Waves in anisotropic and birefringent artificial dielectrics

The need for light weight multiple beam communication satellite antenna systems has stimulated renewed interest in artificial dielectrics. The particular dielectric studied is comprised of periodically spaced square arrays of thin square metallic obstacles. The major objectives are: to determine why the lenses previously built with this material failed to perform properly; and to design a functional lens if possible. The wave propagation properties of this type of medium are found using a full wave analysis. An equivalent multiport network models the modal conversion at the obstacle plane. An eigenvalue problem is then formulated to determine an effective index of refraction and wave admittance for the periodic structure. These bulk properties are subsequently used to analyze the propagation of a microwave beam incident on a medium. The refraction of a beam through a simple dielectric slab is considered first because one can include the effects of both the multiple internal reflections and the susceptive discontinuities at the boundary surfaces.