Autocalibration algorithm for mutual coupling of planar array

Abstract

With few exceptions, high resolution direction of arrival (DOA) estimation algorithms suffer a lot from the mutual coupling between different array elements. In order to compensate this effect, two autocalibration methods are proposed for the 2-D DOA estimation on a planar array. Both of them can estimate the DOAs without any iterative process or calibration sources. We prove that the effect of mutual coupling can be automatically eliminated by the inherent mechanism of the proposed methods. Moreover, they can also achieve an obvious performance improvement even when there is a coupling model mismatch. After getting the DOA estimations, two methods are proposed to estimate the mutual coupling coefficients. Moreover, these coefficient estimates can be used to further improve the accuracy of DOA estimations. The Cramer–Rao lower bound (CRB) for the parameter estimations are also presented as the benchmark. Simulation results demonstrate the effectiveness of the proposed algorithms.