Phased array antenna having integral calibration network and method for measuring calibration ratio thereof

A calibration ratio calculation system for use in calibrating a phased array antenna arrangement having a first plurality of phased array antenna elements connected to a second plurality of receiving channels, an integral calibration signal injection network for injecting respective calibration signals to each antenna element and an amplitude and phase measurement unit for measuring respective signal amplitude and phase for each antenna element, a probe for disposing in the near field of an aperture of the phased array antenna arrangement for injecting an external calibration signal from a stationary RF-source to all of the phased array antenna elements so that different phases of the external calibration signal arrive at each of the antenna elements;

• a signal correction unit for computing and applying a respective phase difference and amplitude difference to the respective external calibration signal for each antenna element so as to obtain a corrected external calibration signal at all of the antenna elements whose phase difference and amplitude difference is zero;
• and
• a calibration ratio processing unit coupled to the signal correction unit for calculating a complex number calibration ratio as the amplitude ratio and the phase difference of the internal calibrating signal relative to the corrected external calibration signal.