Preliminary Experimental Verification of High Efficiency Q-Band Helix Traveling-Wave Tube

In this paper, a helix slow-wave structure (SWS) with variable pitch and inner diameter is designed for higher power, higher efficiency, and gain flatness in Q-band traveling-wave tube (TWT), and its device performance is studied by simulation and experiment. Here the helix of TWT is designed with a taper scheme. Under the conditions of beam voltage and beam current of 8.8 kV and 70 mA respectively, the preliminary experimental results show that the saturated output power of the TWT is about 80 W at 37 GHz and the saturated efficiency is about 44%. The output power of the TWT is about 20 W and the efficiency is about 17% when it is backed off 6 dB from the saturation. This research has laid the foundation for the next-generation wireless communication systems.