A novel metamaterial absorber with perfect wave absorption obtained by layout design

In this work, a novel metamaterial absorber (MMA) with perfect wave absorption is designed through the layout optimization. The rotationally symmetrical design domain is determined by considering polarization insensitivity. The symmetrical design variables are related with each other. The optimization objective is to maximize the absorption index which is described by the reflection and transmission coefficients in the frequency range of 8–12 GHz with the constraint of volume fraction. The maximum absorptivity of the optimized MMA reaches 99.89%. And it has the polarization insensitivity, the wide range of oblique incident angles and the ideal impedance matching with the free space. Furthermore, the absorption frequencies exhibit regular variations while changing the sizes of unit cell and the thickness of dielectric substrate. Inspired by these analysis results and the existing researches, the multilayer MMA is designed in order to broaden the absorption band efficiently. The absorption frequency band reaches 1.1 GHz while the absorptivity is more than 85%.