On a closed-form asymptotic Dyadic Green´s function for grounded double-layered anisotropic uniaxial material slab and its application to an efficient analysis of arbitrary microstrip geometries

An efficient closed-form asymptotic representation for the Dyadic Green´s function for the grounded double-layered anisotropic uniaxial geometry is developed. In the present asymptotic development the large parameter is directly proportional to the lateral separation between the source and observation point. The asymptotic solution developed remains accurate even for very small lateral separation of the source and field points. The asymptotic closed-form Dyadic Green´s function has been cast in such a form that the physical behavior of the electromagnetic fields due to anisotropy of the medium reveals itself through simple mathematical parameters. Thus, the physical understanding of the interaction of the spatially confined source with a grounded anisotropic (uniaxial) double-layered material slab is greatly enhanced through the new representation. Also, this representation is very useful in the moment method solution of the current excited on the microstrip antennas and arrays in a grounded double-layered uniaxial geometry, as well as the volumetric current excited within a dielectric scatterer buried in a ground double-layered anisotropic uniaxial slab.<>