A nonredundant spherical NF-FF transformation using a fast spiral scanning: experimental testing @ UNISA antenna characterization lab

The experimental tests on a near field — far field (NF-FF) transformation technique with spherical spiral scan tailored for quasi-planar antennas are presented in this work. Such a technique is based on the nonredundant sampling representations of the electromagnetic fields and makes use of a very flexible modelling, which allows one to fit a lot of actual antennas by properly setting its geometric parameters. A two-dimensional optimal sampling interpolation formula is then employed to recover the NF data at any point on the measurement sphere and, in particular, at those needed by the classical spherical NF-FF transformation. It is so possible to lower the number of needed measurements, as well as the time required for the data acquisition. Both the reported NF and FF reconstructions assess the effectiveness of the proposed technique.