The numerical simulation of the radial coupling multi-cavity resonators

Broadband klystron is one of key devices in radar and communication system. The broadband performances of microwave output circuit play an important role for extending klystrons bandwidth. This paper describes the numerical results of a broadband output circuit-radial coupling multicavity circuit by using 3D electromagnetic field computation program, IS-FEL 3D, which includes the resonance performance, field distribution, mode construction and difference of radial with axial coupling multicavity circuit. The radial coupling multicavity circuit has been designed and manufactured, and the cold measurement shows that 7% bandwidth has been obtained.