Patent ID: 8013783

Claim:
A method for estimating the calibration ratio of an active phased antenna having a plurality of phased array antenna elements, the method comprising: injecting an internal calibrating signal having a known amplitude and phase to each antenna element; sequentially 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; correcting for differences in phases and amplitudes of the external calibration signal reaching the antenna elements so as compute an effective signal that would reach all of the antenna elements at zero phase and amplitude differences; calculating complex number calibration ratio as the amplitude ratio and the phase difference of the internal calibrating signal relative to the corrected external calibration signal; and outputting said calibration ratios for said plurality of phased array antenna elements in a form for allowing calibration of the active phased antenna.