CPW-fed circularly polarized 2/spl times/2 sequentially rotated patch antenna array

A new 2/spl times/2 sequentially rotated circular patch antenna array fed by a coplanar waveguide (CPW)-to-slot lines network is presented. The antenna array is formed on a single layer substrate. The performance improvement by adding the air bridges to the feeding network is investigated. The measured axial ratio and return loss bandwidths are 4.4% and 7.3%, respectively. These properties and its simple structure make the antenna array suitable for mobile communication applications.