Design of reflectarray antenna element based on Hour-Glass shaped coupling aperture

Combined with the characteristic of uniformed field distribution in Hour-Glass shaped aperture, the bandwidth of flat reflectarray antenna can be easily widened by using the Hour-Glass shaped aperture-coupled element. The impedance curve and phase response curve of this element are analyzed in this paper. According to analysis, the detail designed parameters of aperture-coupled reflectarray element are proposed. The result shows that 26.6% impedance bandwidth and 1.5 dB gain bandwidth of 23.7% are obtained. In addition, it can provide excellent performance in entire broadband.