High-power GaN MESFET on sapphire substrate

The first power results of GaN MESFET achieved at 2 GHz are presented. A power density of 2.2 W/mm has been obtained with an associated power added efficiency of 27% at V/sub ds/=30 V and V/sub gs/=-2 V. These results represent a significant improvement over similar MESFET's or HFET's grown on GaAs or InP substrates.