70% efficient Ku-band and C-band TWTs for satellite downlinks

For traveling wave tube (TWT) amplifiers which transmit downlink signals from both geo-synchronous satellites and deep-space spacecraft, the single most important attribute continues to be overall dc-to-RF conversion efficiency. Currently, the most popular satellite downlink bands are 3.4 to 4.2 GHz and 10.9 to 12.75 GHz. This paper discusses recent production TWTs at L-3 Communications Electron Technologies, Inc., which are achieving dc-to-rf efficiencies of over 70% at power levels ranging from 65 to 150 W in these high-demand satellite downlink frequency bands. These TWTs continue to provide a large advantage over the use of equivalent solid-state power amplifiers.