EFFICIENT SIDELOBE REDUCTION TECHNIQUE FOR SMALL-SIZED CONCENTRIC CIRCULAR ARRAYS

Abstract

Concentric circular antenna array (CCAA) has interesting features over other array configurations. A uniform arrangement of elements is assumed where the interelement spacing is kept almost half of the wavelength and the array parameters such as the steering matrix and gain are determined. The array performance such as beam power pattern, sidelobe level and beamwidth are discussed in two cases of central element feeding. The two cases are compared showing the reduction in the sidelobe level to more than 20 dB in the case of central element feeding without extra signal processing especially for smallsized arrays that have smaller number of elements and rings.