Direct Method for Reconstructing the Radiating Part of a Planar Source from Its Far-Fields

A planar current is generally divided into a radiating part that mainly generates propagation fields and a non-radiating part that mainly generates evanescent fields. This paper proposes a direct method to reconstruct the radiating part of a planar source from its far-fields based on their explicit relationships. A standard reconstruction process is provided in which the far-fields are sampled at the peaks of their propagation modes. An analysis shows that the achievable reconstruction resolution of the source distribution is about half a wavelength. The paper also demonstrates that it is possible to reconstruct the source by sampling the far-fields on a plane or along a linear path. The performance of the reconstruction algorithm is illustrated with numerical examples.