Impact of Common-to-Differential Mode Conversion on Crosstalk in Balanced Twisted Pairs

摘要

In this paper, crosstalk in wire-interconnections involving twisted wire pairs (TWPs) with non-perfectly balanced terminations is investigated. In the first part, properties of balancing devices are described by resorting to modal impedances, modal gains, and common-mode rejection ratio (CMRR). In the second part, a prediction model based on a statistical description of twist-pitch non-uniformity is exploited for crosstalk simulations, and validated via experimental measurements. The combined effect of: a) common-to-differential mode conversion at the TWP terminations; b) random non-uniformity of the twist-length along the TWP, is discussed.