Uniaxial Anisotropy Estimation of the Modern Artificial Dielectrics for Antenna Applications

In this paper we perform a set of numerical and experimental investigations of the resulting uniaxial anisotropy of the modern artificial dielectrics with antenna applications - rein-forced substrates, 3-D printed and multilayer structures, textile fabrics, some metamaterials, etc. They all usually are mixtures between two or more dielectrics or metals and we estimate their anisotropy using inclusions with different shapes (spheres, cubes, cylinders, disks, etc.) and different dielectric parameters. Experimental data are presented for isotropic polycarbonate sheets with air holes or with surface metal inclusions, for dielectric nets and textile fabrics. Special attention is devoted for determination of the resulting anisotropy in 3-D printed Luneburg lens antennas, fabricated by applying of unit cells with different symmetry.