Extended harmonic balance method

A new approach for frequency domain analysis and periodic steady state analysis of nonlinear circuits is described. Beside the variables generally used in the harmonic balance method (HBM) this method also uses a reduced waveform as a function of time. As a result, the number of harmonics in the HBM is limited to the harmonics requested for output results. The waveform in time is used to ensure the requested accuracy. The approach leads to a large speed improvement compared with ordinary HBM, without reducing accuracy and convergence properties of the Newton iteration process. The speed improvement is demonstrated by an example taken from an actual design