Positioning errors compensation in a nonredundant spherical NF-FF transformation: experimental evidences

An effective technique to compensate the positioning errors in a spherical near-field – farfield (NF–FF) transformation for quasi-planar antennas is proposed and experimentally validated. It relies on a nonredundant sampling representation of the voltage measured by the probe obtained by adopting a very flexible antenna modelling. The singular value decomposition method is applied to retrieve the NF data at the points fixed by the sampling representation from the acquired nonuniformly spaced ones. Once the uniform data have been recovered, those needed by the classical spherical NF–FF transformation are efficiently evaluated by using an optimal sa mpling interpolation algorithm.