Analysis of high-order mode self-oscillation in an oversized coaxial relativistic Klystron amplifier at Ka band

In this paper, we analyze the mode excitation of the oversized coaxial resonant cavity and the high- order mode self-oscillation in an oversized coaxial relativistic klystron amplifier at Ka band. The high-order mode self- oscillation is studied by using the particle in cell simulation. The simulation results show that the excited mode of the input cavity results in the high-order mode oscillation in the oversized coaxial relativistic klystron amplifier.