A 20W GaN-on-Si Solid State Power Amplifier for Q-band Space Communication Systems

This contribution presents a Q-band Solid State Power Amplifier developed for next generation High Throughput Satellite (HTS). The Radio Frequency Tray (RFT) is composed by the cascade of a channel amplifier, a linearizer and a high power section. The first two sub-units are built with mainly Gallium Arsenide components, whereas the latter combines sixteen elementary MMICs Power Amplifiers (PAs), designed ad-hoc on a commercial 100nm gate length Gallium Nitride on Silicon (GaN-Si) process, in WR-22 waveguide structure. In the overall Q-band downlink range (i.e., from 37.5 to 42.5GHz) the SSPA delivers more than 20W of output power with an associated Noise to Power Ratio and power added efficiency better than 18dB and 15%, respectively, whereas the gain can be varied from 60dB to 100B through telecommand. To the best of the authors' knowledge, this is the first realization of an SSPA in Q-band for space applications, at least in Europe.