W-Band 1-kW Staggered Double-Vane Traveling-Wave Tube

A design study for a W-band traveling-wave tube (TWT) using a staggered double-vane slow-wave structure combined with a sheet electron beam shows that an output power of over 1 kW should be possible. Numerical eigenmode calculations indicated that the structure has a strong longitudinal component of electric field for interaction with the electron beam. A novel input and output coupler was proposed that can produce good input and output matches. Finally, a TWT model with moderate dimensions was established. The particle-in-cell simulation results revealed that the tube can be expected to produce over 1 kW of peak power in the range from 90 to 95 GHz, assuming an RF input signal with a peak power of 0.15 W and a beam power of 10.3 kW. The corresponding conversion efficiency values vary from 9.87% to 12.15%, and the maximum gain is 39.2 dB at 93 GHz.