Simulation of Jumps in the Power Characteristic of a Quasi-Active Microwave Limiter Based on P-I-N Diodes

The reason for jumps observed in the experimental input-output power characteristic of a GaAs integrated limiter with a 1.8-mum-thick i-layer at a frequency of 9.4 GHz is found. The simulation is carried out in the time domain by numerically solving an initial-value problem for a nonlinear system of equations describing the electrical circuit of the limiter. A model of nonlinear elements, catching and detecting diodes, includes the drift-diffusion model and the equation for total current. It is shown that the dependence of the amplitude of the basic harmonic of the current through the diode on the amplitude of the basic harmonic of the voltage across the diode represents an S-shaped curve and that it is such a shape of this curve for the detecting diode that is responsible for the output power jumps. The simulation results for the limiter with a 1.2-mum-thick i-layer at frequencies of 3, 9.4, and 25 GHz are also presented. The amplitude modulation of the output signal at 25 GHz is observed.