Experimental Assessment of a Non-Redundant Approach to Minimize Data in a Spherical NF-FF Transformation for Offset Mounted Elongated AUTs

This work concerns the experimental validation of a near-field (NF) spherical scanning for an offset mounted long antenna under test (AUT), that requires a non-redundant (NR), namely minimum, amount of NF data. We address the issue of decreasing the number of voltage samples required to execute the traditional NF-far-field transformation (NF-FFT) technique in a non-centered case scenario, which would generally need a considerably higher amount of input data as compared to the onset case. In particular, by exploiting the theory of the NR sampling representations of electromagnetic field and adopting a rounded cylinder model of the antenna, the number of required samples is exactly the same as the minimum one involved in the onset scenario. Experimental results, which prove the goodness and efficacy of the approach, are presented.