Low distortion TWT design for space applications

The simultaneous amplification of multiple carrier signals is an important aspect of efficient space communication. In space-ground transmission links, the transmitting amplifier must therefore exhibit both high conversion efficiency as well as low distortion. Two significant types of distortion which tend to decrease the transmission channel efficiency are crosstalk and intermodulation distortion. Both space telemetry and tracking systems, as well as communication satellites, benefit from improvements in this area. In this paper, the results of an experimental study program are described in which the objective was to determine those factors which maximize the distortion-efficiency product of a traveling-wave tube amplifier. The simultaneous amplification of two phase-modulated carriers was studied as a function of tube design and signal parameters.