Calibration method of mutual coupling in beam forming network for phased-array antennas

To miniaturize the beam forming network (BFN) of the phased-array antenna, high-density integration of the functional components and the transmission lines is necessary. The mutual coupling between the transmission lines due to increased density also increases the array excitation error that degrades the antenna performance. In this paper, a method for measurement of the mutual coupling is presented by detecting the amplitude variation of the BFN output due to rotation of the excitation phase. This method does not need to change the integration condition of the BFN. Also, a method is presented for compensation of the excitation error caused by the mutual coupling. By experiments, the-effectiveness of the methods is demonstrated. (C) 2000 Scripta Technica.