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 of
N
array elements. It comprises the measurement of the array output signal at
M
phase settings applied to the
N
elements involved in the calibration. These
M
phase settings correspond to a linear phase taper that is unique for each of the involved elements and reveals therefore
N
different phase tapers. The complex
M
measurements of the array signal are thought to be the excitation coefficients of a synthetic
M
-element linear phased array. The array factor of this synthetic
M
-element array comprises a superposition of
N
+1 array factors all pointing with their main beam into different directions. By converting this superposition of
N
+1 array factors into a set of
N
+1 simultaneous linear equations, the signals of the
N
individual 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.