Analysis of a frequency-modulated reflex klystron with minimum incidental amplitude modulation

Simultaneous modulation of the reflector and beam voltages of a reflex klystron will produce frequency modulation with minimum incidental amplitude modulation. The required variation of reflector voltage with beam voltage, for constant output power, is derived from the fundamental equations of the reflex klystron. Experimental verification of this analysis is presented. Reflex klystron oscillators which can be frequency modulated with minimum incidental amplitude modulation find application in FM Doppler radars, communications systems, and as signal sources for microwave testing.