Coprime L‐shaped array connected by a triangular spatially‐spread electromagnetic‐vector‐sensor for two‐dimensional direction of arrival estimation

The authors propose a hybrid L‐shaped array composed of two sparse scalar arrays and a single triangular spatially‐spread electromagnetic‐vector‐sensor (SS‐EMVS) for two‐dimensional (2D) direction‐of‐arrival (DOA) estimation. These two sparse but uniform scalar arrays are placed along the x ‐axis and y ‐axis, respectively, which constitute two arms of the L‐shaped array. These two arms are connected by an SS‐EMVS, which consists of a spatially‐spread dipole‐triad plus a spatially‐spread loop‐triad. Further, the inter‐dipole/loop spacings of SS‐EMVS follow a coprime relationship with the inter‐sensor spacings of the L‐shaped scalar array. In proposed DOA estimation algorithm, they first perform the vector‐cross‐product algorithm to SS‐EMVS to obtain a high‐accuracy but ambiguous direction cosine estimation; they then apply the ESPRIT algorithm to the scalar array on each arm to get another high‐accuracy but cyclically ambiguous direction cosine estimation; finally, they adopt the Chinese Remainder Theorem to disambiguate the ambiguous estimations. Because the authors’ proposed array has 2D array aperture extension, it can achieve a high angular estimation performance. Moreover, one component of triangular SS‐EMVS rather than an SS‐EMVS is used as the array unit of two scalar arrays; thus, the whole array cost decreases dramatically. Simulation results validate the array configuration and the developed algorithm.