Modal Analysis for Induced Currents in Metallic Plates

A number of electromagnetic systems and devices comprise metallic plates, acting either as a structural support to other, active parts of the system, or as an electromagnetic shield. In the case of external anomalous or unwanted electromagnetic solicitations, the plates are interested by induced currents. The currents couples with electrically active parts of the system, generating spurious effects. The computation of reaction fields and the coupling with the structures to correctly size the protection circuits is usually done numerically. In this study, we propose a modal analysis of the plate current map to achieve a semi-analytical expression, and we attempt to relate plate modes to a suitable set of lumped elements to be integrated within an equivalent circuit of the system active parts for the sizing of the protection system.