DESIRABLE ILLUMINATIONS FOR CIRCULAR APERTURE ARRAYS

The design of phased-array antennas has progressed to the point where side-lobe control is limited by practical problems of aperture efficiency and element tolerances. So far as the theoretical limits are concerned it is possible to provide a variety of designs meeting any side-lobe specification desired. This being the case, it becomes desirable to examine the requirements for low side lobes more critically. In particular, it is felt that more attention should be given to desirable relations between the average side-lobe level and peak side-lobe level. To provide some insight into the type of pattern control that is possible, numerical calculations have been made for a variety of illuminations having the same aperture efficiency. It is shown that by allowing the peak side lobe to increase slightly, important improvements can be made in the level of the more remote side lobes