W-band phase-velocity-taper Traveling Wave Tube based on sine waveguide

A W-band phase-velocity-taper Sine waveguide traveling wave tube (TWT) with sheet electron beam is proposed to amplify the millimeter wave. In this paper, the high frequency characteristics of sine waveguide with sheet electron beam tunnel are simulated by 3-D high frequency simulation software. The simulation results also show that the tube with phase taper structure can produce over 235W output power and 32dB gain at typical frequency 94GHz with an operating voltage of 20.3 kV, a current of 0.2A, and an input power of 150mW. The corresponding gain is more than30dB from 90GHz to 100GHz. The particle-in-cell simulation results indicate that the phase-velocity-tapered sine waveguide structure can increase the output power 46% at 94 GHz.