FFT-JVIE algorithm for computation of electromagnetic fields in inhomogeneous dielectric objects

An FFT-volume integral equation formulation based on equivalent polarization currents is presented for the analysis of inhomogeneous dielectric objects. The Galerkin discretization scheme used herein incorporates piecewise constant functions and results into well-posed systems even for scatterers of high contrast. Moreover, the original 6-D (volume-volume) Galerkin inner products are reduced to 4-D (surface-surface) integrals, allowing existing algorithms to compute with high accuracy the pertaining singular multidimensional integrals. Finally, the resulting numerical system is solved by means of iterative methods and the convergence is accelerated with the help of an analytical preconditioner.