Generating High-Power Continuous-Frequency Tunable Sub-Terahertz Radiation from a Quasi-optical Gyrotron with Confocal Waveguide

To generate high-power continuous-frequency tunable sub-terahertz radiation, a quasi-optical confocal waveguide is attempted as the interaction structure of a gyrotron. In experiments, a gyrotron operated in quasi-optical TE06 mode generated a maximum output power of 20 kW when driven by a 50-kV, 3.4-A gyrating electron beam, and achieved a continuous-frequency tuning band of 205.66–208.97 GHz by adjusting the operating magnetic field. The design, experimental and particle-in-cell simulation results of this gyrotron are presented.