Characterization of avalanche diode TRAPATT oscillators

The characteristics of a coaxial avalanche diode oscillator circuit are calculated and compared with experimental results. The circuit admittance, as seen at the diode terminals, is calculated in the frequency domain for "optimally tuned" experimental conditions. The impulse response function of the circuit, as obtained from the transformed admittance, is used to obtain time-evolution solutions of the avalanche diode circuit system. The impulse response is more general than the previously employed differential equation characterization of a lumped element equivalent circuit. The simulation presented of the high-efficiency mode of oscillation allowed no adjustable parameters and is in excellent agreement with experiment. The simulation verifies the original TRAPATT [1] explanation for the high-efficiency mode of oscillation.