Steer and split electro-magnetic waves by employing ultra- thin anisotropic meta-material

As an ultra-thin developed form of meta-materials, metasurface does attract tremendous attention due to its flexibility in controlling wave front in different spectrums. In this paper, we propose a microwave metasurface with function of transforming spherical waves into plane waves and splitting waves according to polarized status of incident waves. By using a compact ultra-thin anisotropic element, we design a polarization beam splitter under spherical wave's illumination. With different phase gradients for x/y-polarized waves, the anisotropic metasurface has function of gain enhancement of 12.4 dB on average and reflecting x/y- polarized waves in -x/+y direction with the same reflected angel of 33° at the operating frequency of 15GHz. For verification of simulation results, the metasurface sample with size of 102×102mm2 and cells of 17×17 is fabricated and measured. Experimental results are in excellent agreement with the simulated ones, in which the high isolation of 30dB at 15GHz between x- and y-polarized waves is obtained. Due to the great performance in beam steering and thickness reduction, our design provides a promising approach of beam splitting, steering and gain enhancement in microwave region.