First Achieved 30 % P-N Junction GaAs Hi-Lo Impatt Diodes Having MTTF of 1011 Hours

By improving the carrier profile of a P-N junction GaAs IMPATT diode with a Hi-Lo structure, an efficiency of 30%, which is comparable to that of an excellent pt Schottky barrier type, has been first achieved. The diode showing the excellent 30% efficiency is depleted with the electric field of 20 kV/cm at the end of the drift region. The narrowed avalanche region and the reduced carrier concentration of the drift region enable the diode to operate at notably reduced bias voltage and current. Owing to the high reliability expected for the P-N junction type, the high efficiency and the low input power, output power of 3 watts is obtained with MTTF of 1011 hours.