Abstract: We report our research on 1mm multi-finger gate 4H-SiC metal-semiconductor field-effect transistors (MESFETs). We design our own device process to fabricate n-channel 4H-SiC MESFETs with 100μm single gate,1mm total gate periphery,0.8μm gate length. The RF characteristics are studied. At fo＝2GHz,Vds＝30V,the maximum output power is measured to be 1.14W,with a gain of 4.58dB,power added efficiency 19%, and drain efficiency 28.7%.

Key words: 4H-SiC,  MESFET,  microwave,  wide band semiconductor