TRANSIENT SUPPRESSION IMPROVES RELIABILITY OF HIGH POWER AMPLIFIERS

Abstract

Intolerably high failure rates were experienced on a number of 1.8 G4z solid state amplifiers used in high power transmitters. Investigations revealed the existence of dangerously high transients on the DC power bus which extends from the power converter in the antenna pedestal to the amplifier located under the feed. Current and voltage requirements were such as to render commercially available transient suppressors, including zener diodes, ineffective. The problem was solved with a shunt regulator which normally draws no current, but effectively clips the transients.