Technological Breakthroughs in RF and Microwave Connectors Powering a New Era of High-Frequency Military Applications 

High-frequency military applications, operating in some of the world’s most severe environmental conditions, pose unique challenges. The mission-critical RF systems that underpin these applications, including satellite communications, electronic warfare, missile guidance, radar, and hypersonic systems, must operate flawlessly. To meet these demands, the ongoing evolution of hardware components and interconnect solutions is crucial, enabling them to withstand variable conditions, severe vibrations, and extreme temperatures.  

The performance of RF systems fundamentally depends on the integrity of hardware components and how they integrate. Innovations such as multiport connectors, locking miniature push-on, and blind mate connectors, offer superior environmental sealing and enhanced shielding compared to traditional designs, while ensuring mechanical retention in high-vibration environments. With the continual development of new high-frequency military applications that push the boundaries of power handling and performance, advanced connector designs help future-proof technology by accounting for the complex requirements of tomorrow’s applications.  

These advanced technologies usher in the modern era of reliable, high-performance military connectors that will thrive in demanding, variable, and extremely harsh environments.  

Establishing The New Industry Standard 

Legacy connector designs, such as SMP/SMPM, are no longer sufficient to meet the requirements of advancing high-frequency military technology. Susceptibility to electromagnetic interference (EMI) and electromagnetic compatibility (EMC), lack of environmental sealing, and the potential to disengage upon impact are some of the major issues of this design. These problems have spurred the development of innovative RF interconnects to address these challenges more effectively. 

Among these, locking miniature push-on and locking miniature blind mate connectors have emerged as the new industry standard. The rising popularity of these smaller-sized, O-ring sealed connector solutions surpasses their SMP/SMPM predecessors to deliver enhanced shielding, environmental protection, and mechanical retention. They are ideal for applications requiring an environmentally sealed and shielded connector or in high vibration environments, such as carrier landings or weapons launches.  

This modern class of connectors maintains the small form factor dimensions of SMPs while spanning a frequency range from DC to 60 GHz. The mating component effectively covers the connector’s slots, preventing signal leakage. This capability enables these connectors to effectively address performance challenges from EMI and EMC interference as well as minimize liquid and salt ingress. The sealed, rugged design enhances their resilience to withstand harsh conditions and severe environments. At the same time, the overlapping insulators cut off a direct path to the ground from the center conductor to the outer shield, enabling higher-voltage functionality. 

In addition, the connectors incorporate a latching mechanism, improving their mating retention capabilities and making them a more suitable choice than threaded body alternatives. A visual verification feature with red (unlocked) and green (locked) color coding provides visual confirmation that the connectors are fully mated and locked. The locking blind mate version is equipped with an additional outer sleeve, ensuring complete protection of tines for blind mate applications. 

Examples of these connector types include the Times Locking Miniature Push-On (TLMP) and the Times Locking Miniature Blind Mate (TLMB) connectors offered by Times Microwave Systems.  

Multiport Interconnect Systems Address Restricted Space Constraints and Rising Operating Frequencies 

RF system manufacturers continually create advanced designs to accommodate extremely restricted space constraints in military applications. While many critical systems operate in the 18 GHz range, newer ones are emerging that must work at 40 GHz.  

New multiport contacts allow equipment manufacturers to have a single connection that accommodates these frequencies. This contact type is compatible with existing multiport shells to maximize current infrastructure in high-frequency applications. Its unique construction makes this high-frequency contact excellent for the high-vibration, harsh environments typical in military and avionics applications. It also meets reduced size, weight, and power (SWaP) requirements.  

Multiport interconnect systems address the lack of electrical bonding and shielding that expose a conductor’s signal to external influence, which can create EMC and EMI issues in higher-frequency applications. They replace individual assemblies that require multitudes of connectors with an alternative solution featuring a single connection port.  

Fitting complex RF systems into tight spaces can create unwanted coupling between RF transmission lines, including coaxial cables. However, minimizing the distance between cables and connectors is required for the interconnect system to survive high vibration and other extreme environmental conditions. Multiport systems that integrate multiple coaxial contacts into a single housing for a higher interconnection density solve this problem. This simplifies system maintenance and testing, reduces installation time, and increases reliability. 

Higher Power: Trusted Designs Enable the Next Leap Forward  

As harsh environment applications continue to advance, the need for new connector solutions for high-density, high-power applications also grows. For example, locking miniature push-on and blind mate connectors are evolving to accommodate higher CW power and frequencies above 18 GHz. 

These connector types are critical to ensuring the reliability of high-frequency military communication systems. They are well-suited for a wide range of applications, including densely packed signal intelligence and electronic warfare systems. While these connectors preserve the previously mentioned attributes, including the overlapping design, environmental sealing, and enhanced EMI performance, they also incorporate new capabilities to manage high power at altitude efficiently. 

The Times Locking Connector (TLC) is an example of technological advancement in this field. It was engineered with a 40-mil line size design and built to handle higher transmit powers aboard aircraft. This connector utilizes dielectric materials to strengthen its thermal, making it specifically tailored for effective heat dissipation of high continuous wave (CW) power at higher altitudes. It is exceptionally well-suited for applications up to 23 GHz. 

When the TLC connector design is too large for a particular system, alternative technologies like the Times Locking Push-on Connector (TLPC) manage high power levels while maintaining a considerably smaller form factor. It features a 30-mil line size and is available in multiple versions, including card edge and various edge launch configurations. It is designed for easy integration, whether threading through the wall of a box or soldering to the ground plane and the center pin or trace on the board, making it suitable for applications requiring a frequency range of up to 32 GHz. 

The innovative connector designs detailed above go beyond single interconnects and can be incorporated into multi-ported versions, eliminating conventional coupling nut schemes to enhance space utilization and operational efficiency. In this configuration, the interfaces are integrated into male and female shells, effectively serving as bulkhead disconnects, enabling significantly higher interface densities. 

Precision Manufacturing Execution Requires Collaborative Partnerships 

The use of acceptable materials and Mil-spec constructions are mandated to meet the stringent technical standards required for products deployed in military environments. However, there is not a universally applicable standard for applying these materials to construct a consistently reliable RF solution.  

Collaborating with an experienced supplier with access to a comprehensive range of product options, deep expertise, and a trusted heritage of engineering development in mission-critical industries is paramount. The chosen partner must thoroughly understand material technologies and possess in-depth knowledge of the specific applications, environmental factors, and underlying physics.  

Furthermore, the RF supplier should act as an integrated extension of the project’s design team. Given the highly complex nature of high-frequency military applications, which rarely incorporate standardized solutions, the technical team must ask the right questions to gain insight into the application’s unique requirements. Additionally, the supplier should assist you in understanding the electrical and mechanical trade-offs specific to your application. This collaborative effort is instrumental in creating modern, reliable solutions that offer superior electrical, mechanical, and environmental performance. 

While evaluating a supplier’s manufacturing operations, it is important to keep several key qualifications in mind. Robust facilities and well-defined processes can help ensure seamless execution. Cleanroom manufacturing capabilities and traceability in managing all the parts that make complicated assemblies are essential. It is also important to know which quality standards the supplier adheres to and any extended services offered. In an ideal scenario, the RF supplier possesses the full spectrum of technology and products required and understands how to integrate them into a finished product. 

In Summary 

RF and microwave connectors are critical in ensuring the integrity and reliability of high-frequency military communication systems. Evolving connector designs offer substantial reductions in physical footprint, available in single-mount or multi-ported versions, to support higher densities and power thresholds of modern applications while solving the EMI and environmental issues of the previous generation of RF connectors. These advanced designs are ushering in a new era of consistently high performance, even in the most demanding, variable, and extremely harsh environments.