We have made a 4H-SiC RF power MOSFETs with cutoff frequency up to 12 GHz,
delivering RF power of 1.9 W/mm at 3 GHz. The transistors withstand 200 V drain voltage, are
normally-off, and show no gate lag, which is often encountered in SiC MESFETs. The measured
devices have a single drain finger and a double gate finger and a total gate width of 0.8 mm. To our
knowledge this is the first time that power densities above 1 W/mm at 3 GHz are reported for SiC
MOSFETs.