Coupling compensation for unmatched circular arrays in high-frequency applications

In this study, the authors perform a complete survey on S-parameter method applications to compensate the coupling effect in circular arrays. The authors illustrate that, despite the simplicity and ease of measurements, the S-parameter algorithm has an adequate performance in comparison with the external calibration techniques in real environments. Based on the simulation and experimental results, for unmatched arrays and low-frequency applications [e.g. high-frequency (HF) radars], the S-parameter method performance is demonstrated to be comparable in accuracy to the external calibration techniques. Despite multipath effect and structural scattering, the direction of arrival can be estimated by the S-parameter method with the same accuracy as obtained by the external calibration techniques, which are disadvantageously location dependent.