Design and Simulation of 220GHz Folded Waveguide Traveling Wave Tube

A folded waveguide(FW) slow wave structure(SWS) of a traveling wave tube(TWT) operating at 220 GHz is designed in this paper. Phase Velocity Tapering(PVT) is used to improve the efficiency of the beam-wave interaction, aiming to achieve higher output power. Additionally, the loss of electromagnetic waves is considered. A stable output power of 148.6W is obtained with a 23.8kV, 80mA electron beam, the gain is 34.7dB, and the 3-dB bandwidth is 8GHz.