Design of a high-efficiency, broadband, second harmonic, 250 kW, Ka-Band amplifier

A theoretical design of a new broadband, Ka-band, microwave amplifier has been completed and is now presented. The device combines elements of traveling wave tubes and gyrotrons, producing a 5% instantaneous bandwidth and a 26-dB gain with a realistic beam. The amplifier is driven at the first harmonic near 17 GHz, and the output frequency is near 31 GHz. A linearly streaming angular beam (generated by a hollow Pierce-like electron gun) is bunched by a bells before being converted to a rotating beam in order to generate microwaves in a circular waveguide. Via this interaction, microwave energy is extracted with an efficiency above 42%. With an input beam voltage and current of 75 kV and 8 A, respectively, a peak power over 250 kW in the TE/sub 02/ mode is produced.