Practical Approach for High Current Radome Testing

EM-transparent radomes constructed from dielectric material offer no EM screening of radomes to the external EM fields associated with lightning strikes. The antenna structure presents a major electrical stress raiser and is a likely target of a lightning strike. Therefore, a lightning protection system is to be designed to prevent lightning flashes from puncturing the radome and from damaging the antennareceiver system. High voltage (HV) testing that reproduces the lightning phase of the bidirectional leader development generally proves the functionality of the lightning protection system. However,discharge currents from HV generators do not exceed a few kA, so the ability of the protection system to divert and withstand the high current load cannot be demonstrated. The necessary experimental procedures for high current (HC) tests on coupons of the radomestructure with the diverter strips mounted in a representative manner are discussed in the following. Moreover, successful HC test results for a generic Satcom A-Sandwich radome structure are presented.