Transmission effects of surge protectors on category-5 cable systems

Surge protectors may be used on paired-conductor telecom circuits to provide protection against unwanted electrical energy surges. These protectors may have capacitance, inductance, or series resistance that can affect transmission. This paper provides numerical analyses of voltage-limiting and current-limiting protectors insofar as they impact insertion loss, return loss, and timing on a category-5 circuit. It is shown that surge protectors can significantly degrade transmission unless they are selected to be compatible with high-frequency applications by minimizing capacitance of voltage limiters, and series impedance of current limiters.