Modelling EM-Coupling on Electrical Cable-Bundles with a Frequency-Domain Field-to-Transmission Line Model Based on Total Electric Fields

This article deals with modelling of EM-coupling on cable-bundles installed in 3D structures. It introduces a modified-Field-to-Transmission-Line model for which the specificity is to account for the reciprocal interaction between EM-fields and induced currents by considering equivalent total field sources. The first part of the paper is devoted to the derivation of this model starting from Agrawal's classical Fieldto-Transmission-Line applied on a two-wire Transmission-Line and leads to a Transmission-Line model in which the signal-wire is now referenced to a fictitious surrounding cylinder acting as a return conductor. The modified-Field-to-Transmission-Line model is then obtained by modifying this derived-model in such a way that it is made compatible with numerical approaches and tools based on Agrawal's Field-to-Transmission-Line model. This modification involves a kL coefficient equal to the ratio of the two per-unit-length inductances of the classical and derived Field-to-Transmission-Line models. Validations of this modified formulation clearly show the capability of this model to predict precise wire responses including EMradiation losses. The second part of the paper is devoted to its extension to Multiconductor-Transmission-Line-Networks. The process relies on the capability to define an equivalent wire model of the cable-bundle in order to derive the kL coefficient and to numerically evaluate equivalent total field sources. Validation of this extrapolation is presented on a real aircraft test-case involving realistic cable-bundles in order to assess the potentiality of the method for future problems of industrial complexity.