COUPLED CAVITY SLOW WAVE CIRCUIT FOR MICROWAVE TUBES

摘要

A coupled cavity slow wave circuit and microwave tube using same are disclosed. The coupled cavity slow wave circuit includes an array of cavity resonators coupled together via the intermediary of an array of slots communicating through the common walls of adjacent resonators. The slots are dimensioned to have a resonance frequency substantially at the upper band edge frequency of the cavity passband mode such that the higher frequency passband of the slot mode is coalesced with the lower passband of the cavity mode. The coupling slots are arranged in an array such that the centers of the coupling slots in opposite end walls of the coupled cavities are aligned in axial direction of the slow wave circuit along a line which is generally parallel to the axis of the same beam. This in-line slot configuration allows higher interaction impedance in the 1.5 pi to 1.8 pi radians of phase shift per cavity period without band edge instability.