Coaxial Lightning Protection and Signal Quality Issues

Coaxial Lightning Protection and Signal Quality Issues

For wireless communication sites with antenna installations, a common issue of concern is whether adding an ethernet/ coaxial surge protector would lead to performance degradation within the system. The questions asked are whether it's actually worth considering? would it attenuate the incoming signal and distort quality? and where would it be placed in the installation? We will try to make a case for the need of coaxial surge protection and how to mitigate against the known drawbacks.

Browse an array of lightning protection devices (ethernet & coaxial) here and more content on the same in this link.



Coaxial Lightning Surge Protection Device

Here are some interesting SKUs for your consideration:

V-LP-N-P-BHJ Coaxial Lightning Protector, 0-7 GHz ,N-Female/N-Male Connectors, 20kA Rated Discharge for 8/20μS waveform

V-LP-N-J-BHJ Coaxial Lightning Protector, 0-7 GHz, N-Female/N-Female Bulkhead, 10kA Rated Discharge for 8/20μS waveform

TW-LP-RPSMA-P-BHJ Lightning Protector, 0-6 GHz, RPSMA-Male / RPSMA-BH-Female, 20kA Rated Discharge for 8/20μS waveform
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DGXZ+15TFTF-A Coax Lightning Protector, 800 MHz-2.5 GHz, TNC-Female/ TNC-Female, 20kA Rated Discharge for 8/20μS waveform

While it provides critical protection, there are some issues associated with coaxial lightning protection that can affect signal quality. Here are some of the key issues:
  1. Signal Loss: it can introduce some level of signal loss in the coaxial cable path. This loss is typically minimal but can become a concern in applications where signal strength is critical, such as in long cable runs or weak signal environments. 
  1. Frequency Dependence: In high-frequency applications, such as those used in broadband or wireless communications, the frequency dependence of the protection components can impact signal quality and introduce signal attenuation at specific frequency bands. 
  1. Insertion Loss: this is the reduction in signal strength as it passes through the protection device. This insertion loss is often expressed in decibels (dB) and can vary depending on the specific type and quality of the protection device used. 
  1. Mismatched Impedance: Improper installation or mismatched impedance between the lightning protection devices and the coaxial cable/ connectors can lead to signal reflections. These reflections cause standing waves, leading to further signal loss and potentially impacting the performance of the communication system. 
  1. Interference: In some cases, poorly designed or improperly installed lightning protection devices can act as unintended antennas, picking up electromagnetic interference (EMI) or radio frequency interference (RFI). This interference can couple into the coaxial cable and degrade the signal quality. 
  1. Grounding Issues: Effective grounding is critical for proper coaxial lightning protection. If the grounding system is inadequate or improperly installed, it can lead to ground loops, noise, or EMI issues, which may affect signal quality 
  1. Equipment Degradation over Time: Over time, environmental factors, such as exposure to weather conditions and corrosive agents, can degrade the performance of the lightning protection devices, potentially impacting their ability to provide optimal signal protection.

All these points raised can be easily handled by the following clear and concise considerations. As always, consulting with experienced professionals in the field will help you implement the best practices and ensure the reliability and performance of your installation. 



Ventev 0-7 GHz Lightning Arrestor (N-Female/N-Female Bulkhead)


Here are some of the considerations to be made: 
  1. Use high-quality, low-loss coaxial cables (600 and 400 series) and lightning protection devices: High-quality cables with low signal loss will help maintain signal integrity over long cable runs. Additionally, using reliable lightning protection devices specifically designed for coaxial systems will help divert lightning surges away from sensitive equipment.
  1. Ensure proper impedance matching: Impedance matching is critical in coaxial systems to prevent signal reflections and loss. All components in the system, including connectors and lightning protection devices, should have the correct impedance for seamless signal transmission. Typical impedances are 50 and 75 Ohms.
  1. Ground the lightning protection system effectively: Proper grounding is essential to provide a safe path for lightning surges to dissipate. A well-designed grounding system can help protect both the coaxial equipment and the overall communication system. 

Place the coaxial surge protection device near the point where the cable enters your building or equipment, close to the antenna.  It provides the shortest path for the surge to divert to the ground, minimizing the risk of damaging the connected equipment.

  1. Choose lightning protection devices with a wide frequency range: Lightning protection devices with a wide frequency range can offer better protection against transient surges across different frequency bands, reducing signal loss and potential damage to the equipment. 
  1. Conduct regular inspections and maintenance: Coaxial lightning protection systems should be regularly inspected and maintained to ensure their functionality and effectiveness over time. Environmental factors and wear can impact the system's performance, so periodic checks are crucial. 

For devices that use Gas Discharge Tubes (GDTs) these always have to be replaced after any significant strike.

In conclusion, we  recommend using coaxial lightning protection as a means to protect a communication system, especially when the system is exposed to outdoor environments and the risk of lightning strikes and electrical surges. They can significantly reduce the risk of equipment failure, data loss, and downtime due to lightning-induced damage.

Feel free to contact our Wireless Equipment Protection Specialists to help you design a suitable surge protection system for your outdoor wireless communication devices.

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