FDTD ANALYSIS OF LOSSY, MULTICONDUCTOR TRANSMISSION-LINES TERMINATED IN ARBITRARY LOADS

A hybrid method is presented for incorporating general terminations in to the solution of lossy multiconductor transmission lines (MTL's). Th e terminations are characterized by a state-variable formulation which allows a general characterization of dynamic as well as nonlinear ele ments in the termination networks, The method combines the second-orde r accuracy of the finite difference-time domain (FDTD) algorithm for t he MTL with the absolutely stable, backward Euler discretization of th e state-variable representations of the termination networks, A compac t matrix formulation of the recursion relations at the interface betwe en the MTL and the termination networks allows a straightforward codin g of the algorithm, Skin effect losses of the line conductors as well as the effect of an incident field are easily incorporated into the al gorithm, Several numerical examples are given which contain dynamic an d nonlinear elements in the terminations, These examples demonstrate t he validity of the method and show that the temporal and spatial step sizes can be maximized, thereby minimizing the computational burden.