Signal Integrity Analysis of Transmission lines in Anisotropic Substrate for High-Speed Data Transmission

Abstract

Continuous increase in high-speed data rates is essential in today’s world in order to keep up with Moor’s law scaling and to meet application demands. This increase in information transfer rates is essentially limited by the by the inherent characteristics of anisotropic material like printed circuit boards (PCB). One of the limitations is the non-uniformity distribution of resin and fiber in the printed circuit substrate material also known as anisotropic effects. Anisotropic effects introduce differential skew in the signal lines which leads to bit error rate (BER) and limits data rate and length of the transmission lines. It becomes a serious issue for data rates above 3Gbps. In this thesis, we focus on the anisotropic dielectric properties of PCBs. A solution for reducing phase difference between the differential pair is explored, studied, and simulated on IBIS-AMI models and equalization techniques are applied at the receiver to improve channel performance. Effect of phase difference, length, spread weaves and phase mismatch (isotropic materials) is analyzed to suggest design rules for overall improvement in channel performance.