一种基于旋转测量的阵列幅相误差校正新方法

A New Rotation Measurement-based Method for Array Gain-phase Errors Calibration

校正源信号方向角不容易精确测量,限制了阵列有源校正方法的精度。另一方面,无源校正方法难以应用于存在大阵列误差的场合,其实际应用也受到严重限制。该文提出一种基于旋转测量的阵列幅相误差校正新方法,无需测量校正源信号方向角就能获得较高的校正精度。该方法利用已知的阵列旋转角度,基于最大似然准则获得阵列幅相误差、校正源信号方向角及其复振幅的无模糊估计。相对于校正源信号方向角,阵列旋转角度通过专用测试转台更容易精确测量,因此该方法能以较小的代价获得很高的校正精度。仿真实验验证了该方法的有效性和通用性。

It is not easy to accurately measure the direction angles of calibration-source signals, which limits the precision of array active-calibration methods. On the other hand, passive-calibration methods are difficult to apply to the presence of large array errors, which severely limits their practical applications. This paper proposes a rotation measurement-based method to calibrate array gain-phase errors, which can achieve high calibration precision without measuring the direction angles of calibration-source signals. Using the known array-rotation angles, the maximum likelihood-based method is able to simultaneously estimate the array gain-phase errors, direction angles and complex amplitudes of calibration-source signals without ambiguity. Compared with accurately measuring the direction angles of calibration-source signals, accurately measuring the array-rotation angles is much easier to be accomplished with a special test turntable, thus the proposed method can achieve quite high calibration precision at a low cost. Some simulation tests demonstrate the effectiveness and generality of the proposed method.