Development of an allocation method to synthesis of unequally spaced arrays with minimum number of elements and mutual coupling considerations

Abstract

A method is proposed to synthesize unequally spaced arrays so that it has minimum number of elements. Also, it is shown that the proposed method can reduce the total number of elements of equally spaced arrays. The advantage of the proposed method is that it is very fast and straightforward. In this method, the locations of array elements are calculated by considering the mutual coupling between two adjacent array elements, first. After determining the elements locations, two scenarios may be existed. In the first scenario, conventional least square method is proposed. In the second scenario and to increase the accuracy of the final design, recursive least square estimation algorithm is suggested. Mean square error between the desired and synthesized pattern is considered to measure the performance of the method. Several arrays are examined to check the performance of the proposed method. Since, the matrix pencil method (MPM) method has been widely used in the design of nonuniformly spaced arrays, in all examples, the results of MPM technique are considered in comparison process. The obtained results show that the proposed method has a good performance both in reducing the number of array elements and in the accuracy of the synthesized pattern, especially for arrays with beam-shaped pattern such as flat-top and cosecant radiation patterns.