Design of a Novel High Power Octagonal Ring-Bar Traveling-Wave Tube

In this paper, an octagonal ring-bar slow wave structure (SWS) traveling-wave tube (TWT) operating in the Ka-band with high power and low gain fluctuation is presented. This SWS is designed as an octagonal where supported by four dielectric support rods. The electromagnetic characteristics and the beam-wave interaction of this structure are investigated by CST software and the simulation results show that this SWS can produce over 1kW average output power in a frequency range from 29 GHz to 34 GHz when the operating voltage and beam current are set to be 13.9kV and 0.7A respectively, and the corresponding conversion gain values vary from 45 to 47.6dB within this bandwidth.