A 4W 37.5-42.5 GHz Power Amplifier MMIC in GaN on Si Technology

the design of a Q-band high power amplifier (HPA) in Microwave Monolithic Integrated Circuit (MMIC) technology is presented. The HPA is fabricated in a 100nm gate length Gallium Nitride on Silicon (GaN-Si) technology. The HPA, based on a four-stage architecture, was designed accounting for the de-rating rules foreseen for spatial use and to work in continuous wave (CW) conditions. Nevertheless, the realized HPA can provide a saturated output power larger than 36.5dBm with a gain and a power added efficiency higher than 22dB and 30%, respectively, in the operative band from 37.5GHz to 42.5GHz. The chip area is 3.54 × 3.5 mm2. Such results are in line with others state-of-art HPAs realized in more expensive GaN processes based on Silicon Carbide, thus demonstrating that high resistivity Silicon substrate can be efficiently adopted also in such a peculiar application.