X-Band 100-W High-Voltage GaN Internally Matched FET with Low Gain Compression

We report on the design, fabrication, and characterization of an X-band 100-W Internally Matched FET (IMFET) designed for deployment in the Deep Space Antennas of the European Space Agency (ESA). The IMFET is based on high-voltage GaN dice, rated for a supply voltage of 100 V and serves as a feasibility study of a currently developed 200-W device, which is planned to be integrated into a 5-kW prototype amplifier system covering the antennas’ uplink band, ranging from 7.145 to 7.235 GHz. Measurements at a drain-source voltage of 70 V show an output power of more than 120 W at a power-added efficiency of 44.1% and a transducer gain higher than 15 dB, all reached at a compression level of 1 dB.