Fast and Accurate Array Calibration Using a Synthetic Array Approach

A new method for the calibration of arrays is presented that allows the simultaneous calibration ofNarray elements. It comprises the measurement of the array output signal atMphase settings applied to theNelements involved in the calibration. TheseMphase settings correspond to a linear phase taper that is unique for each of the involved elements and reveals thereforeNdifferent phase tapers. The complexMmeasurements of the array signal are thought to be the excitation coefficients of a syntheticM-element linear phased array. The array factor of this syntheticM-element array comprises a superposition ofN+1 array factors all pointing with their main beam into different directions. By converting this superposition ofN+1 array factors into a set ofN+1 simultaneous linear equations, the signals of theNindividual elements to be calibrated including the combined signal contribution of the static elements, can be solved by standard matrix inversion techniques. Computer simulations are presented to demonstrate the capabilities of the new calibration method.