Coplanar AlGaN/GaN HEMT power amplifier MMIC at X-band

A power amplifier MMIC based on AlGaN/GaN HEMTs was fabricated and measured. The coplanar balanced amplifier consists of two 8/spl times/100/spl mu/m transistors. Wilkinson splitters were used to divide and combine the power. BY biasing the amplifier at V/sub DS/=30V a maximum CW output power of 39dBm corresponding to 5W/mm with a maximum power added efficiency (PAE) of 33.8% was achieved at 10GHz. Biasing the amplifier at V/sub DS/=20V resulted in 36.7% PAE with 37.2dBm CW output power at 10GHz. To the author's knowledge these results represent the highest output power density so far achieved for GaN-based MMICs at X-band in CW mode.