Lightweight traveling-wave tubes for space vehicles

The CW traveling-wave amplifiers recently developed for the power stage of the communications transmitters in the space vehicles of project SYNCOM (synchronous communications satellite) and project SURVEYOR (soft-landing lunar vehicle) are described. These tubes provide 2 watts to 20 watts of CW power in the 2.0 to 2.4 Gc telemetry band at a d-c to r-f conversion efficiency of 30% and a gain of 30 db. The tubes were especially designed from the outset for the space application; as such, high efficiency, minimum weight, and high reliability were optimized in the design. Metal-ceramic construction and periodic permanent magnet focusing are used for reliability and reduced weight. The basic tube plus magnets weighs 9 ounces. Overall weight of the tube and space package is less than 14 ounces, which is believed to be the lowest value so far achieved in a TWT at this frequency and power level.