Aperiodic Arrays for Spaceborne SAR Applications

An innovative three-step procedure for the synthesis of linear phased arrays with nonuniformly spaced elements is presented. The main objective is to obtain an array with a minimal number of elements and an optimal efficiency of the amplifiers driving the elements. The procedure consists of three steps. First of all, a periodic array with a single-amplitude tapering and as much phase tapering as there are required shaped patterns is derived. Then, starting from the results of the first step, an equiamplitude nonperiodic array, with a number of phase tapering equal to the number of required patterns and with a minimum number of radiators is synthesized. Finally, a numerical optimization permits refining the results so as to satisfy the design constraints.