Design of wide-angle And Polarization-Insensitive Metamaterial Absorber

In this paper,we show the design of polarization-insensitive and wide-angle metamaterial absorbers(MAs). The proposed MAs consist of a traditional metal-dielectric-metal sandwich structure with FR-4 dielectric layer in the middle,and the top layer is diamond-shaped closed-ring resonators and the bottom layer is a metal black plate. The central ring in the unit cell is fixed, and the outside ring or inside ring is added without changing the parameters of the structure. By optimizing the geometric size and comparing these two types of double-ring resonators, we found that these two MAs both have properties of high absorption, polarization-insensitive and wide-angle absorption. Moreover, we found that it has better characteristics of the inside ring added to MA.