High efficiency operation of IMPATT diodes

A new mode of microwave power generation in avalanche diodes, with efficiencies greatly exceeding those obtainable from the IMPATT mode, has recently been discovered. The first experimental observation of these high efficieneies was reported by H. J. Prager, K. K. N. Chang and S. Weisbrod (RCA Laboratories), who observed 60% efficiencies at frequencies below 1 GHz with a silicon diode in pulsed operation. Later R. L. Johnston, D. L. Scharfetter and D. J. Bartelink (BTL) observed 40% efficiency at 3 GHz with a germanium diode also in pulsed operation. Their work in addition gives a theoretical explanation of the observations through detailed computer simulation. Most recently D. E. Iglesias and W. J. Evans (BTL) succeeded in obtaining 40% efficiency in continuous operation with a germanium device at frequencies below 1 GHz.