The Application of Saturable Magnetics in the EMP Protection of High Power, RF Transmitters

Abstract

A unique and innovative all solid state, self recovery HESA design concept was developed for Kilowatt RMS level, RF transmitters using existing metal oxide varistor and saturable magnetic device technologies. This design concept, which is based on a two element hybrid protective device approach, has the dual capability to provide high voltage/fast rise time and long pulse/high current threat protection. The first element provides delay-free protection against the fast rise time HEMP threat and was implemented using metal oxide varistor technology which General Electric developed. The second element provides the high energy relief for the first element, and was implemented using saturable magnetics. Detailed magnetic device and varistor models and analytical design equations were derived and extensive material characteristics were experimentally obtained in support of this development. Much of this work involved the generation of singular information which was required to support the solutions to the design problems encountered in meeting the design challenge using existing materials technology. This paper addresses the saturable magnetics portion of this work.