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A new technique based on the two-dimensional Fourier transform is presented and applied to the study of nonlinear wave propagation phenomena in one-dimensional, finite, nonlinear transmission lines. The technique permits determining the effects of nonlinearities and boundary conditions on the Fourier transform and identifying incident and reflected waves and solitons which may propagate through the transmission line at constant speed. The effects of windows on the Fourier transform are also assessed in both linear and nonlinear transmission line models. >

In designing microwave circuits the use of computer aided design (CAD) techniques is invaluable. Continuation methods using different types of predictors are implemented and their performance is evaluated in two nonlinear circuits (a lumped element one and a microstrip one) analysed by the harmonic balance technique. The comparison is carried out taking into account the error in the predictors and the number of iteration the solver needs to reach the next solution point. In doing so, the possibility of making the predictor adaptive is discussed.

A harmonic balance technique is used to study the formation and interaction of solitons in discrete, lossless, nonlinear transmission lines as a function of the number of harmonics, number of LC-cells, and pulse height and width at the generator. It is shown that the number of harmonics required to accurately determine the soliton formation and propagation increases as the generator's fundamental frequency is decreased, and that about 500 LC-cells are needed to observe the propagation and interaction of solitons. It is also shown that, for the calculations presented, the transmission line is almost perfectly adapted. A Taylor series expansion was used to determine the continuous analog of the discrete transmission line presented. >