Design of a Wideband 1-Bit Metal-Only Reconfigurable Reflectarray Antenna

A 1-bit metal-only reconfigurable reflectarray antenna is proposed in this work. The element of the reflectarray antenna is a 3-D structure composed of a rectangular base, two orthogonal metal plates. By setting two cylindrical slots of different sizes on these two plates, 180° reflected phase difference of two orthogonal linearly polarized waves is obtained. By rotating the proposed element by 90°, the 1 -bit reflected phase can be achieved. Then, a $40 \times 40$ element reflective aperture spatially fed by a horn antenna is designed and simulated. The beam-scanning of the presented reconfigurable reflectarray antenna can be realized by rotating the elements on the reflective aperture. In simulation, a peak gain of 27.3dBi at 10GHz corresponding to an aperture efficiency of $29.0 \%$ are obtained. Furthermore, the maximum gain drop within 60° beam scanning range is $4.0 \mathrm{~dB}$ at 10.0GHz while the maximum beam pointing errors is only 1°. These results indicate that this reflectarray antenna has the advantages of high efficiency, wideband and high stability.