TRANSIENT SIMULATION OF NONUNIFORM COUPLED LOSSY TRANSMISSION-LINES CHARACTERIZED WITH FREQUENCY-DEPENDENT PARAMETERS .1. WAVE-FORM RELAXATION ANALYSIS

In this Part I of two-part paper we present the waveform relaxation technique for simulating the transient response of nonuniform coupled transmission lines which are characterized with frequency dependent parameters. The method consists of iterative waveform relaxation analysis of asymmetric disjoint resistive networks constructed with voltage-dependent voltage sources generated by applying the fast Fourier transform (FFT). The method requires neither convolution integration nor synthesis of lumped equivalent circuits for the simulation of the frequency-dependency of transmission-line parameters. Transient responses of uniform and nonuniform coupled transmission lines with and without skin-effect parameters and terminated with linear and nonlinear loads are simulated for illustrations. The accuracy and efficiency of the relaxation technique are substantiated with exact analytical solutions and experimental data. In Part II of this paper we shall present the discrete-time transient simulation of coupled lossy transmission lines.