Two compact SRR resonators enabling five-band perfect absorption

A simple and compact five-band metamaterial absorber, consisted of two split-rings and a metallic board spaced by a certain thickness dielectric layer, is numerically investigated and studied. The designed absorber provides five obvious bands, and each resonance peak has the absorption coefficient great than 98.7% on average. The operating mechanism of five-band near-unity absorption is due to the combined effect of the LC, dipole and surface resonance of structure. Moreover, the effects of the parameters are investigated to verify the origin of the five-band absorption. The proposed device can be potentially used in biological sensing, material detection, and thermal imaging.