A Multiband Circular Polarization Selective Metasurface

Abstract

Metasurface offers extraordinary possibilities to manipulate the polarization, phase and amplitude of the electromagnetic (EM) waves. The polarization manipulation property of metasurfaces became a great attraction for many researchers due to its vital importance in numerous applications such as beam splitting, antennas, sensor systems, radar cross section (RCS) reduction, contrast imaging, microwave and optical communication. Chiral metasurfaces, a subclass of metasurfaces, composed of a structure whose mirror image cannot be superimposed on top of itself. The existence of chirality in metasurfaces leads to outstanding EM properties like polarization selectivity and asymmetric transmission. In this thesis, a multi-band 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 consists of circular split-ring resonator with a cross shape structure inside it. The same structure is printed on the bottom layer 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 5.18-5.23 GHz for y-polarization. Similarly, for x-polarization, three 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. Furthermore, the response of the metasurface does not vary against oblique incidences up to 45○ . The simple design, angular stability, multiple operating bands and miniaturized profile make the proposed metasurface a potential candidate for polarization conversion applications.