Array matching by mutual-coupling measurements

The phenomenon of mutual-coupling between the radiating elements of a phased array antenna causes variations both of the excitation distribution over the array and of the input impedances of the radiating elements. These variations are significant in arrays with a small number of elements, arrays with short distances between elements and arrays in the vicinity of which are reflecting bodies. In the past the author has presented a method for beamforming in an active phased array (i.e. for determining its excitation vector) using measured element patterns in the presence of the other elements of the array. The paper presents an expansion of the method taking in account the active mutual coupling. The use of relatively easy to measure values, with no need of complicated theoretical models or too many assumptions in order to calculate the coupling coefficients