Abstract: The present invention utilizes a calibration signal weight vector as a response vector corresponding to a predetermined orientation angle of the antenna, thereby reducing an interference signal and enhancing a data communication effectively. The calibration method of an array antenna begins with generating a calibration signal in order to measure a transfer function of an array receiving means. A calibration signal vector is injected into the array receiver/transmitter, after multiplying a divided calibration signal and a predetermined weight vector corresponding to each channel together. The divided calibration signal is obtained by dividing the calibration signal by total number of channels. A calibration coefficient is obtained by using that the transfer function of each channel is estimated by analyzing the signal injected from the array receiver or transmitter. Finally, an interference signal is eliminated, by multiplying the received signal of a baseband and the calibration coefficient together.