Modeling the impact of return-path discontinuity on interconnects for Gb/s applications

Return-path discontinuity (RPD) has a huge impact on the performance of interconnects carrying high-speed signals for Gb/s applications. In this contribution, we quantify the effects of RPD on both planar and vertical interconnects. For planar interconnects, we focus on the impact of slits on reference planes of embedded microstrip lines in thin-film re-distribution layers, considering the lossy nature of silicon. For vertical interconnects, we propose a circuit model that accurately captures the impact of RPD which occurs when signal vias transit power-ground plane pairs. This model can be used in the pre-layout stage to develop design guidelines to minimize the impact of RPD for Gb/s applications.