| Electromagnetic coupling is a critical factor in electromagnetic compatibility (EMC) and electromagnetic interference (EMI). The functionality of an electronic device or system is compromised when radiated fields penetrate to the internal elements in a shielded system.; In order to analyze these EMI/EMC issues, a characterization of electromagnetic coupling is needed. A useful characterization must account for the essential features which affect the amount of radiative energy that may penetrate a system. In this work the key features are considered to be (1) the packaging: how the device or system is contained, (2) the coupling mechanism: what path is available for radiative energy penetration, and (3) the internal components: the conducting elements which comprise the system or device.; A hybrid finite element method (FEM)/method of moments (MoM) model is presented that accounts for these key features in a realistic model of electro-magnetic coupling to a shielded enclosure populated with thin-wires. Coupling occurs through a narrow-slot aperture in the wall of the enclosure. The slot has both width and depth, as well as losses, which are accounted for via the equivalent antenna model of Warne and Chen. The shielded enclosure is modeled as an irregular cavity, with imperfectly conducting walls. The internal system components are modeled as multiple thin-wire segments in the coupled region.; The focus of this work is the addition of thin-wires to the coupled interior of the enclosure. Therefore, coupling results are presented depicting various slot/wire/cavity combinations and the resonant interactions are analyzed. Peak coupling, both with and without wires in the coupled region, is computed. With this data, a realistic characterization of shielding effectiveness is obtained. |
