Rundown of Key Considerations of RF Surge Protectors for Telecommunications

Coaxial RF surge protectors, or lightning arresters/surge suppressors, are important components that help protect sensitive radio and sensing electronics with external components or cabling from electromagnetic pulse (EMP) or other types of electrical surges. The basic function of these components is to short the transmission line to ground in the case of surge that exceeds specified input power while allowing for unimpeded operation of and passing of desired signals.

Typically, coaxial RF surge protectors are made as inline coaxial components with either male or female coaxial connectors. Some RF surge protectors are designed as bulkhead fixtures that can be used to protect an assembly or housing from EMP or other surges, while others can be installed inline or with brackets to exterior surfaces.

Common RF Surge Protector Connector Types
• N-type
• DIN 7/16
• TNC
• 4.3-10

Coaxial RF surge protectors typically come with coaxial connectors that are commonly used for telecommunications applications, as telecom installations are often outdoors or in areas where EMP/surges from lightning or electrical systems are possible. The coaxial connector gender can be the same or mixed depending on the particular component, and may be used in place of an adapter if a gender change is required.

Key RF Surge Protector Parameters
• Directionality
• Multi-strike capability
• Frequency Range
• Surge Current
• DC Handling
• Maximum Power Handling
• Connectorization
• VSWR
• Insertion Loss
• Return Loss
• Turn-on-voltage
• Maximum Voltage
• PIM
• Environmental Resistance Rating (IP rating)
• Compliance
• Turn-on time
• Impedance

The performance of a surge protector is much the same as any inline RF component, with the exception of the surge suppressing features. Hence, performance parameters, such as VSWR, insertion loss, impedance, return loss, and frequency range of operation are all critical features. Unlike adapters, however, the frequency range of RF surge protectors is limited by the surge suppression technology and not the connector type or design. Moreover, some RF surge protectors are also unidirectional, unlike adapters which are always bidirectional.

Also, RF surge protectors may be DC-pass or DC-blocking depending upon the design. In the case of DC block surge protectors, the actual lower cutoff frequency may be a few megahertz to a few hundred megahertz. DC pass RF surge protectors may also have a frequency of operation well above DC if that is the region where the specified performance is achieved.

Key RF surge protection parameters are the total power handling, surge current, turn-on-voltage, maximum voltage, and multi-strike capability. In some cases, such as with PIM sensitive applications, the PIM performance of a RF surge protector is also a key consideration. This is where there are now low-PIM RF surge protector models that cover all common cellular frequencies. As many RF surge protectors are also installed outdoors, environmental ruggedness ratings are also important, of which IP67 is common.

Learn more about Pasternack’s line of RF Surge Protectors here: https://www.pasternack.com/nsearch.aspx?Category=Surge+Protectors&sort=y&view_type=grid