Development of a brazed-helix TWT for future Ka-band earth stations delivering 200 W in the band 27.5-30 GHz

The development of a family of brazed helix CW TWTs (continuous wave traveling wave tubes) operating in the 27.5-30-GHz frequency band is described. Results are given for a 200-W model now in the final stages of development, along with a description of the main technological choices and operating parameters. Power levels of 180 W CW have been obtained from a breadboard model, and 200 W will be easily obtained by minor adjustments to helix geometry. Destined for uplink earth station amplifiers in satellite communications applications, this tube has been optimized to meet the needs of civilian equipment users, offering high performance, low cost, high reliability, and long life expectancy. Preliminary tests confirm that the TWTs meet these criteria.<>