High power, high efficiency 32 GHz space traveling wave tube

Boeing Electron Dynamic Devices, Inc. in collaboration with NASA Glenn Research Center, has demonstrated 100 W CW and 60% overall efficiency at 32 GHz in a TWT designed for deep space communications applications. Additionally, the TWT is designed to allow for variable output power levels, from 50 to 150 W, depending on mission requirements. The Boeing 999H is a helix TWT with PPM focusing in a conduction-cooled package. The electron gun is a dual anode, isolated focus electrode design, and is designed for greater than 12 years of mission life. The helix circuit is designed to provide near constant efficiency and gain over the 31.8-32.3 GHz band, while maintaining high linearity performance. Improved beam focusing reduces the thermal load on the helix, and increases the BWO margin. The four- stage, depressed collector has been optimized for flexible power requirements and reduced backstreaming.