Effective mutual coupling estimation and calibration for conformal arrays based on pattern perturbation

Processing conformal array signal is sensitive to antenna patterns on horizontal (H) and vertical (V ) planes while mutual coupling (MC) impacts distinctly on them. Many existing MC calibration algorithms ignore that and thus lose their efficacy. In this study, MC is modelled as distortions of H and V patterns. The direction-dependent and slowly varied properties indicate that MC can be estimated via sampling in the interested spatial range and calibrated. A novel MC estimation and calibration algorithm for all kinds of conformal arrays is proposed based on it. The process requires the use of three signals with diverse sets of polarisation emitted by a known calibrated source in each sampling direction. The selection of diverse polarisations is analysed in terms of optimisation and practical application. Simulations exhibit the potentialities of the proposed algorithm regarding the precision of MC estimation and the efficiency of calibration. It shows that significant superiority influences greatly in the analysis of conformal arrays.