Comparative Study of Lossy Transmission Line Simulation Models for Eye-Diagram Estimation

The aim of this study is to investigate and compare two simulation models of lossy transmission lines (TLs) for signal integrity analysis by an eye-diagram evaluation. The first one is a SPICE model obtained by applying the vector fitting technique, and consists of a cascade of ZY-TL unit cells, where Z and Y take into account the frequency-dependent losses, and TL is an ideal transmission line. The second simulation model is based on the behavioral modeling technique and the time-domain convolution. The lossy interconnect is described by S -parameters as response of a step function. The numerical solution of the convolution integrals can be directly implemented in a mathematical tool or either used to derive a digital wave network that can be processed by digital signal processing techniques. A comparative study of the two simulation models with full-wave and experimental results is provided considering a realistic test case such as traces in a printed circuit board. The advantages and disadvantages of the two models are finally highlighted.