Design and Simulation of Coaxial Re-entrant cavities for Ka-Band Multibeam Klystron

This paper proposes a computer-aided design of Radio frequency cavities for Ka-band multibeam klystrons used in high gain and broadband operation. Coaxial re-entrant cavities have been designed and the number of beamlets for optimum performance has been investigated here. The simulation results show a 10-beam cavity with an R
SH
/Q value of ~ 90 exhibits an operating frequency near 27.78 GHz. The simulation tool, CST microwave studio is used to study the electromagnetic field distribution in the fundamental mode, shunt impedance and cavity frequency also.