Theory of multi-beam stagger-tuned gyroklystrons

Summary form only given, as follows. Multi-beam configurations have long been used in linear beam klystrons. The use of a large number of beamlets propagating through individual channels allows one to significantly reduce the space charge effect leading to voltage depression. Therefore the total perveance of multi-beam klystrons is much larger than in single-beam klystrons. Correspondingly, these devices can produce a required power level at a much lower voltage and in a wider bandwidth. Recently, NRL has started the development of wide band high-power millimeter-wave gyroklystrons (GKLs) for radar applications. The present work is done within the frame of this program. In our paper we apply the multibeam concept to GKLs and analyze the possibilities of further increasing the bandwidth by stagger-tuning the eigenfrequencies of individual input cavities with respect to the signal frequency. The formalism describing the multi-beam stagger-tuned GKL is developed and the small-signal gain in two-stage, two-, three and four-beam GKLs is analyzed.