Properties of metamaterial based electromagnetic absorbers and shields

Abstract

Metamaterials are widely investigated as nominates for absorbers and shields in Electromagnetic Compatibility (EMC) techniques. Due to the dispersive nature of artificially constructed metamaterials, permittivity and/or permeability can be negative at a certain band of frequency. Since the propagation constant has imaginary values in lossless SNG media, electromagnetic waves decay in these media and reflect at the surface. When the permittivity and permeability values are both negative, propagating waves are supported and impedance matching between a double negative (DNG) medium and air can be achieved. For this reason, single negative (SNG) materials can be used in electromagnetic shielding applications and DNG materials for realization of electromagnetic (EM) absorbers. Theoretical analysis of metamaterial (MTM) based electromagnetic absorbers and shields are investigated using S- parameter calculations, and properties are presented as a function of layer compositions and different dispersion parameters of medium permittivity and permeability values. The characteristics of EM absorber/shields are also observed when metamaterial layers are stacked on a metal plate.