Analysis of signal propagation in high-speed differential signal lines with full-wave time-domain technique

With the advancements in electronics, interests in interconnect of high-speed digital circuits and IC packaging have greatly increased in EMC community for signal integrity (SI). However, in order to take complex electromagnetic effects such as radiation, reflection and coupling into account, full-wave numerical techniques must be resorted, which usually result in intensive computation. This paper presents the investigation in electrical performance of differential signaling transmission lines, an increasingly used high-speed interconnect, by using the finite-difference time-domain (FDTD) method. The MPI-based parallel FDTD implementation is firstly discussed and a simple FDTD thin sheet algorithm is considered for imperfectly conductive strip lines. The characteristic impedance of, current distributions in, the reflection from the termination in, the effects of through via in, and the radiation from differential signal lines for even and odd modes are then investigated. The deep insights acquired is useful to optimize interconnect designs with differential signaling transmission lines for SI and EMC purposes.