A two-level, high-power, air cooled traveling-wave tube for communication systems

A two-level 600/1200 watt CW, X-band, coupled cavity traveling-wave tube featuring low distortion characteristics and air cooling enhanced by the use of heat pipes is described in this paper. This lightweight tube was developed for military communication ground terminals, under the sponsorship of the U.S. Army Electronics Command, Fort Monmouth, New Jersey. The tube is PPM focused and incorporates heat pipes on the RF circuit to uniformly distribute the relatively high thermal loads and ensure reliable air cooling. The tube provides either 600 or 1200 watts of saturated CW output power over the frequency band 7.9 to 8.4 GHz. Two levels of saturation are achieved by varying the voltage on an isolated anode, which increases the effective perveance of the electron gun. Gain variations of less than 1. 2 dB have been achieved across the 500 MHz band.