Spectral electromagnetic modeling of a planar integrated structure with a general grounded anisotropic slab

A formulation for the solution of the electromagnetic field in vertically stratified structures with a general anisotropic grounded slab under planar electric excitation conditions is presented. The development of the solution is obtained by using the two-dimensional Fourier transform applied to the partial differential equations describing the electromagnetic field, which can be expressed in terms of dyadic electric Green´s functions. Moreover, a spectral equivalent circuit representation of the solution, separated into its spectral transverse electric (TE) and transverse magnetic (TM) components (with respect to the vertical direction), is given. It is demonstrated that such a spectral circuit representation is always possible when the constitutive ε and μ tensors are reduced to their diagonal form. The transmission-line representation for an unbounded gyrotropic medium with vertical preferred axis is presented. This theory is applied to a planar structure with an anisotropic biaxial grounded slab and an electric horizontal point source embedded in it. Numerical examples of evaluation of the radiated pattern and noteworthy information about the radiation on the horizon plane are given