A Coupled Resonator Reflex Klystron

737 739 742 746 746 748 750 750 752 754 757 760 762 764 765 The conventional reflex klystron derives its performance characteristics from the interaction between the electronic admittance due to a bunched electron stream and the input admittance of a resonant cavity. As is well known, this interaction results in mode shapes which are closely related to certain input properties of the passive resonant circuit. Thus, the dependence of power output upon frquency, which results from variations in repeller voltage about its mid-mode value, bears close resemblance to the input-impedance-versus-frequency plot of a parallel resonant circuit. Similarly, the curve relating frequency to repeller voltage has the same general shape as that relating frequency to the input phase angle of the resonator. Recognition of these relationships has resulted in the consideration of different and, perhaps, more useful mode shapes which might be obtained if the electronic admittance were made to interact with impedance or admittance functions of passive circuits other than that due to a single resonator. What do we mean by "more useful" mode shapes? The answer, of course, depends on the application, although an "ideal" mode shape could probably be defined as one having a flat top, i.e., power output inde-