SiC microwave power technologies

Two SiC transistors that are investigated for microwave power applications are the 4H-SiC static induction transistor (SIT) and the 4H-SiC metal-semiconductor field-effect transistor (MESFET). Ultrahigh frequency 4H-SiC SITs have demonstrated record-breaking pulsed power per package (900 W) with excellent associated power-added efficiency (PAE) of 78%. S band 4H-SiC MESFETs have shown a record power-density of 5.6 W/mm and 36% PAE, as well as 80 W continuous-wave (CW) power (1.6 W/mm), with an associated PAE of 38%. X-band MESFET power density of 4.3 W/mm was obtained for exploratory CW devices. These performance gains are afforded by the advantageous material properties of silicon carbide. SiC SIT technology offers many military system advantages including lower cost, lower weight, higher power and high temperature of operation and higher efficiency transmitters with minimal cooling requirements. SiC RF MESFET's and circuits are candidates for use in efficient linear transmitters for commercial and military communications.