A Wideband Reflectarray Antenna Employing Novel Phase Delay Line Loading Method

A novel phase delay line loading method for reflectarray antenna (RA) application is proposed in this paper. The subwavelength dimension of the unit is realized by placing the phase delay line underneath the radiation patch to significantly improve the broadband. Furthermore, an additional metal plates is placed between the phase delay line and the radiation patch, which is beneficial to decreasing the coupling and the cross-polarization levels without adopting mirror symmetric arrangement. An experimental RA prototype is designed to verify the concept with the 2-dB gain bandwidth of 22.9%. Additionally, the peak gain of 22 dBi with the aperture efficiency of 55.7% can be achieved by using the ingenious method.