Beam Wave Interaction Simulation of a 220 GHz Non-Periodic Folded Waveguide Slow-Wave Structure TWT*

Based on phase velocity synchronization theory, a concentric arc FW-SWS is designed for 220 GHz TWT. Based on the unique advantages of concentric arc SWS, such as strong beam wave coupling, low synchronous voltage, high efficiency and effective clutter oscillation suppression, CST Particle Studio software is used to continuously optimize the SWS and adjust the beam wave interaction parameters, and try to make a breakthrough in output characteristics of this structure as slow-wave circuit of TWT. The simulation results show that the maximum output power, gain and electron efficiency are 112.82 W, 20.61 dB and 10.27%, respectively, when the electron beam voltage is 15.7 kV, the current is 70 mA and the SWS is 99 units.