E.M. Dobychina - C.Sc. (Eng.), Associate Professor of Department of Radiophysics, Antennas and Microwave Technique of Moscow Aviation Institute. E-mail: dem5577@yandex.ru

Since accurate pointing of a beam of a digital antenna array demands precise control of phase and amplitude, exact knowledge of the gain and phase of the electronics is essential. Calibration of a phased array may be accomplished with very little overhead to the service of the antenna. Cycling of the phases of elements through only four orthogonal phases reduces significantly the time for calibration, and use of a maximum likelihood algorithm gives optimal accuracy. Good performance and convergence are obtained for reasonable signal-to-noise ratios and sample sizes.