High-power microwave GaN/AlGaN HEMT's on semi-insulating silicon carbide substrates

Record performance of high-power GaN/Al0.14Ga0.86N high-electron mobility transistors (HEMT's) fabricated on semi-insulating (SI) 4H-SiC substrates is reported. Devices of 0.125-0.25 mm gate periphery show high CW power densities between 5.3 and 6.9 W/mm, with a typical power-added efficiency (PAE) of 35.4% and an associated gain of 9.2 dB at 10 GHz, High-electron mobility transistors with 1.5-mm gate widths (12 x 125 mu m), measured on-wafer, exhibit a total output power of 3.9 W CW (2.6 W/mm) at 10 GHz with a PAE of 29% and an associated gain of 10 dB at the -2 dB compression point. A 3-mm HEMT, packaged with a hybrid matching circuit, demonstrated 9.1 W CW at 7.4 GHz with a PAE of 29.6% and a gain of 7.1 dB, These data represent the highest power density, total power, and associated gain demonstrated for a III-Nitride HEMT under RF drive.