Materials Effect on Shielding Effectiveness

With the continual increased concentration of the electric and electronic systems, with the increase of their working speed that results a large and dense use of the spectrum frequency and, finally with their miniaturization that increases their sensitivity to the electromagnetic interferences; the importance of problems of E/E equipment´s cohabitation and electromagnetic pollution has raised. Electromagnetic shielding is one of the most widely used techniques to fight against this kind of problem. The ability of a shielding enclosure is characterized by its shielding effectiveness. In this paper we present an analysis of the shielding effectiveness for different materials in function with frequency. This analysis is executed separately for electric, magnetic and electromagnetic fields. It is shown that materials are not equivalent to reduce electromagnetic fields. In this way, we are particularly interested by the chirality, chiral devices and their importance to improve the shielding effectiveness.