Anticipating EMI and on-board interference in automotive platforms

A dual-step MTL/FDTD strategy is proposed for anticipating full-vehicle level EMI. In the first step, the current distribution along a cable bundle connecting to electronic modules on an automotive platform is calculated using multiconductor transmission-line (MTL) models. In order to account for common-mode discontinuities on the vehicle chassis, e.g., slots, 3D full-wave modeling (FDTD) is used to determine radiation impedances, which are thereafter incorporated in the MTL models for compensating the radiation power loss. In the second step, the obtained currents are implemented as impressed current sources in full-vehicle full-wave modeling using an FDTD multi-wire subcellular algorithm. Thus, the full-vehicle emissions from the automotive harness and the common-mode discontinuities of the vehicle chassis can be predicted. The effectiveness and limitation of this approach have been demonstrated in a controlled laboratory environment.