building. This is a UL listed, type CMP (plenum) that meets the standard tunnel test. All three products are available in 250, 375, and 500 sizes in any required connector configuration and length. They are also all 100% tested for static and dynamic PIM, VSWR and insertion loss with a serial marker band that includes test data.
5G and Small Cells Drive New Requirements
5G is driving densification of the network, and small cells are the solution to create this densification. The majority of 5G small cell applications are outdoors—installed around lamp poles, roof tops, telephone poles, etc. One thing that’s pretty common across all of these applications is that they require a lot of RF cable feeds, RF jumpers, jumper cables and feeder cables—in tight spaces. This creates challenging requirements, as the corrugated cables used in many low PIM applications are not the proper cables to make these tight bends.
Times Microwave TFT™ Assemblies
Times Microwave unique TFT™ or TFT™-5G flexible, low PIM, plenum rated jumper cable assemblies use a silver-plated copper flat braid outer conductor construction to create an ultra-flexible cable with a durable FEP outer jacket is suitable for both indoor and outdoor use. The TFT delivers the same VSWR and PIM performance as the helically corrugated SPO, SPS, and SPP in a much more flexible and rugged cable.
The quarter inch UL listed, type CMP (plenum) rated cable is available in 401 (similar to SPO-250 and SPP-250 and 402 versions). The 402 is a smaller diameter cable designed for tight places and smaller runs. TFT assemblies are also available in any required connector configuration and length, as well as 100% tested for static and dynamic PIM, VSWR and insertion loss with a serial marker band that includes test data.
Bundled, Multiport Cable Assemblies
The increasing demand for high coverage MIMO antennas used in 5G applications has led to substantial growth in the number of RF ports. Furthermore, 5G antennas are shrinking in size as higher frequency bands are used to accommodate larger bandwidth requirements, which translates into more antennas in a smaller space. This densification creates numerous challenges related to installation, torquing, ensuring proper weather sealing and more. Small cells are one application that is extremely well suited for a bundled cable solution.
Installation can be a time-consuming, labor-intensive, and logistical nightmare, creating the potential for cables to be the weakest link in the system. There are numerous variables to consider: is it the right cable or the right port? Is that connector properly terminated to that cable? Is the coupling properly torqued down? Is the whole thing properly weather sealed? Are those cables properly captivated? Are they hooked up to the right connector and port? Are they flapping around in the wind? Are they protected from the sun, or if not, do they have the proper UV resistance?
All of these concerns can be addressed by using a bundled cable assembly such as the new TMQ4Ô and TMQ5Ô bundled cable assemblies for 5G. This solution combines industry-standard four and five conductor MQ4/MQ5 connectors with Times Microwave’s high-end coaxial cables to greatly reduce the number of individual connections that must be hooked up while creating a more rugged solution. It checks off all the boxes in terms of antenna port densification, saving a lot of labor with quick and easy fool-proof installation. The entire TMQ4/TMQ5 bundle is sealed to IP-67 specification and features excellent UV resistance, adding to the assembly’s durability for long-term performance.
The most common bundled cable constructions are built with inner cables that are ¼” and smaller. This concept can be used on both non-low PIM and low PIM interconnects. There are a number of other constructions to address low PIM bundled harnesses, including corrugated copper outer sheaths as well as ultra-flexible flat braid constructions.
TMQ4 and TMQ5 also use a spring outer contact so that PIM performance is not tied to the how well the tip of the outer contact is making to its mate. These cluster connectors are keyed with a color code dot on the outer coupling nut to make engagement quick and easy.

FITS Shipboard Applications Webinar Summary- October 2020
Summary
This webinar details Times’ FITS connector system and its use in Naval shipboard applications. The FITS connector system is designed to introduce new levels of flexibility and durability in the most grueling environments. Tony Fedor explains how the system meets the latest military requirements to withstand any number of changing conditions. In addition, he covers the improved shielding capabilities and the overall versatility of the FITS connector system.
Watch the video or read the session notes below.
Session Notes
This webinar provides an overview of the Field Installable Termination Systems (FITS™) connector system in Navy shipboard applications. Many of these systems are connected using MIL-DTL-17 coaxial cables, the base specification for military approved coaxial cables. MIL-DTL-17 sets forth the parameters for cable materials, whether they are low- or high-temperature, fluoropolymers, braided materials, etc. It also includes requirements for testing parameters, including mechanical, physical, and environmental testing.
Cables and assemblies that are qualified to MIL-DTL-17 specifications are listed in the Qualified Products Database (QPD) by the Defense Logistics Agency (DLA). There are about 250 “slant sheets” currently in the MIL-DTL-17 (commonly referred to as M17) spec, and they are all completely different with their own set of electrical, physical, and mechanical parameters that set forth the design. Times Microwave Systems currently maintains more than 160 QPL listings, including high-temperature, low-temperature, armored versions, and many more.
Buyers should use caution when ordering products to meet the M17 spec: some manufacturers use vague terminology such as “M17-type,” “in accordance with M17,” “similar to,” or “equivalent to,” etc., that could lead to false representation. Those designators are not accepted under the current QPL status. For example, a product that states it is “similar to an M17” may fail fluid testing or might not quite meet the electrical characteristics for a broadband test. These issues could have a degradative affect in the performance of any RF system, especially within a military system.
Evolving MIL17 Standards
Back in 1993, there was a MIL standard 454 directive that moved to eliminate the use of PVC on ships. Earlier specs such as MIL-T 24 640, and 24 643 were multiconductor power and control specs that moved to low-smoke zero-halogen parameters. Revision G added requirements for shipboard cables, and a Type 14 crosslink polyolefin jacketing material. This introduced a new series of testing requirements for weathering, abrasion resistance, fluid immersions, heat distortions and a variety of other physical and mechanical properties.
Slant 180 through 200 incorporated direct replacements to RG cables. For instance, an M17 slant 75 is an RG 214 PVC jacketed cable that transitioned into M17-slant 190, a low-smoke zero-halogen version with the Type 14 jacketing, as well as additional features.
Slant 210 through 218 included “unswept” versions that test one discrete frequency many times at 400 MHz. This provides no guarantee of broadband performance, and many are starting to be inactivated for their swept counterparts.
That leads us to the latest specs, slant 220 through slant 229. Times Microwave LLSB®—a series of low loss, highly-shielded designs that provide better overall performance for attenuation and shielding compared to an M17 standard RG cable—fit into this. These are the latest, lowest-loss designs that have been added to the MIL-DTL 17 specification.
In addition to electrical performance, LLSB cables carry the same combustion requirements and testing of the type 14 jacket. So M17 RG and MIL17 slant 220 through 229 cables all meet combustion requirements including flame performance, acid gas, halogen content, smoke and toxicity levels.
The Perfect Mate: FITS Connectors
LLSB cables are fully QPL’d under the M17-DTL or MIL-DTL-220 through 229. To add to this, Times Microwave created FITSä, a Field Installable Termination System incorporating a series of connectors and tools to fit LLSB cables.
The big advantage of FITS is the excellent and consistent RF performance of the connectors. They are truly field-installable with ruggedized performance and a superior plating thickness. We have created DLA part numbers for 16 approved FITS connectors, with new ones coming.
FITS connectors use a bi-metal tin nickel plating. Traditionally, tri-metal plating (zinc, tin, and copper) was used and by comparison, the bi-metal plating performs extremely well in terms of corrosion, including excellent performance with the MIL-STD-810 requirement, or the salt fog test.

Beyond Teflon®: RF Assemblies for Extreme Environments
Summary
Beyond Teflon®: RF Assemblies for Extreme Environments, is part of our Times Talks webinar series.
Teflon® coaxial cables offer excellent performance, but every material has its limits. Learn how to specify the best, hermetically sealed, custom-designed cable assemblies that fit your system. Our team has helped hundreds of customers specify and qualify the correct SiO2 cable assembly for their applications.
Watch this webinar on-demand or read the session notes below.
Session Notes
Teflon is a phenomenal dielectric for microwave cables. It’s lightweight, low loss, and very flexible. However, even an excellent product has limits. Extreme environmental conditions are one for Teflon. For example, applications such as hypersonic missile guidance will reach temperatures ranging from 200-250°C, or even as high as 600-1,000°C. Teflon will simply melt in those conditions.
Second would be any application that requires strict phase stability. As discussed in our recent webinars on phase performance, the ability to match multiple microwave cables to each other so the signal takes the exact same amount of time to travel through, as well as controlling how that phase relationship changes over temperature, are absolutely essential properties in microwave cables used in applications like phased array radar.
A third extreme environment is high radiation, found in applications such as particle accelerators, where two beams smashing together generate a significant amount of radioactivity.
To address the challenges, Times Microwave has developed a proprietary silicon dioxide dielectric (SiO2) that excels in these environments. Silicon dioxide is used throughout the micro-electronics industry for its excellent insulating properties. The construction of the silicon dioxide coaxial cable starts with a solid oxygen-free copper center conductor, a silicon dioxide insulating dielectric, and stainless-steel jacket that has copper cladding to act as the outer conductor.
Silicon dioxide provides excellent phase stability and low hysteresis and can perform at extreme temperatures ranging from just above absolute zero to 1,000°C. The metal and silicon dioxide dielectric construction makes the cable resist radiation naturally, up to 100 mega rads. The stainless-steel jacket is welded to the connectors with laser beam technology to create a hermetic seal.
When specifying electrical performance for these cables, the first thing to think about is attenuation or insertion loss, which will depend on the cable size selected. Next, in terms of electrical length, it should be determined if the cables in the system need to be phase matched.
There are several ways Times Microwave can phase match cables, including relative or absolute value. A third option is to establish a golden standard—Times Microwave builds and tests one of the assemblies, and the data for all future assemblies is matched to the golden standard to ensure everything produced is the same.
In terms of power handling capacity, silicon dioxide is excellent in high power applications due to the nature of its construction. However, there are a few things that will decrease the power handling capacity of the cable. The first is VSWR; the higher the VSWR, the lower the power handling capacity. Second is altitude. If the application is operating in a vacuum, it will lose the natural convection that takes heat away from the cable, which will in turn reduce the maximum power that can flow through the cable. Finally, the operating frequency will determine what the power handling capacity of the cable can be.
Case Study: Climate Monitoring Satellite
Following is an example of a climate monitoring satellite application that required a set of electrical performance parameters that no other cables in the world could meet. It incorporates a space-based synthetic aperture radar to find sub-millimeter sized changes in the height of an ice cap to determine how much water is present.
From an RF perspective, extreme accuracy was required—any sort of error absolutely needed to be minimized, including the transmit and receive cables. All the different antenna cables had to be phase matched so the sensors could best understand exactly what they were seeing from the radar pulses. Temperature fluctuations also had to be addressed as a space-based application will go from warm on the day side of the planet to cold at night based on its orbit.
Other mechanical elements of the silicon dioxide cable that were relevant for this application included the stainless-steel jacket with a welded connector, designed to perform very well under high vibration environments such as during launch. It is also a non-outgassing material and is compliant for radiation considerations in an orbital environment. The third feature that will impact the mechanical configuration of the cable is the connector, which is application dependent.
Case Study: Hypersonic Missile Application
In this application, it was important to focus on the temperature capabilities of the silicon dioxide cable since a hypersonic missile will go through the top of the atmosphere, generating huge amounts of heat, similar to a space shuttle during re-entry.
As previously mentioned, the silicon dioxide cable itself can readily withstand those heat loads. But beyond that, one of the important requirements was phase matching at ambient temperatures. As the cable moves from cold temperatures to very hot temperatures, the phase matching between cables needs to track.
Furthermore, there are basic assumptions that likely have applied to many other specified cable assemblies that may not fit for extreme environments. For example, a shrink-down marker band that includes data such as the part number, serial number and manufacturer is a standard component in a bill of materials. However, at high temperatures, it is very likely that those marker bands will melt and create a potential foreign object debris hazard. The cable assemblies used in this application were laser marked to ensure that the important data was still included without creating any fault in the system while in operation. Custom connectors were also designed.

Medical Ablation Medical Design Outsourcing
Medical Ablation Medical Design Outsourcing
Microwave ablation systems provide nonsurgical methods for treating internal cancers and tumors. This application requires the right cable assemblies to achieve optimum performance.
How high-frequency interconnections affect microwave ablation systems
Radiofrequency (RF) and microwave energy carry many modern messages as part of the broadcast and wireless communications but are also potentially life-saving medical tools. Within ablation systems, radiofrequency and microwave energy can penetrate a patient’s body to heat and destroy tumors, avoiding invasive surgical procedures and long recuperation times.
These systems feature advanced software and artificial intelligence (AI) methods to treat tumors with minimal damage to surrounding tissues, but they still depend on many different types of RF/microwave components. This includes coaxial cable assemblies and often-invasive antennas formed of coaxial cables. The performance of these cables is crucial because life may depend on them.
How they work
Radiofrequency and microwave ablation systems use tiny antennas or probes projected onto a patient’s body to focus electromagnetic (EM) energy on tissues to be treated.
To reach malignant tissue with adequate EM energy, small-diameter coaxial cables are used to form finely polished antennas or probes and to transfer the EM energy from a source to the antenna. Those cables should provide performance levels that help RF and microwave ablation systems destroy the targeted malignant tissues. Shielded coaxial cables with low loss at the target frequency are typically used to preserve as much of the high-frequency source energy as possible; high loss in these interconnection cables will result in RF/microwave energy lost through heating the cables rather than heating the tumor.
How they differ
The smaller wavelengths and higher frequencies of microwave ablation systems allow deeper heating penetration and wider area heating coverage than radiofrequency ablation. Ablation systems typically operate in the ISM (industrial, scientific, medical) bands at frequencies of 915 MHz, 2.45 GHz and 5.80 GHz and at power levels of 50 W (+47 dBm) or more.
That EM energy is coupled to the antenna or probe by means of a low-loss coaxial cable assembly. Higher, millimeter-wave frequencies (through 60 and 70 GHz) have been used in ablation systems for special treatment, although the difficulty of generating EM power at these higher frequencies makes the component selection for those microwave ablation systems even more critical. That is, the energy loss of a coaxial cable increases with increasing frequency.
Cable considerations
The coaxial cables used in ablation systems and other high-frequency medical electronic systems are typically flexible cables capable of wide-band frequency coverage. They should be specified carefully according to parameters that can affect RF and microwave ablation system performance. Those parameters include loss/attenuation, phase stability, shielding, passive intermodulation (PIM) and velocity of propagation (VP).
Cable loss or attenuation is a function of its dielectric and conductive materials, diameter, length and the operating frequency. Loss increases with frequency and excessive loss can cause the temperatures of the cable and ablation antenna to rise, resulting in unwanted heating of tissues along the signal path to the antenna. In some cases, it may require some form of cooling to offset the cable temperature rise caused by handling too much power with too much loss/attenuation. Cable loss is typically characterized in dB/ft. It decreases with larger cable diameters, although they are less likely to reach a patient’s malignant tissue area.
Phase must be extremely stable along the EM power path in an RF or microwave ablation system to maintain a tightly focused energy beam on a malignant tissue. Multiple cables are used in phased arrays to create focused energy on the tumor. Phase deviations can occur with cable flexure and with temperature changes, which are usually measured and compared from cable to cable in terms of ppm/°C. Phase can also vary with impedance mismatches from a nominal 50 Ω, which are measured by variations in voltage standing wave ratio (VSWR) with frequency.
Other performance parameters include the effects of propagation delays and velocity of propagation through the cables, passive intermodulation and its impact on signal integrity, and shielding effectiveness, which describes how well a cable assembly is isolated from surrounding electrical devices and energy sources.
Shielding effectiveness is key because high energy levels could interfere with other systems using the same frequencies, such as WiFi.
RF and microwave ablation systems make huge differences in the health and lives of many patients. Coaxial cable assemblies are among the high-frequency components that make RFA and MWA systems possible. When they perform properly, they can be lifesavers.
The opinions expressed in this blog post are the author’s only and do not necessarily reflect those of Medical Design and Outsourcing or its employees.