Experimental demonstration of a silicon carbide IMPATT oscillator

Silicon carbide (SiC) is an excellent material for high-power and high-freq uency applications because of its high critical field, high electron satura tion velocity, and high thermal conductivity, In this letter, we report the first experimental demonstration of microwave oscillation in 4H-SiC impact -ionization-avalanche-transit-time (IMPATT) diodes. The prototype devices a re single-drift diodes with a high-low doping profile. DC characteristics e xhibit hard, sustainable avalanche breakdown, as required for IMPATT operat ion. Microwave testing is performed in a reduced-height waveguide cavity, O scillations are observed at 7.75 GHz at a power level of 1 mW.