Comparison of solid state, MPM, and TWT based transmitters for spaceborne applications

This study compares current and projected state-of-the-art microwave power amplifiers used in spaceborne transmitter technologies at frequencies through 100 GHz. Projected are future trends in power PHEMTs and in wide bandgap semiconductor devices such as GaN and SiC. Also, the more established InP HEMT low-noise devices are examined for possible power amp applications specifically in the millimeter wave region. Three key power amplifier technologies, including the traveling wave tube amplifier (TWTA), the solid state power amplifier (SSPA), and the microwave power module (MPM), have emerged in varying degrees as heritaged and/or viable components in spaceborne transmitters. Addressed as figures of merit are significant discriminators such as long term reliability, space heritage (failure-free on orbit performance), process/device maturity, size, weight, and efficiency.