Magnetic Field Shielding by Multilayer Thin Sheets

Author: Giorgi Korkotadze
Keywords: Shielding Effectiveness, Analytical Approximation, Multi-Layer Shields
Annotation:

In electromagnetic compatibility (EMC) problem, the issue of shielding electromagnetic fields plays an important role. The electromagnetic shield is a kind of barrier, the purpose of which is to weaken or completely suppress unwanted electromagnetic radiation. The shielding effectiveness is typically defined as the ratio of the magnitude of the incident electric field, to the magnitude of the transmitted electric field. Shielding of electric fields are much easier rather than magnetic fields. The issue of far-field shielding is a well-studied, which can not be said in case of near-fields. Formula for shielding effectiveness in case of single-layer infinite sheet are given by Moser. The article presents the issue of near-field magnetic field shielding for single and multi-layer metallic structures. For single-layer sheet analytical and experimental results of the shielding effectiveness are given according to Moser’s publication. In case of multi-layer sheets analytical approximation were generalized for double and triple-layered shields. In this paper for multi-layer shields only analytical results are given.