Effect of stitching capacitor distance for critical traces crossing split reference planes

This paper examines the EMC effect of reference plane splits in modern-day printed circuit board (PCBs). Initially, the EMC impact of the reference plane split is quantified by measuring the gap voltage which exists under a high-speed signal line which crosses a reference plane split. This is accomplished through a variety of full-wave analyses. The effect on the digital signal integrity of the transmission line is also shown. Subsequently, a novel new circuit based treatment is introduced which significantly reduces the ill effects of the discontinuity. It is also demonstrated that circuit based tools, as opposed to full-wave tools, can provide accurate analyses of these effects if the recommended discontinuity treatment is employed.