Effective and Efficient Modeling of Differential Vias Using Semi-Empirical Approach

In this work, we present an effective method to analyze and predict the performance of a pair of differential via through multilayered printed circuit boards (PCBs). A pair of differential vias can be modeled as twin-rod transmission lines in a circuit model. By applying the equations for characteristic impedance in a circuit simulator, this model can quickly and effectively predict the behavior of the differential-via structure in a wide bandwidth. The modeled S-parameters were compared with those from a full-wave finite element method (FEM), it has shown that our model can describe real and practical differential-via structures for high speed applications.