HIGH-TEMPERATURE DC AND RF PERFORMANCE OF P-TYPE DIAMOND MESFET - COMPARISON WITH N-TYPE GAAS-MESFET

The dc and RF performance of a p-type diamond MESFET is simulated and compared with the simulated performance of an n-type GaAs MESFET over the operating temperature range, 300-923 K. Power performance of a dia mond MESFET is shown to improve with increasing temperature and to exc eed that of a GaAs MESFET when operated at temperatures higher than 55 0 K. At 923 K the simulated diamond MESFET produces about 0.8 W/mm of output power for an operating frequency of 5 GHz. Small signal current gain for a diamond MESFET is also found to increase with temperature. The cut-off frequency, f(T), of a diamond MESFET at 923 K is comparab le with that of a GaAs MESFET at room temperature. It is concluded tha t microwave power applications of MESFET's in p-type diamond but other wise conventional design is limited to high temperature.