Triple-wide-band Linear to Circular Polarization Converters Using Bi-layered Metasurfaces

Abstract

Multiband operation in linear to circular polarization conversion devices results in cost and volume reduction. In this paper, a tri-band Linear Polarization to Circular Polarization (LP-to-CP) converter is proposed using transmissivemetasurfaces; which has never been reported before. It converts incident linearly polarized waves into transmitted Circular Polarized (CP) waves in three frequency bands. The unit cell consists of two identical layers of metallic patterned layers consisting of penta squares arranged diagonally inside a square ring. Metallic layers are separated by a dielectric spacer. The detailed design procedure is proposed for tri-band LP-to-CP operation. As an example; the design of the tri-band LP-to-CP converter in microwave region in X, Ku and Ka-band is presented. The proposed structure converts incident X or Y polarized wave into transmitted circularly polarized wave in three wide frequency bands from 7.3167 GHz–9.5833 GHz, 25.45 GHz–31.4 GHz and 35.367 GHz–42.1667 GHz. After full-wave optimization in HFSS, the designed converter is fabricated and experimentally analyzed. Close agreement between simulated and measured results depicts the validity and reliability of the proposed design. The idea is endorsed by equivalent circuit analysis of the unit cell.