Causality enforcement in transient simulation of passive networks through delay extraction

Causality, which deals with the precise timing of signal propagation through passive structures like interconnects, is an important problem in the time domain simulation of distributed passive networks. If unaccounted for, it can lead to significant error in the signal integrity analysis of high-speed digital systems. This paper demonstrates the enforcement of causality on the transient simulation of distributed passive networks based on the extraction of the port-to-port delay. The paper describes a technique to extract the port-to-port delay in passive networks directly from their frequency domain response. The technique can be applied to either S, Y or Z parameters of passive networks and can be extended to multi-port and mixed mode networks.