Abstract: The development of an AlGaN/GaN HEMT power MMIC on SI-SiC designed in microstrip technology is presented.A recessed-gate and a field-plate are used in the device processing to improve the performance of the AlGaN/GaN HEMTs.S-parameter measurements show that the frequency performance of the AlGaN/GaN HEMTs depends significantly on the operating voltage.Higher operating voltage is a key to higher power gain for the AlGaN/GaN HEMTs.The developed 2-stage power MMIC delivers an output power of more than 10W with over 12dB power gain across the band of 9~11GHz at a drain bias of 30V.Peak output power inside the band reaches 14.7W with a power gain of 137dB and a PAE of 23%.The MMIC chip size is only 2.0mm×1.1mm.This work shows superiority over previously reported X-band AlGaN/GaN HEMT power MMICs in output power per millimeter gate width and output power per unit chip size.

Key words: X-band, AlGaN/GaN, HEMTs, power MMIC