A Wideband All-Metal Folded Reflectarray Antenna Using a Novel Grid Polarizer

This work presents a wideband all-metal folded reflectarray antenna using a novel grid polarizer. The proposed folded reflectarray antenna consists of a horn antenna for feeding, a reflective aperture composed of 35 × 35 reflective elements, and a novel grid polarizer capable transmit a linearly polarized wave while reflect its orthogonal polarized wave. The reflective element with a subwavelength is made up of two orthogonal rectangular metal plates etched with two trapezoidal slots, which allows to independently control orthogonal polarized waves. Then, a large smooth phase variation of 670° is achieved by varying the lengths of the slots. The element of the novel grid polarizer is designed as triple-layer rectangular metal patch etched with three parallel slots and one vertical slot. The simulated results show that the polarization selection bandwidth of the proposed grid polarizer reaches 53.5%. Then, a wideband all-metal folded reflectarray antenna in X-band is designed and simulated to verify the performance. The simulated results demonstrate that a peak aperture efficiency of 54.1% and a 3-dB gain bandwidth of over 34.2% are obtained.