Numerical and Experimental Assessment of Source Reconstruction for Very Near-Field Measurements With an Array of $H$ -Field Probes

This paper presents a novel formulation of the source reconstruction problem that aims at increasing the accuracy of near-held (NF) to far-held (FF) transformations in a particular measurement arrangement, where the NF data are rapidly acquired by a planar array of H-held probes located close to a ground plane. A source reconstruction algorithm is proposed for obtaining the near electric and magnetic helds as well as the FF radiation pattern of the antenna under test after hltering the effects of the currents induced on the ground plane backing the probe array. This algorithm exploits a system of integral equations that, after discretization according to the method of moments, enables backprojecting the measured helds on equivalent sources distributed over an arbitrary 3-D surface. Different integral equations are considered for that purpose. The accuracy provided by four different integral formulations is investigated from measured and synthetic experimental data and compared with the standard plane wave spectrum reconstruction technique, making it possible to arrive at a conclusion as to which one to use in order to make the hnal analysis.