AlGaN/GaN MODFETs on semi-insulating SiC with 3 W/mm at 20 GHz

The power performance of AlGaN/GaN MODFETs grown on semi-insulating SiC is reported. The epitaxial layers were grown by MOCVD with a good uniformity and excellent carrier mobility of 1300 cm²/Vs at room temperature. Devices with gate length of 0.3 μm were fabricated and characterized, yielding a record transconductance of 300 mS/mm. Active load-pull measurements yielded 594 mW total output power at 20 GHz. At 15 GHz a total output power of 3.3 W was measured. To the authors' knowledge, these results represent the highest output power so far achieved from a single GaN-device at Ku and K-band.