In phased array systems, beam pointing accuracy is one of the major issues for its great effect on radar communication. Regardless of the initial excitation error and the inherent mutual coupling between antenna elements, the anisotropy of antenna element's radiation pattern is the main reason for beam pointing error. In this paper, we propose a closed-form solution of compensating for beam pointing error with uniform linear arrays. It gives a theoretical explanation how beam pointing deviates from the desired angle when scanning angle and the number of elements vary. Then a numerical simulation validates the effectiveness of the proposed theory. Finally, an experiment with an X-band phased array verifies that the closed-form solution can be applied to practical phased array systems in the presence of mutual coupling.

An improved power-only measurement method is proposed to calibrate phased arrays, which is aimed at solving two remaining problems: little contribution of one antenna element’s phase shifting to the whole array’s power and the ambiguity of solutions. The method includes four steps. Firstly, the random distributed phase of each element is adjusted to guarantee that it is −90° to +90° relative to the reference element. Secondly, the proper number of the elements shifting their phases together is approximately determined. Then, an invertible matrix is formed from the standard Hadamard matrix to split the array into different groups, which applies to an arbitrary number of elements; Finally, the array gets calibrated with an existing method. Numerical simulations and experiments are conducted to validate the effectiveness of the proposed method.