Abstract :
The possibility of improving the performance of swept-frequency reflex klystrons is investigated. For this purpose, constant output power curves, as a function of resonator and reflector voltages, are derived, the corresponding frequency change being also calculated; the experimental verification of these curves is given, showing good agreement with theory. After ascertaining the character of the derived curves, a method for obtaining a swept-frequency output from a reflex klystron, at a constant power level, is proposed. This method consists of simultaneously varying the reflector and resonator voltages by means of a feedback network. The design of such a circuit is discussed, showing the possibility of adaptation to any reflex klystron, without any internal changes in the tube. Finally, the performance of an experimental X-band swept-frequency oscillator is described. This instrument is capable of delivering an output power, constant to within 1%, while swept over a 70 Mc/s band, at any centre frequency in the working range of the klystron.
