Statistical characterization of line-imbalance in differential lines

In this work, multi-conductor transmission line modeling and modal analysis are combined to develop a probabilistic model for the characterization of the unwanted common-mode (CM) voltages across the terminations of a differential line by possible imbalance of the wiring structure. Estimates for the probability density function of the transfer ratio between the differential-mode signal source and the theoretically null CM voltages induced at line terminations are cast in closed form as a function of the line geometrical parameters. The obtained predictions, validated versus Monte-Carlo simulations, are then used for a quantitative comparison with unwanted CM voltages due to imbalance of the line terminal networks.