Study on logarithmic dual gradient helix slow wave structure

In this paper, a novel logarithmic dual gradient helix slow wave structure (SWS) is proposed. Driven by a 6900 V, 50 mA pencil electron beam, the output power of the logarithmic dual gradient SWS circuit has been analyzed by the simulation tools. The maximum output power of the logarithmic dual gradient helix SWS circuit can reach 52 W. The output gain comes over 23.5 dB over 33~40 GHz. The electronic efficiency of the 50 mm long novel SWS circuit can be increased to more than 14%, which is a 50% improvement compared with the conventional helix SWS.