Design, Realization and Characterization of a Wide-Angle Microwave Metasurface Absorber

In this article, we present a metamaterial absorber (MMA), and more specifically a metasurface based on a periodic structure consisting of double split-ring resonators (dSRR) which efficiently absorbs electromagnetic radiation for a wide range of incidence angles for both the transverse electric (TE) and the transverse magnetic (TM) polarizations. The proposed unit cell was designed employing a full 3-D electromagnetic solver based on the Finite Element Method (FEM). The unit cell consists of a square split-ring resonator and a thin metallic plate separated by a dielectric layer. Investigations of parameterization and optimization have shown that small modifications in the geometry of the resonator led to enhanced angular absorption. The numerical simulation stage was followed by design and fabrication of a prototype containing several unit cells. The measurements on the prototype show an absorbance peak larger than 84% and 58% for the incidence angles θ=0˚ and θ=70˚ respectively, at 9.73 GHz. The proposed MMA and its variations enable numerous applications such as defense systems, communication and stealth technologies.