SEDNA: An Improved Sparse Array Design for Reduced Mutual Coupling and Enhanced DOA Estimation Accuracy

The super enhanced dilated nested array (SEDNA) is a new improved sparse linear array (SLA) design that is achieved by hole filling, adjusting the inter-sensor spacing (ISS), and splitting the array. The proposed SEDNA utilizes the ISS of the conventional enhanced dilated nested array (EDNA) for adjusting and does not require additional sensors. Compared with existing dilated nested array (DNA) derived arrays, the SEDNA has fewer pairs of small ISS physical sensors and therefore has lower mutual coupling (MC) effects. Meanwhile, a hole-filling strategy utilized by this array to migrate dense subarray elements greatly enhances its uniform degrees of freedom (uDOF). Moreover, rigorous closed-form expressions for all sensor positions, attainable uDOF and weight functions for the six uniform linear arrays (ULAs) in the SEDNA are demonstrated in detail. Numerical experiment results demonstrate the advantages of the SEDNA array.