SPICE models of Shielded Twisted-Wire Pairs for Radiated Immunity Analyses

In this paper, SPICE models suitable to analyze the radiated immunity of shielded twisted-wire pairs (TWPs) are proposed. The equivalent circuits representation of shielded TWPs are firstly derived from the multiconductor transmission line (MTL) theory. Then, by the method of vector fitting (VF), the equivalent circuits are approximated by rational functions, which can be directly converted to SPICE models. The models are suitable for transient analyses and allows the incorporation of any kind of terminations (including non-linear or time-varying loads). Numerical results of port voltages induced on a shielded TWP induced by incident plane wave are presented and compared with other approaches.