2D Metamaterials for Blinds and Polarization Conversion Applications

Metamaterials are artificial materials possessing peculiar permittivity and permeability properites which are beyond the naturally occurring conventional materials. This paper presents the use of 2D metamaterial structures called frequency selective surfaces (FSS) to (i) Provide wireless security by reducing interference from unlicensed ISM frequency bands entering into a room by installing FSS on window blinds (ii) Achieve polarization conversion for polarization sensitive wireless communication systems. FSS structure consists of periodic arrangement of conducting elements or unit cells on a substrate. The proposed FSS structure on window blinds is very simple and is made of plus type unit cells. It acts as band stop filter to block multiple unwanted frequencies for different angles of rotation of the blinds. The transmission coefficients are studied for different angles of rotation of the blinds using simulations. Another FSS structure with concentric square split ring resonators (SRR) as unit cell achieves polarization conversion (PC) by polarizing the unit cells magnetically or electrically. The proposed SRR based FSS structure achieves polarization conversion over a wide bandwidth with good polarization conversion efficiency unaffected by angle of incidence of the incoming wave. Both FSS structures are realized on FR4 Epoxy substrates in EM simulation software High Frequency Structure Simulator (HFSS).