Multi-Element Phased Array Calibration Method by Solving Linear Equations

In this paper, we propose a new phased array calibration method that measures all antenna element excitations simultaneously. The method has the minimum number of measurements among the known similar methods. The auxiliary antenna used for measurement is placed in either near-field or far-field region to receive the complex array signals during the change of the antenna element phase settings. According to the superposition principle of electromagnetic field, a set of linear equations concerning the element signals are created with the measured array signals. With the scattering parameters between the measurement probe antenna and the element antennas prestored or simplified, we calculate the excitations of the antenna elements by solving the linear equations. The coefficient matrix of the linear equations determines the antenna element phase settings for the array signal measurements. The principles for the selection of the coefficient matrix concerning accuracy, complexity, and hardware requirements are presented. A recursive matrix-forming method is presented for the matrix selection in this paper. Numerical simulations and experiment results validated the effectiveness of the proposed method.