Dielectric-lined azimuthally periodic circular waveguide for Ka-band TWT

The electron beam interaction in a novel slow-wave structure called dielectric-lined azimuthally periodic circular waveguide (DLAP-CW) is studied in Ka-band frame, which is a modified form of a conventional dielectric-lined circular waveguide (DL-CW). And the DLAP-CW has large beam aperture, good dispersion characteristics and easy fabrication. In this paper, the capability of beam-wave interaction when the DLAP-CW TWT operates in Ka-band is researched by CST PIC-solver. The particle-in-cell simulation results show that more than 1200W output power can be produced in DLAP-CW TWT interacting with high current annular beam with a low electron density 1.8 A/cm². Furthermore, the gain at the central frequency of 30 GHz reaches 31 dB.