Analysis of strongly nonlinear circuits with a frequency-domain method coupled with a consistent large-signal model

An analysis method that extends the applicability of frequency-domain methods to strongly nonlinear circuits is described. Nonlinearities are described with Chebyshev expansions which are evaluated with a numerically stable three-term recurrence formula. The method is coupled with a novel, measurement-based consistent modeling approach which allows improved accuracy in describing the frequency dependence of the measured small-signal parameters. The analysis method and modeling approach are experimentally verified by comparing measured and simulated results on a monolithic MESFET operating as mixer. The efficiency of the frequency-domain method is demonstrated by analyzing the intermodulation distortion of the mixer with three independent tones and over 100 frequencies, driven past saturation with strong RF signals, on a personal computer.<>