Initial operation of a wideband 140 GHz, 1kW confocal gyro-traveling wave amplifier

The initial experimental results of a zero-drive stable, short pulse 140 GHz gyro-traveling wave tube amplifier are presented. The amplifier has achieved a linear gain of 31 dB in experiment, and peak output powers up to 400 W have been observed at a beam voltage of 39.5 kV, beam current of 1.65 A, and beam pitch factor of 0.9 from a novel high order HE(0,6) operating mode of a quasi-optical confocal waveguide.