Experimental verification of a nonredundant NF-FF transformation with spherical scanning for elongated antennas

This work provides the experimental validation of a near field - far field (NF-FF) transformation technique with spherical scanning for electrically long antennas, which requires a nonredundant number of NF data. Such a technique is based on the nonredundant sampling representations of the electromagnetic fields and uses a prolate ellipsoid to shape an elongated antenna. A two-dimensional optimal sampling interpolation formula is employed to accurately recover the NF data required by the classical spherical NF-FF transformation from the acquired nonredundant NF data. It is so possible to obtain a remarkable reduction of the measurement time. Some experimental results, carried out at the UNISA Antenna Characterization Lab and assessing the effectiveness of the proposed technique, are shown.