Differential Signal EMI

Asymmetry in the design of differential signal interfaces results in the conversion of differential currents to common-mode currents. These common-mode currents are usually the primary source of EMI. Asymmetry exists to some extent in the driver, the trace or wire routing, and the termination. Missouri S&T researchers are evaluating and modeling the effects of various sources of asymmetry and determining their relative impact on radiated EMI in typical configurations. This will help designers of differential signal interfaces to minimize radiated emissions without imposing unnecessary constraints on their designs.