A Planar NF-FF Transformation for Quasi-Spherical Antennas using the Innovative Spiral Scanning

摘要

An effective probe compensated near-field - far-field (NF-FF) transformation with planar spiral scanning, using a minimum number of NF data, has been experimentally validated. It allows a remarkable measurement time saving, due to the continuous movements of the positioning systems and to the reduced number of needed NF data. Such a technique is based on a nonredundant sampling representation of the voltage acquired by the probe, obtained by using the theoretical foundations of the NF-FF transformations with spiral scans for quasi-spherical antennas. Then, the NF data needed by the plane-rectangular NF-FF transformation are efficiently recovered from those acquired along the spiral, via an optimal sampling interpolation formula.