A Review on Electromagnetic Metamaterial Absorbers and Its Application

Metamaterial absorbers have gained attention due to their ability to absorb incident electromagnetic radiation. They can be used for refractive index sensing, energy harvesting, electromagnetic shielding, and radar cross section reduction. These absorbers are made up of a dielectric substrate resonator layer, and metal-based ground plane. Various types of absorbers have been studied, comprising polarization-insensitive absorbers, broadband absorbers, and multiband absorbers. The goal is to achieve near-unity absorption. Metamaterial-based absorbers utilize left-handed material properties, permittivity, and permeability to reduce the size and thickness of the absorbers. Different design approaches and configurations have been studied to increase absorptivity. These absorbers have potential applications in communication technology to reduce the adverse effects of electromagnetic radiation. The current rapid progress in wireless communication is seriously exacerbating electromagnetic interference (EMI) and contributing to EM pollution, which is destroying the climate. In addition to air, noise, and water pollution, electromagnetic radiation has been identified as the fourth major source of pollution in the public sphere. It has detrimental consequences on all living things. Moving forward, there will be a growing need to develop suitable methods and materials to overcome electromagnetic interference. Three methods exist for controlling electromagnetic interference: absorption, transmission, and reflection. Nevertheless, absorption results in the reduction of electromagnetic waves; reflection and transmission of electromagnetic waves do not weaken the EMI field. Therefore, using a suitable electromagnetic wave absorber is a workable method for addressing the problem of electromagnetic interference (EMI). To absorb the visible light spectrum, which spans frequencies from 400 THz to 700 THz, carbon and black bodies are utilized. Materials that absorb sound waves, such as rock wool and glass fibers, are utilized to absorb frequencies between 20 Hz and 20 kHz. Similar to this, the RF and microwave regions of electromagnetic waves are absorbed by means of an electromagnetic wave absorber. Overall, research on metamaterial absorbers aims to develop materials and techniques for effective absorption of electromagnetic waves.