SiC MESFET hybrid amplifier with 30-W output power at 10 GHz

We report here the demonstration of over 30 watts of output power at X band from a single 12-mm SiC transistor under pulsed-mode conditions. For small (250-μm) devices, we also report record high power densities of 5.2 W/mm at 3.5 GHz and 4.5 W/mm at 10 GHz. The 12-mm MESFET´s were tested in hybrid amplifiers, matched with chip capacitors and microstrip lines on 15-mil alumina. When operated at 9.7 GHz at a drain bias of 50 V and gate bias of -5.5 V, these hybrid amplifiers showed pulsed output power as high as 30.5 watts at 2-dB compression, with 7.6 dB linear gain. Furthermore, output power of greater than 27 W was obtained with devices from each of three wafers processed together, indicating the good wafer-to-wafer performance of the SiC power MESFET process