Power-Frequency Characteristics of the TRAPATT Diode Mode of High Efficiency Power Generation in Germanium and Silicon Avalanche Diodes

High efficiency oscillations in silicon avalanche diodes were first reported in April 1967 by Prager, Chang, and Weisbrod. 1 The new high efficiency mode was shown experimentally to be capable of converting dc to microwave power with efficiency greatly exceeding that predicted for the classical I M P A T T mode. 2 - 4 For example pulsed bias operation with 60 percent efficiency at about 750 MHz was reported. 5 Normal I M P A T T operation for this structure would be at about 4 GHz with perhaps 10 percent efficiency. 799 800 T H E BELL SYSTEM TECHNICAL JOURNAL, M A Y - J U N E 1970 The first theoretical calculation 6 of the high efficiency mode was obtained by computer simulation of carefully characterized experimental results 7 on germanium structures. Pulsed bias operation, with output power of 7.5 watts at 2.6 GHz with efficiency of 40 percent was reported. 8 The mode of oscillation was named T R A P ATT, for TRApped Plasma Avalanche Triggered Transit, which describes the new physical mechanisms discovered by the computer simulations. Characterization of experimental circuits 9 which support T R A P ATT oscillations and additional more detailed simulations 10 of the diodecircuit system further verify the avalanche-triggered-trapped plasma description of the high efficiency mode. In this paper a simplified model, previously described, 11,12 for the physical processes occurring in T R A P A T T operation is employed in order to analyze a wide range of structures and operating conditions.