RF circuit design of a multi-gap W-band sheet beam klystron

RF interaction circuits of a multi-gap W-band sheet beam klystron (WSBK), consisting of the input couplers, multi-gap bunching cavities and tapered output cavities were designed. All the circuits are employed for a 7.2mm×0.6mm (aspect ratio 12:1) sheet beam. The good performances such as E-field distribution, mode interval, R/Q and beam-wave coupling coefficient for a single and dual gaps quasi-optical (QO) input couplers, 1-5 gaps bunching cavities and 3-5 gaps QO output couplers were designed and presented by the HFSS and CST-MWS codes.