A Review on Electromagnetic Metamaterial Absorbers

Abstract

Metamaterials are artificially engineered materials that possess properties that are not present naturally. They show some specific properties such as negative refractive index, negative permittivity, negative permeability and left hand behavior. Metamaterial absorbers have greater attention in nowadays because of its ability to absorb incident electromagnetic radiation. The structure consists of resonator layer, dielectric substrate and metallic ground plane. They are applicable in radar cross section reduction (RCS), energy harvesting, electromagnetic shielding and refractive index sensing. In this paper, various metamaterial absorbers and their applications are reviewed. Initially the theory and working of metamaterial absorbers are discussed. Several multiband absorbers and their absorptivity are then presented. Next, the review focuses on several broadband absorbers and polarization insensitive absorbers. By using these metamaterial absorbers, we can make near-unity absorption.