Design of an All-Metal High-Gain Folded Reflectarray for Mm-Wave Application

This work introduces an all-meta high-gain folded reflectarray antenna (FRA) for mm-wave applications. The proposed FRA consists of a reflectarray aperture and a linearly polarized feed with a wide operating frequency band on the bottom layer, and a simple grid polarizer on the top layer. The simple polarized grid is a single-layer structure consisting of a series of parallel metal strips. The polarized grid has the ability to reflect one linearly polarized wave while transmitting its orthogonal linearly polarized wave. The reflectarray is composed of dual-polarization elements who have excellent orthogonal polarization isolation, and an open-ended waveguide is selected as the feed. According to the results of the simulation, the elements provide a significant phase variation of about 540° with low losses in the 200-240 GHz frequency band. Meanwhile, a wideband FRA with a size of 13.6×13.6 mm is designed and simulated. According to simulation results, the suggested FRA achieves a 3 dB gain bandwidth of 29.5%, a peak gain of 27.8 dBi, and a peak aperture efficiency of 48.4% at 220 GHz.