A Perfect Metamaterial Absorber

TL;DR

This paper introduces a novel metallic metamaterial absorber with near-unity absorbance, optimized for imaging, featuring a design that separates electric and magnetic resonances, and demonstrating high experimental absorption at 11.5 GHz.

Contribution

The paper presents a new design for a metallic metamaterial absorber with high absorbance and independent substrate selection, advancing imaging applications.

Findings

Achieved over 88% peak absorbance at 11.5 GHz.

Designed a structure with a 4% FWHM absorbance bandwidth.

Simulated absorbance of 96%, experimentally over 88%.

Abstract

We present the design for an absorbing metamaterial element with near unity absorbance. Our structure consists of two metamaterial resonators that couple separately to electric and magnetic fields so as to absorb all incident radiation within a single unit cell layer. We fabricate, characterize, and analyze a metamaterial absorber with a slightly lower predicted absorbance of 96%. This achieves a simulated full width at half maximum (FWHM) absorbance of 4% thus making this material ideal for imaging purposes. Unlike conventional absorbers, our metamaterial consists solely of metallic elements. The underlying substrate can therefore be chosen independently of the substrate's absorptive qualities and optimized for other parameters of interest. We detail the design and simulation process that led to our metamaterial, and our experiments demonstrate a peak absorbance greater than 88% at 11.5 GHz.