A UNIVERSAL MODEL FOR LOSSY AND DISPERSIVE TRANSMISSION-LINES FOR TIME DOMAIN CAD OF CIRCUITS

In this paper, the Branin's method of characteristics has been extended to obtain a universal equivalent model for lossy and dispersive transmission lines. Existing CAD software packages, such as SPICE, can be used for this implementation. The starting point for obtaining the model are the a alog filters that approximate the characteristic impedance Z0(s) and the propagation function F(s) = exp (-lambda-l) of the transmission line. The circuits are synthesized using conventional network synthesis techniques. An examination of the validity of the model is carried out analyzing an example of RLCG lines driven by bipolar logic gates and the distortion of a Gaussian dc pulse as it propagates along a microstrip line.