Incorporation of terminal constraints in the FDTD analysis of transmission lines

A method of incorporating lumped terminal conditions into a finite-difference, time-domain (FDTD) analysis of multiconductor transmission lines is given. The method provides an exact solution of the transmission-line equations via the FDTD technique when the line discretization, Δt, and the time discretization, Δt, are chosen such that Δt=Δz/v where v is the phase velocity of propagation on the line. Examples are given to show that in the case of a multiconductor line in an inhomogeneous medium where the mode velocities are not identical, the method gives accurate results with a minimum of computational effort