Sparse linear array with low mutual coupling ratio for DOA estimation

Abstract

In order to reduce the mutual coupling ratio of sparse linear array, a new linear array structure with two sparse uniform linear arrays interleaved nested, is proposed in this paper. The new sparse linear array structure is consisted of two subarrays which have N and M physical sensors, respectively. By setting appropriate interelement spacing and interleaving, the degrees-of-freedom, uniform degrees-of-freedom and array aperture of the proposed sparse array can reach 2NM + 2N , 2(N + 2M) + 1 and max{(N − 1)R 1 , (M − 1)R 2 + d }, respectively. On one hand, the proposed sparse array has closed-form expressions for the sensor locations. On the other hand, through comparative analysis, although the proposed array structure has lower uniform degrees-of-freedom, it can greatly increase the degreesof-freedom, extend the array aperture, and reduce the mutual coupling ratio between physical sensors, which means better estimation performance of direction-of-arrival estimation can be achieved. Finally, the direction-of-arrival estimation performance of the proposed array structure is verified by numerical simulations. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Symmetric thinned coprime array with reduced mutual coupling for mixed near‐field and far‐field sources localization

“…Generally, the array sensor spacing has a great influence on the mutual coupling effect [25]. The larger the inter-sensor spacing, the lower the mutual coupling effect [26,27].…”