Beam-pattern Control via Thinned Elements Strategy in Linear and Planar Phased Arrays

Abstract

|Recon(cid:12)gurable antenna arrays play a major role in the current and future wireless communication systems due to their multifunctional capabilities and many other advantages. Conventionally, the array pattern recon(cid:12)gurations were usually achieved by controlling the excitation amplitudes and phases of all or most of the array elements which are generally costly and complex methods. In this paper, a simple method for controlling the recon(cid:12)gurability of the beam-patterns of linear and planar arrays is presented. It can be easily switched between narrow and wide beams using thinned elements strategy. First, the array elements are divided into three groups based on their locations namely central, middle, and outer elements. Their amplitude weights are chosen to be unity, adaptive, and zero, respectively. To add some desired constraints on the array beam-patterns such as limited sidelobe level and speci(cid:12)ed nulls placement, the excitation weights of the middle elements are optimized such that an abrupt change in the array taper is avoided. This also avoids an undesired change in the sidelobe pattern. A genetic algorithm is used to perform such optimization so that the produced beam-patterns are best matched to the desired ones. Moreover, the size of the thinned region controls the resulting beam width.