High-Speed Differential Via Optimization using a High-Accuracy and High-Bandwidth Via Model

A physics-based equivalent model of the high-speed differential via pair with high accuracy and high bandwidth is proposed for the first time. The proposed physics-based equivalent circuit model of the differential via pair includes the effect of adjacent ground (GND) vias. The proposed model is verified using 3D full-wave numerical simulation results. In addition, the change in electrical performance due to change in anti-pad radius, the via pitch and the GND-via–to-differential-via distance is analyzed. Based on the analysis, electrical performance of differential via pair can be accurately and rapidly optimized with respect to design parameters, such as the via pitch, the anti-pad radius and the GND-via-to-differential-via distance using the proposed model, to provide pre-layout design guide for high-speed channel designers. By using the proposed high-accuracy and high-bandwidth physics-based via model, the via optimization time can be drastically reduced with high accuracy.