Semi-symmetrical Coprime Linear Array with Reduced Mutual Coupling Effect and High Degrees of Freedom

Abstract

Direction finding based on the coprime array has received a lot of interest because of the increased degrees of freedom and larger aperture size compared with the uniform linear array. In this paper, a new semi-symmetric coprime array (SSCA) configuration is proposed to reduce the mutual coupling impact for passive sensing by exploiting the relocation of the redundant elements. First, we examine the difference co-array (DCA) of the prototype coprime array (PCA) and identify the redundant elements. The second subarray (N-subarray) is then split into two subarrays on opposite axis, and the zero-lag location is moved to a new location to construct large contiguous lags in the DCA. The investigation of the SSCA is performed. The analytical expressions of the contiguous lags, unique lags, and aperture size are derived. The numerical and simulation results show that the proposed SSCA array can produce less mutual coupling leakage as compared to other array types