Phase retrieval antenna diagnostics for bi-polar planar near-field antenna measurements

Phase retrieval methods have just recently evolved into a practical and accurate means for recovering phase information from phaseless near-field antenna measurements. The appeal of phaseless near-field measurements is due to, for example, the inability to accurately measure phase at high frequencies or the prohibitive cost of vector measurement equipment. A phase retrieval algorithm for bi-polar planar near-field measurements has recently been proposed, implemented, and successfully demonstrated using measured bipolar near-field data. In this paper, focus is turned to the antenna diagnostics problem. Measurement results are presented for a waveguide-fed slot array antenna in which an anomaly has been imposed on the aperture distribution. The phase retrieval algorithm reported previously is then applied, with no a priori knowledge of the imposed anomaly, and results are compared to the case when the phase is retained in the conventional near-field data processing.