Performance investigation of robust concentric circular antenna array beamformer in the presence of look direction disparity

This paper presents the performance of a Concentric Circular Antenna Array (CCAA) with robust optimal diagonal loading (ODL) technique. Because of the symmetrical configuration of a CCAA geometry, it enables the antenna array to scan azimuthally with minimal changes in its beam width and side-lobe levels. The performance of CCAA system is degraded in the presence of disparity between the original signal direction and the steering direction of the beamformer. This performance degradation problem due to look direction disparity can be improved by using robust techniques. This paper proposes the ODL technique for CCAA system and compare the performance of proposed robust CCAA processor with the existing CCAA processors. The proposed robust CCAA beamformer enhances the output power 28.12 dB and 8.624 dB at 2° disparity angle compared to the existing CCAA processor (Hossain et al., 2016) and robust CCAA beamformer (Reza et al., 2016) respectively. Numerical examples are presented to analyze the performance of proposed robust beamformer in different scenarios.