Laboratory testing of an SVD-based approach to recover the non-redundant bi-polar NF data from the positioning error affected ones

This study deals with the problem of the correction of known probe positioning errors, which can occur in an actual planar near-field facility when adopting a non-redundant near-field to far-field (NFTFF) transformation with a bi-polar scan for quasi-planar antennas. To this end, a singular value decomposition based approach is developed to recover the uniform bi-polar samples, whose position is set by the non-redundant sampling representation got by shaping the antenna with a double bowl, from those affected by positioning errors. Then, a 2D optimal sampling interpolation formula is used to accurately reconstruct the plane rectangular near-field data needed by the standard NFTFF transformation from the retrieved non-redundant uniform samples. Experimental results, assessing the capability of the developed procedure to correct even pessimistic positioning errors, are shown.