Statistical estimation of the electromagnetic noise induced by field-to-wire coupling in random bundles of twisted-wire pairs

The common-mode voltage induced by an external plane-wave field in the terminal loads of a bundle of twisted-wire pairs (TWPs) is investigated. In particular, a deterministic bundle is firstly considered (i.e., a bundle with TWPs running parallel each other), and the different factors determining the variability of the induced voltage with the position of the TWP in the bundle cross section are explained by the light of an analytical closed-form model. These fluctuations, whose statistics is here analyzed through numerical simulations, are the main responsible for the sensitivity to external noise of random bundles (i.e., hand-made bundles with random positioning of the TWPs along the bundle length). It is shown that the induced voltage tends to be normally and Rayleigh-distributed for electrically-short and electrically-long random bundles, respectively.