On Measuring the Permittivity Tensor of an Anisotropic Material from the Transmission Coefficients

The permittivity tensor of an anisotropic material can be predicted with use of the presented technique. A slab of this substance possessing infinitesimal thickness is illuminated by a normally incident plane wave and rigorous expressions for the transmission coefficients are obtained. The derived formulas are linearly expanded with respect to the small thickness of the slice, while simple approximations of the material permittivities are produced by measuring the transmission coefficients for suitable polarizations. These simplified expressions provide a physical intuition about the use and the function of the anisotropy parameters which cannot be achieved via more precise but also more complex patterns. Some diagrams of the prediction error with respect to the dielectric constants, the size of the slab and the operating frequency are included and discussed.