A new approach for in-situ scan impedance characterization of scanned antenna arrays

Scanned phased array antennas require active scan impedance determination and mitigation. This paper addresses the former by introducing a novel in-situ measurement architecture and associated mathematics for efficiently determining the real-time active scan impedance of arbitrary sized scanned arrays in the field. The in-situ nature of the proposed architecture reduces the need for large numerical simulation and/or estimation of scan impedance variations due to possible diverse antenna array placement in the field. Direct experimental characterization also enables direct validation of numerical simulation. The mathematics developed are for an M by N antenna array utilizing direct in-situ mutual coupling characterization. The mathematical model was implemented in MATLAB and verified through simulation using CST Microwave Studio (MWS) for a 2×2 monopole planar antenna array. The model´s robustness is tested by varying the inter-element spacing.