Improved Multilayer Thin Dielectric Sheet Approximation for Scattering from Electrically Large Dielectric Sheets

An improved scheme of the multilayer thin dielectric sheet (ML-TDS) approximation is proposed in this letter to analyze scattering from electrically large dielectric sheets. Benefiting from a more effective expression for normal components of the volume current than that in the original ML-TDS model, the maximum thickness of solvable dielectric sheets is increased from 0.2 dielectric wavelength to at least 0.35 dielectric wavelength, without decreasing the solution accuracy and increasing the unknowns. Moreover, the phase extracted (PE) basis functions are first introduced to express the volume current in the dielectric sheet, and the number of unknowns is reduced dramatically. Compared to the original ML-TDS model using traditional basis functions, the improved approach can be applied to analyze the sheets with a much larger (lateral) size and thickness. Numerical examples demonstrate the good accuracy and much higher efficiency of the proposed solution.