Impact of Routing on EMI Resilience in High-Speed Digital PCBs: A Time-Domain Analysis

This paper investigates the electromagnetic interference (EMI) resilience of various microstrip transmission line (MSL) routing schemes commonly used in high-speed digital applications. The study focuses on minimizing crosstalk and enhancing signal integrity by optimizing the geometry and coupling between conductors. Traditional routing methods like meander and spiral configurations are compared against a novel scheme characterized by increased spacing between conductor turns. This proposed scheme allows for component placement beneath the transmission lines, potentially reducing overall printed circuit board (PCB) size. Quasi-static simulations are conducted using the TALGAT environment to evaluate the time-domain response of the different routing schemes to a Gaussian pulse excitation with frequencies ranging from 0 to 6 GHz. N-norms are employed to quantify the pulse characteristics and assess their potential impact on circuit performance and reliability. The results demonstrate that the meander configuration exhibits the lowest level of crosstalk, while spiral configurations show higher crosstalk, especially at high trace densities. Increasing the spacing between conductor turns in the proposed scheme effectively reduces crosstalk and enables modal decomposition, leading to a more desirable signal response.