On the Application of FLO_K and PPTE to Extract the Permittivity and Permeability Tensors of Split Ring Resonator Structures
Recent developments in material parameter extraction techniques have been made, allowing for full tensor extractions of the effective permittivity and permeability of anisotropic materials. This technique, PPTE, requires the use of simulated scattered fields, specifically from FLO K. A rigorous study of the FLO K meshing requirements for resonant structures was conducted, determining that mesh convergence alone was insufficient for accurate solutions, a small floquet aperture standoff was required. PPTE has been validated to extract effective permittivity tensors, but has yet to be validated on magnetic materials, retrieving an effective permeability. Here, the technique was applied to an isotropic medium with defined material parameters and was shown to extract the intrinsic material parameters with a high level of agreement. Next, PPTE was applied to SRRs. Careful consideration of the bi-anisotropic nature of SRRs was considered. PPTE yielded the best results when incident angle was small, thus minimizing any bi-anisotropic effects. However, a comparison of results from PPTE with literature proved inconclusive.