The typical current and voltage waveform of TRAPATT diode as well as its inherent physical parameters and operating parameters are investigated in this paper. The normalized impedance

power output

efficiency and characteristics of the harmonics in the large nonlinear range are analysed by using the frequency domain method. The requirements of impedance match between the device and the circuit in various operating conditions are obtained. The maximum possible efficiency of TRAPATT diode is estimated. The numerical calculations are given with some typical parameters of the device and the circuit in S-band as an example

and characteristic curves for different working conditions are plotted. The results

show that measured values of circuit impedance are close to those calculated from typical waveforms.