Development of 150W S-band GaN solid state power amplifier for satellite use

150W S-band gallium nitride solid state power amplifier (GaN SSPA) has been developed for satellite use. GaN devices have been already used for various fields in lower frequency bands (L-band and S-band) such as ground station amplifier and radar system. For space application, there is great interest in realizing high power solid state power amplifier using GaN devices to achieve higher output power compare with current GaAs devices. Also there is very much interest for the performance comparison between GaN SSPA and traveling wave tube amplifiers (TWTAs). Development result shows that, with an electrical power conditioner (EPC), the GaN SSPA achieves output power of 148.6W with power added efficiency (PAE) of 53.8% which are almost equivalent to TWTA. Moreover, footprint and mass of this SSPA are much less than those of a TWTA. Also we confirmed through qualification testing that the GaN SSPA meets the environment requirements for satellite use.