Antenna Beamforming With Feedback Phase Control and a Study on the Control Stability

ABSTRACT An antenna beamforming system with feedback phase control is proposed, and an analysis of the control stability is described. When the number of the antenna elements is two, the phases are controlled depending on the residual phase difference of the signals. It can be realized with a simple feedback system. When the number of the antenna elements is more than two, there are plural phase differences, and plural control loops are required. It makes the stability analysis complex. In this paper, a control system with small number of feedback loops is proposed, and an analysis method with eigenvalues of the transfer matrix is described.