Analysis of Optimum Rotation Angle for Mitigating P/N Skew Based on Geometrical Method

In this paper, a geometrical method is proposed to analyze the effect of rotation angle to the P/N skew. The simplified grid model is used to represent the 3D weaved glass fiber structure and the volume ration of glass and resin is used to compute the equivalent dielectric constant. Based on that equivalent dielectric constant, a geometrical method is proposed to compute the distribution of P/N skew with the rotated angles and the relative locations of traces to the glass weave. The results have reasonable agreement with the simulated results by 3D electromagnetic simulators. The optimal rotated angle for mitigating the P/N skew is analyzed which shows that the best rotation angel depends on the trace and the glass wave parameters.