A 200W 92-98GHz Continuous Wave Traveling Wave Tube

In this letter, a 200 W 92–98 GHz continuous wave (CW) traveling wave tube (TWT) is designed. The electron gun generates a beam current of 173 mA at a beam voltage of 21.75 kV and the beam fill factor is 0.64. The fluctuation radius of the electron beam is less than 0.2 mm under the effect of a periodic permanent magnet (PPM) focusing system with a peak magnetic field of 0.51 T. The slow wave structure (SWS) uses a non-circular bent folded waveguide (FWG) structure with large beam tunnel to obtain high beam transmission rate. The high frequency system adopts a three-stage design to effectively suppress oscillations. Additionally, phase velocity tapering technology is integrated into the tube design to enhance electronic efficiency. The experimental results demonstrate that, at a transmission rate of 99.1%, the TWT achieves a maximum output power of 54.2 dBm at 94 GHz, with a corresponding gain of 42.4 dB. The proposed design significantly enhances electronic efficiency, suppresses oscillations, and considerably increases output power.