Study on Crosstalk and Mode Conversion of Two Pairs of Differential-Paired Lines with Different Distances

It is desired that EMC guidelines and ways of designing multi-conductor differential-paired lines at high frequency be established on the basis of research work on fundamental knowledge. To provide basic considerations for crosstalk and mode conversion of two pairs of differential-paired lines with different distances, this paper studies the dependencies of crosstalk and mode conversion evaluated with a mixed-mode S-parameter on the distance between two differential-paired lines using theoretical calculation and FDTD modeling. Good agreement between theoretical calculations and results calculated by FDTD demonstrates the validity of the proposed theoretical calculations. The dependencies of crosstalk and mode conversion are quantified. The proposed method provides enough flexibility for different geometric parameters and can be used to gain physical insights and develop design guidelines. This study has successfully established a basic method for effectively predicting crosstalk and mode conversion on two pairs of differential-paired lines.