A multiband circular polarization selective metasurface for microwave applications.

In this research article, a multiband circular polarization selective (CPS) metasurface is presented. A reciprocal bi-layered metasurface is designed by introducing the chirality in the structure. The top layer of the proposed metasurface is composed of circular split-ring resonator with a cross shape structure inside it. The same structure is printed on the bottom side of the proposed metasurface by rotating it at an angle of 90° to achieve chirality in the structure. The proposed metasurface is able to add CPS surface capability between 5.18 and 5.23 GHz for y-polarized incident wave. For the frequency band of 5.18-5.23 GHz, the transmission goes up to - 4 dB, while the polarization extinction ratio (PER) reaches up to - 27.4 dB at 5.2 GHz. Similarly, for x-polarized incident wave, three strategic CPS operating bands are achieved within the frequency ranges of 10.64-10.82 GHz, 12.25-12.47 GHz, and 14.42-14.67 GHz. The maximum PER of 47.16 dB has been achieved for the 14.42-14.67 GHz frequency band at 14.53 GHz. Furthermore, the response of the metasurface does not vary against oblique incidences up to 45°. The simple structure, angular stability, multiband and miniaturized size make this metasurface an outstanding applicant for polarization conversion and biomedical applications.