A 17.3-20.2-GHz GaN-Si MMIC Balanced HPA for Very High Throughput Satellites

Abstract

This letter presents the design and experimental characterization of a $K$-band high power amplifier (HPA) monolithic microwave-integrated circuit (MMIC) for the next generation of very high throughput satellites (vHTS). The MMIC is a three-stage balanced amplifier realized on a commercial 100-nm gate length gallium nitride on silicon (GaN-Si) technology. The design is compliant with space reliability constraints and, despite the larger thermal resistance and losses shown by the silicon (Si) substrate with respect to the more common silicon carbide (SiC), the realized HPA delivers, in pulsed condition, a peak output power larger than 41 dBm in the operative band from 17.3 to 20.2 GHz, with an associated power added efficiency (PAE) and gain up to 40% and 26 dB, respectively. In continuous wave (CW) operative conditions and with a backside temperature of 85 °C, the MMIC delivers a minimum output power and PAE of 39.4 dBm and 28%, respectively. Moreover, a 24-h test at saturated power has shown almost negligible performance degradations, thus providing confidence in the selected GaN-Si technology's robustness.