Analysis and simulation for double reentrant cavity of multiple-beam klystron

An analysis method used for the double reentrant cavity of multiple-beam klystron is developed in this paper. According to the field equivalent principle, the equivalent model cavity is divided into two regular regions. The field of each region is stimulated by virtual surface magnetic current density on the common surface and ca n be expressed by integral of Green functions. The resonant frequency can be obtained by solving the field matching equation. With the HFSS field computation co de, the theoretical result is compared with the simulation one.