Editing Surge protector (section)

=== Quarter-wave coaxial surge arrestor ===
[[File:EMP protector - quarter-wave shorting stub.jpg|thumb|Quarter-wave coaxial surge arrestor]]
Used in RF signal transmission paths, this technology features a tuned quarter-wavelength short-circuit stub that allows it to pass a bandwidth of frequencies, but presents a short to any other signals, especially down towards DC. The passbands can be narrowband (about ±5% to ±10% bandwidth) or wideband (above ±25% to ±50% bandwidth). Quarter-wave coax surge arrestors have coaxial terminals, compatible with common coax cable connectors (especially [[N connector|N]] or [[RF connector#Standard types|7-16]] types). They provide the most rugged available protection for RF signals above {{nowrap|400 MHz}}; at these frequencies they can perform much better than the gas discharge cells typically used in the universal/broadband coax surge arrestors. Quarter-wave arrestors are useful for [[telecommunications]] applications, such as [[Wi-Fi]] at 2.4 or {{nowrap|5 GHz}} but less useful for TV/[[CATV]] frequencies. Since a quarter-wave arrestor shorts out the line for low frequencies, it is not compatible with systems which send DC power for a [[Block converter|LNB]] up the coaxial downlink.