On the representation of coupled lossy transmission lines using transfer functions

Interconnections in computer systems must be treated as transmission lines rather than short circuits. Signal delays and crosstalk become more significant as transition times and geometric sizes decrease. The line is described by a model with frequency-dependent parameters, whereas the terminating networks are usually nonlinear and thus can be described in the time domain. One method for transient simulation of multiconductor lines expands the frequency-dependent variables into rational functions, which can then be simulated in the time domain. Algorithms for approximating this transfer function are presented. A nonlinear minimization method is described, it generates a polynomial ratio with poles located in the complex left half plane