Near to far-field plane-polar transformation from probe positioning error affected data

In this article, two efficient approaches for the correction of known positioning errors of the measurement probe in a plane-polar near to far-field (NTFF) transformation, requiring a minimum number of NF data in the case of quasi-planar antennas, are presented and experimentally assessed. Such a NTFF transformation benefits from a non-redundant sampling representation of the voltage detected by the probe got by modeling an antenna with a quasi-planar geometry through a double bowl, a surface consisting of two circular bowls with the same aperture radius, but with lateral bends which may differ to better fit the antenna shape. The uniform samples, i.e., those at the points set by the representation, are accurately retrieved from the collected not regularly distributed ones either by applying a singular value decomposition based approach or an iterative scheme. Then, the input NF data necessary for the classical plane-rectangular NTFF transformation are evaluated from the so retrieved non-redundant uniform samples through a 2-D optimal sampling interpolation formula.