ANALYSIS OF NONLINEAR TRANSMISSION-LINES BY FREQUENCY-DOMAIN PERTURBATION METHOD

We discuss a numerical method for solving non-linear transmission line s in the frequency domain. Such transmission lines are widely used for communications such as in GaAs integrated circuits and varactor diode circuits. The circuit equations are described by non-linear partial d ifferential equations, so their analysis is very complicated compared with that of linear transmission lines. In this paper we propose a fre quency-domain perturbation method for weakly non-linear transmission l ines where the wave-forms are approximated by Fourier expansions and e ach frequency component is calculated by a modified perturbation metho d. To improve convergence, we introduce two new techniques, the compen sation method and the homotopy method, which help to make the iteratio n stable and can be applied to a wide class of non-linear transmission lines. We have analysed shock wave phenomena in example. (C) 1997 by John Wiley & Sons, Ltd.