GaN-on-Si based 10W MMIC Power Amplifier for 5G K-Band Satellite Payload

In this contribution are presented the activities performed towards the realization of the first very high-power solid-state power amplifier, based on GaN technology, targeting more than 130W of output power in the frequency range 17.3-20.2 GHz, conceived for the next generation of K-band Very High Throughput Satellites (vHTS) for 5G applications. For this purpose, specific Monolithic Microwave Integrated Circuits (MMICs) Power Amplifiers (PAs) were developed on a commercially available 100 nm gate length Gallium Nitride on Silicon (GaN-Si) process (OMMIC process D01GH). The design was carried out considering space reliability constraints on electrical parameters and accounting for the spacecraft temperature limits, which are extremely challenging for this technology, to keep the junction temperature in all devices below 160 °C in the worst-case condition (i.e., maximum environmental temperature of 85 °C). The final MMIC, based on a three-stage architecture, demonstrates on wafer and in pulsed condition to achieve a minimum output power and power added efficiency (PAE) of 10W (40dBm) and 35% (with a peak of 45%) in the full Ka-band satellite downlink, i.e., from 17.3 GHz to 20.2 GHz. The packaged version demonstrates in continuous wave (CW) condition an output power larger than 39.5dBm with a PAE better than 30%. Moreover, long-time (24h) CW test at saturated power has shown almost negligible performance degradation, thus providing confidence in the selected GaN-Si technology’s robustness.