Synthesis of uniformly excited non-periodic antenna arrays: application to microstrip antennas

The authors focus on the synthesis of equally excited arrays obtained by modifying element number and position. The advantage of these arrays resides in the simplification of the feed system. On the other hand, certain constraints arise, due to the fact that the elements cannot overlap. The results were obtained with two types of antenna arrays based on microstrip radiating elements: arrays with nonuniformly spaced elements, and arrays with switched feeding systems. For both types of array, excitation was equal in amplitude and phase. The synthesis of an array of nonuniformly spaced elements consists in determining, for a predefined number of elements, the element distribution yielding a directivity pattern which most closely approximates the desired pattern. This distribution may be either linear or planar. For each of the two types of arrays, a number of different synthesis methods were used. The results of several of these methods are presented.<>