Angular- and Polarization-Insensitive Metamaterial Absorber Using Subwavelength Unit Cell in Multilayer Technology

In this letter, we propose a novel metamaterial absorber with angular and polarization insensitivity using multilayer technology. The miniaturized unit cell of the proposed absorber consists of a split-ring-cross resonator (SRCR) on the middle layer with a metallic ring on the top layer and meander line on the bottom layer. Because additional capacitance and inductance are generated by metallic patterns on the top and bottom layers, the resonance frequency is shifted to a lower frequency and the electrical size of the unit cell dramatically decreases. The principle of miniaturizing the unit cell is described in detail by a parametric study, and the performance of the proposed absorber is demonstrated by full-wave simulation and measurement. The proposed absorber can achieve a high absorptivity at 10.28 GHz and maintain it for different polarizations and incidence angles.