Staggered Double Vane Traveling Wave Tube Amplifier (sdvtwtas) with Multi-Staged Phase Velocity Matching

The electron beam co-propagating with slow waves in a staggered double vane array (SDVA) efficiently amplifies millimeter and sub-millimeter waves over a wide spectrum. Our theoretical and numerical analyses show that the power amplification in the fundamental passband is enhanced by the extended beam-wave phase-matching. Particle-in-cell (PIC) simulations on the SDVA slow wave structure, designed with 10.4 keV and 50 - 100 mA sheet beam, indicate that maintaining beam-wave synchronization along the entire length of the circuit improves the gain by 7.3 % leading to a total gain of 28 dB, corresponding to 62 Watts saturated power at middle of operating band, and a 3-dB bandwidth of 7 GHz with 10.5 % at V-band (73.5 GHz center frequency) with saturated peak power reaching 80 watts and 28 dB at 71GHz. These results also show a reasonably good agreement with analytic calculations based on linear gain theory.