Parallel calibration method for phased array antennas with orthogonal and nonorthogonal codes

In this paper, a parallel calibration method based on the Direct-Sequence Code Division Multiple Access (DS-CDMA) scheme is proposed for satellite-borne phased array antennas. The theoretical analysis of the relationship between the Signal-to-Noise Ratio (SNR) and the calibration accuracy with orthogonal codes is provided in detail. Then we generalize the conventional code-division calibration scheme by suppressing the multiple access interference (MAI) from the use of nonorthogonal codes. Finally, simulation results demonstrate that the accuracy of the proposed calibration method with nonorthogonal codes is in good agreement with that of orthogonal codes and it can reach the theoretical lower bound.