The radiation properties of 2/spl times/2 sequential-rotation arrays with single-feed circularly polarized patch radiators are investigated experimentally with the goal to maximize the bandwidth for an XPD/spl ges/30 dB. Based on a particular cross-polarization discrimination (XPD) description for such arrays, the impacts of element polarization, mutual coupling, limited symmetry, and excitation errors on the array cross polarization are presented. It is shown that compact configurations can be obtained, which provide an on-axis XPD of 30 dB over up to 2.0% bandwidth and of 35 dB over up to 1.0%. These arrays exhibit copolarized sidelobes below -18 dB and off-axis peak cross-polarization levels below -20 dB.
