Moderate-Power W-Band Cerenkov Traveling-Wave Amplifier

A compact W-band (95 GHz) traveling-wave amplifier design is discussed, in which the slow wave circuit consists of a smooth rectangular waveguide with ceramic dielectric lined side walls. Small-signal performance for the 15-kV, 0.33-A device is predicted to include 30-dB gain for a 7.4-cm long circuit, ~500 W output, 2 GHz instantaneous bandwidth, and 13 GHz voltage-tunable bandwidth. A 2-3 kG solenoidal magnetic field is required for beam focusing. Rectangular geometry for the slow wave circuit allows for longitudinal splitting of the circuit, thus permitting precision fabrication and suppression of non-symmetric competing modes.