High-power 10-GHz operation of AlGaN HFET's on insulating SiC

We report the first high-power RF characterization of AlGaN HFET's fabricated on electrically insulating SiC substrates. A record total power of 2.3 W at 10 GHz was measured from a 1280-μm wide HFET at V/sub ds/=33 V. An excellent RF power density of 2.8 W/mm was measured on a 320-μm wide HFET. These values are a result of the high thermal conductivity of SiC, relative to the typical substrate, sapphire.