Simulation of Lüneburg Lens Constructed With Glide Symmetric Periodic Structures

Sammanfattning: The goal of this project was to design a lens utilisinga glide symmetric periodic structure. A Lüneburg lens forantennas with a center frequency of 8 GHz has been designed.The structure was constructed using a unit cell in the shape ofan angular Bowen knot. This unit cell was then etched on themetallic surface of a parallel plate waveguide. Two symmetrycases for the unit cell were studied, the mirror symmetry andthe glide symmetry. Mirror symmetry is when the unit cell wasmirrored on the opposite metallic sheet, and glide symmetrywhen the cell was mirrored and shifted half a period. Theglide symmetric case was found to be less dispersive and moreisotropic. Further, we study the influence on the refractive indexwhen changing the geometry of the unit cell. A sufficient rangeof refractive index for realising the lens was found. These resultswere used to construct a full lens. Simulation of the complete lensshows the desired point to planar wave behavior of a Lüneburglens. In conclusion, the angular Bowen knot with glide symmetryhas the potential to construct a functioning Lüneburg lens.