Direction-Finding With Spread Array of Identical Doublets

In this letter, we present a fully sparse array geometry termed as Spread Array with Identical Doublets (SAID) for high accuracy direction-finding and mutual coupling effect reduction. In SAID configuration, the distances of two adjacent doublets and between two components of a doublet are all set to be larger than a half-wavelength. A direction estimation algorithm is further derived to yield unambiguous source direction estimates to make the SAID array configuration practically feasible. Numerical examples are finally provided to justify the SAID in terms of the estimation accuracy improvement and the mutual coupling reduction, by using a practical mutual coupling model.