Design of a wideband bowtie‐shaped reflectarray antenna loaded with parasitic split rings

Abstract A novel bowtie‐shaped structure loaded with three concentric split rings is proposed for designing wideband reflectarray antenna with low optimizing complexity. The broadband characteristic of the proposed reflectarray element is realized by exciting multi‐resonances through the surrounded concentric split rings. Furthermore, a linear phase curve covering about 700° can be achieved by simply adjusting the flare angle of the concentric split rings. Based on the element, a prototype of the proposed reflectarray antenna with a diameter of 180 mm is simulated and measured. According to the measured results, the peak gain is 22.8 dBi at 10 GHz corresponding to an aperture efficiency of 42%. Besides, 3‐dB gain bandwidth of 28% (8.5–11.3 GHz) is obtained, and the cross‐polarization levels are below −25 dB for both principal planes.