Efficient Calculation of Electromagnetic Characteristics of 2-D Periodic Dielectric Objects Above Half-Space

An efficient mixed-potential integral equation formulation is proposed for the analysis of 2-D periodic dielectric objects above the half-space. The spatial-domain half-space Green's functions are obtained from the corresponding spectral-domain Green's functions via the discrete complex image method (DCIM) combined with the matrix pencil method (MP) technique. Then, the Poisson summation formula is used to express the periodic Green's function via a combined summation of spectral and spatial terms. However, the half-space Green's function with 2-D periodicity is commonly expressed as spatial and spectral infinite series that leads to bad convergence. In order to effectively calculate the components of dyadic and scalar mixed-potential half-space periodic Green's functions, a novel acceleration method is proposed. In this work, the modified Ewald method is applied to the spatial series to accelerate periodic Green's functions convergence. Numerical results are provided to validate the efficiency of the proposed method. Compared with the traditional spatial method, the accelerated algorithm has faster convergent speed.