Impact of twist non-uniformity on crosstalk in twisted-wire pairs

In this paper, a novel circuit model for low-frequency crosstalk predictions in twisted-wire pairs (TWPs) is developed, that accounts for effects related to twist-pitch non-uniformity in length. It is shown that random fluctuations of the twist length may play a dominant role on crosstalk levels, depending on TWP load configuration. Crosstalk analytical predictions are validated against ad hoc experimental measurements and are confirmed by the outputs of a fully-numerical transmission line model. The proposed model overcomes limitations of previous models, based on the assumption of uniform twist-pitch and/or neglecting the line per-unit-length parameters, and it is valid in a wider frequency range.