Computation of electromagnetic wave scattering from an arbitrary three-dimensional inhomogeneous dielectric object

A scattering matrix formulation for scattering of electromagnetic fields by an arbitrary three-dimensional dielectric objects is presented. It is based on an extended moment method that digitizes the scattering equation by dividing the scatterer as well as the measurement region into small cells. The Green´s function within each cell is derived analytically by integrating over the cell. The accuracy of the method is demonstrated by computing vector scattering fields from a uniform dielectric sphere and comparing the results with those calculated using the Mie scattering formula. The formulation also provides an inverse solution, namely, determination of the dielectric profile of the scatterer from the scattering field measured in a finite region outside the scatterer