Times Protect Grounding and Lighting Brochure

This paper examines the characteristics of cloud-to-earth lightning strikes and the resulting probability of damage to existing wireless infrastructure. Wireless networks often rely on tall communication towers, which have a high likelihood of being struck by lightning. With over 2,000 thunderstorms active worldwide at any moment, producing around 100 lightning flashes per second, the risk is significant. As society becomes more dependent on computers and communications networks, protection from system disruptions due to lightning becomes essential.

Protection Techniques for Equipment Connected to the Antenna Feeder Cable

The coaxial antenna feeder cable is a primary source of damaging lightning energy to equipment at a communications site. When struck by lightning, the tower acts like a voltage divider, creating a high peak voltage at the top relative to zero voltage at the base for a few nanoseconds. Current then flows through the tower and all attached conductors.

If the bottom coaxial cable ground kit is elevated above the earth, the overall inductance can cause a substantial peak voltage. This voltage on the coax shield drives current to the equipment, grounding through the equipment chassis.

Why Are Coaxial Cable Lightning Protectors Required?

During a lightning strike, a potential difference arises between the coaxial cable shield and the center conductor at the equipment end of the cable. While a coaxial cable efficiently transfers RF energy with minimal losses at the operating frequency, it attenuates higher frequencies over extended lengths, effectively acting as a low-pass filter. Understanding these parameters is crucial for analyzing and mitigating lightning impact on wireless infrastructure.