Mixed mode S-parameters analysis for differential networks in integrated circuits

Abstract

In this paper, we extend the mixed mode S-parameter representation and its properties for a differential network commonly used in integrated circuits and printed circuit boards (PCBs). As an example of a differential network circuit, we illustrate the analysis of a pair of differential traces printed on a PCB using Ansoft HFSS to simulate the S-parameters. The differential pair is a typical transmission line that includes interconnects (vias) and is routed between PCB chip dies. Then we construct a differential schematic circuit using the simulated S-parameters of the PCB traces, and extract its associated Rx voltage signals and eye diagram.