Closed Form Characterization of Mutual Coupling in Uniform Linear Arrays

This paper proposes a pragmatic methodology to characterize mutual coupling in uniform linear arrays (ULAs). The classical coupling model used in the literature of multiple input multiple output (MIMO) antenna arrays is based on impedance parameters, resulting valid only for electromagnetically small antennas, e.g. short dipole. To test the robustness and accuracy of the proposed coupling model we consider ULAs with different antenna types and number of elements. We provide closed form expressions for the mutual coupling characterization of the studied ULAs, which are then used to evaluate the spectral efficiency performance of a MIMO cellular system. Our results show that the proposed method can provide more accurate characterization of the studied mutually coupled ULAs and hence better estimation of the spectral efficiency in comparison to the classical method.