On computation of electromagnetic fields on planar surfaces from fields specified on nearby surfaces

A technique is presented for solution of the inverse problem of calculating the electric field on a planar surface from the electric field specified on a nearby surface. An integral equation is derived that relates two orthogonal components of the electric field on the nearby surface to the respective components of the plane wave spectrum of the planar electric field. The integral equation is solved by an iterative technique, and the planar near field is calculated by an inverse Fourier transform of the plane wave spectrum.