Realization of bifunction: dual-band absorption and broad band polarization conversion by zigzag birefringent reflective metamaterial

In this paper, we propose and fabricate a kind of zigzag birefringent reflective metamaterial, the surface of which is a 1D rough surface. It can realize both multiple absorption and broadband polarization conversion at different frequency ranges of microwave. This metamaterial is made of a ring-shaped metal piece that is deposited on one side of a piece of grounded zigzag dielectric substrate. The absorptivities are 99.4% and 97.3% at 3.32 and 6.87 GHz respectively, and the polarization conversion ratio is more than 90% from 8.43 to 11.55 GHz, when the incident wave illuminates the sample with different polarization angles. A bifunctional device based on this metamaterial can act as either an absorber or a polarizer. This work is of significance to study the electromagnetic properties of rough surface metamaterials and provides an encouraging example in metamaterial design for combining different functions into one device.