Space Qualification of W-band Devices for the CloudSat Cloud Profiling Radar

The 94 GHz cloud profiling radar (CPR) instrument is on board the CloudSat spacecraft, launched in April, 2006. The radio frequency electronics subsystem (RFES) for this instrument consists of an up-converter, a receiver, and a transmitter calibrator assembly, which include W-band diodes (noise, Schottky and detector diodes) and MMIC amplifiers (LNA and MPA). W-band devices, in general, are not on the NASA parts selection list, and for most of them, CloudSat is their first use in a space application. Therefore, customized screening and qualification tests were developed for these devices, in order to insure high reliability to meet the 2 year CloudSat mission design life. High amplitude stability is also required for the noise source and transmitter power detector diodes, in order to provide accurate calibration of the overall cloud radar. The test approach and results are presented here