TRANSIENT ANALYSIS OF LOSSY MULTICONDUCTOR TRANSMISSION-LINES IN NONLINEAR CIRCUITS

Using the frequency-dependent transmission line parameters, two time-domain models are developed for lossy multiconductor transmissions lines. It is shown that the endpoints of a lossy multiconductor line can be represented at each time step by discretized Thevenin or Norton equivalent circuits. Because these models contain only lumped elements, they can be easily implemented in a general circuit analysis program for simulating the transient responses of nonlinear circuits. The analysis procedure developed makes exclusive use of infinite line impulse responses in the formulation of the time-domain models. Because infinite lines are matched, there are no reflections in the impulse responses. The result is that these impulse responses are relatively short. Of particular interest is the interconnection of high-speed digital circuits by lossy multiconductor transmission lines containing discontinuities. For the first time, results are shown for the most general case of lossy multiconductor transmission lines with discontinuities and nonlinear terminations in which the modal transformation matrices are necessarily frequency dependent.