An algorithm for pattern synthesis improvement

When shaped beams are synthesized using array antennas with a limited number of elements, insufficient degrees of freedom sometimes result in practically unsatisfactory patterns. In such cases, it is very convenient if the unsatisfactory patterns can be improved to satisfactory ones using some techniques. An example is presented of such pattern improvement techniques. First, an algorithm necessary for the improvement technique is derived by modifying an algorithm commonly used for adaptive array antennas into a form not requiring real time information of receiving signals. Then, three application examples of this technique are presented. In the example of a shaped beam array antenna of which two elements are removed out of ten elements, measured results are compared to the calculated pattern to show the validity and usefulness of this technique.