Nonlinear modelling applied to one-port microwave active circuits

A recently developed nonlinear model for characterising two-terminal microwave active circuits under dynamic and steady-state conditions has been reduced to a form suitable for numerical calculations. The simplified model retains the nonlinear dependence of the active-device currents on RF voltage and frequency and it also takes into consideration the nonlinearity in frequency of the passive circuit. The model is applied to two hypothetically postulated Impatt-diode oscillators and dynamic solutions are calculated. Furthermore the calculated transients are compared with those obtained for a practical oscillator.