Sectorized approach and measurement reduction for mutual coupling calibration of non-omnidirectional antenna arrays

Mutual coupling calibration is an important problem for antenna arrays. There are different methods proposed for omnidirectional antennas in the literature. However, many practical antennas have non-omnidirectional (NOD) characteristics. Hence, the previous mutual coupling calibration methods cannot be applied directly since the mutual coupling matrix of an NOD antenna array has angular dependency. In this paper, a sectorized approach is proposed with a transformation matrix for mutual coupling calibration of NOD antenna arrays. In addition, the symmetry of the array radiation patterns for the symmetric array elements is used to reduce the number of calibration measurements. A novel antenna is used to show the accuracy and performance of the proposed approach in direction finding problem where numerical electromagnetic simulations are used to obtain the simulation data.