A wide-angle planar metamaterial absorber based on split ring resonator coupling

A wide-angle planar metamaterial structure exhibiting strong absorption is presented. The structure functions as a near-perfect absorber with the incident electric field propagating not only across but also along the gaps of individual split ring resonator (SRR) elements. It is the coupling of adjacent SRRs that provides capacitance necessary to excite the LC resonance for absorption. Both simulations and experiments are shown in this paper. The experimental results indicate that when the electric field propagates along the gaps of individual SRR elements, the structure obtains 1.6-GHz-wide absorption with absorptivity larger than 90% at small incident angles. The proposed structure offers a potential way to create azimuth-independent broadband metamaterial absorber.