ADAPTIVE HEATER VOLTAGE CONTROL AND MONITORING SYSTEMS AND METHOD FOR SETTING AND MAINTENING THE HEATER VOLTAGE OF A VACUUM ELECTRON DEVICE

摘要

An adaptive heater voltage algorithm and control system for setting and maintaining a vacuum electron device (VED) heater voltage, such as that of a klystron. An algorithm and control system are disclosed that sets and maintains the VED's cathode at the lowest temperature required for 98% of the beam current that corresponds to a fully space limited (FSCL) operation. VED lifetime is dependent upon cathode temperature, and in general, a cooler cathode will last longer. The optimum heater voltage corresponds to the beam current that is 98% of the beam current during FSCL operation. As the VED ages and the cathode becomes depleted, the heater voltage will need to be gradually increased to maintain 98% FSCL value. There are, therefore, two stages to the adaptive heater voltage algorithm - (1) initial determination of the heater voltage and (2) the determination of the heater voltage during amplifier operation.