AlGaN/GaN HEMTs with PAE of 53% at 35 GHz for HPA and Multi-Function MMIC Applications

We would like to report on AlGaN/GaN HEMTs on SiC substrate with stat-of the-art power performance at Ka-band. Power gains of 5.6, 6.3 and 6.7 dB and peak PAE of 53, 53 and 51% were measured at 35 GHz when 200-mum GaN HEMTs were biased at 10, 15 and 20 volts, respectively. At 10 GHz, 400-mum GaN HEMTs exhibited maximum PAE of 67%, power gain of 11.3 dB and power density of 5.6 W/mm when devices were biased at 30 volts. Furthermore, we have also achieved 36 to 38.7 ilBm TOI at a wide range of 10 to 26 dBm total output power for a 400-mum GaN HEMT. Very low noise figures of 1.4 dB at 26 GHz were measured on 100, 200 and 300-mum wide GaN HEMTs as well. In this work, we have demonstrated that GaN HEMTs on SiC substrate is a much superior device technology to GaAs-based pHEMT for microwave applications up through Ka-band.