Chiral Metasurface Based Design for Microwave Applications

Abstract

Metasurfaces have found in recent years several different applications like lensing, holograms in real time, increasing the gain of antennas, beam splitting, reducing the cross section of radar, polarization conversion. Polarization manipulation has always been important to scientific and engineering community due to its diverse applications. Many techniques have been employed to attain polarization control through conventional methods, but they require bulky size and have narrow bandwidths. To avoid these difficulties scholars tend to use metasurfaces. In this thesis a novel chiral metasurface has been designed for multiple operations at microwave frequencies, like asymmetric transmission and optical activity in transmission mode. The chiral metasurface has ability to obtain linear cross polarization conversion of incident electromagnetic wave in transmission mode within the bands of 4.47 GHz to 5.34 GHz and from 16.22 GHz to 16.88 GHz. The chiral metasurface is formed by an “h” shaped air groves drilled in the copper film on both sides of the dielectric layer, which exhibit dual band asymmetric transmission with cross polarization conversion with high efficiency accompanied with optical activity. The proposed chiral structure is useful in communication network like devices and non-reciprocal electromagnetic devices which make it strong applicant for applications in C and Ku bands of microwave regimes.