We were honored to have Abbas Alwishah from Molex present at the 2026 SIMULIA Americas Users Conference in Novi, Michigan, May 13-14, 2026.
Abstract:
Shielded interconnects are a key element of electromagnetic compatibility (EMC) control in automotive electronic systems. Practical implementations involving connectors, braid terminations, and shield overlaps inevitably introduce microscopic gaps due to assembly forces, tolerances, and mechanical deformation. Although these gaps are typically only a few micrometers wide, they often dominate electromagnetic leakage paths and represent a common root cause of late-stage EMC test failures. Accurately predicting their impact using full-wave simulation is challenging, as direct modeling of such small and spatially varying gaps leads to excessive meshing requirements and long simulation times, limiting the usefulness of simulation for early design decisions.
This paper presents an efficient simulation methodology implemented in CST Studio Suite for early prediction of gap-induced EMC failures in automotive shielded interconnects. Structural simulation results are used to extract the spatial distribution of gap widths occurring at shield overlaps, connector interfaces, and braid termination regions. In the electromagnetic model, the physical micron-scale gaps are replaced by enlarged gap regions with constant thickness that can be meshed efficiently. The electromagnetic behavior of the original gaps is preserved by assigning spatially dependent material properties such that the capacitance per unit area remains unchanged and the propagation velocity of TEM modes in the gap equals the speed of light.
The approach is validated by comparing insertion loss and field distributions for different gap widths and modeling strategies over a wide frequency range. Results show that the method reliably predicts shielding degradation and coupling mechanisms relevant to automotive EMC testing. The presented workflow enables identification of EMC-critical interconnect features early in development, reduces late design changes, and supports faster time-to-market with improved EMC robustness.
Presenter:
Abbas Alwishah
Regional Technical Lead (Asia), EMC AND SI - Molex
Sr Engineering Manager | Automotive & Power Systems Expert
With over 25 years of engineering experience specializing in the intersection of power systems and advanced automotive electronics. His career is defined by a deep technical mastery of high-voltage architectures and high-speed data integrity in the area of interconnects and system level. Experienced in testing and simulations through out my career, in CST running Signal Integrity and EMC while are Molex and TE Connectivity the last 16 years. Leading a team of 10 Engineers for signal integrity globally over the last 8 years.
