A SVD algorithm to compensate the probe positioning errors in the spherical NF — FF transformation for quasi-planar antennas

An efficient approach for evaluating the regularly spaced spherical samples from the nonuniformly distributed ones is proposed. It relies on the optimal sampling interpolation algorithm and makes use of the singular value decomposition method to reconstruct the uniformly distributed data, whose position is fixed by a nonredundant sampling representation of the electromagnetic field based on an oblate ellipsoidal modelling of the antenna under test. It is so possible to accurately compensate known positioning errors in the near-field - far-field transformation with spherical scanning for quasi-planar antennas. Many numerical tests have been performed for assessing the effectiveness of the proposed technique.