Frequency Selective Surface Enabled Dual-Wideband Dual-Polarized Reflectarray Antenna with a Large Frequency Ratio

In this paper, we propose a novel approach to realize a dual-wideband dual-polarized reflectarray antenna with a large frequency ratio of 3.5 by realizing and incorporating a frequency selective surface (FSS) into the unit cell and reflectarray design. The proposed FSS realizes reflection amplitude larger than -0.1 dB from 67 to 90 GHz and transmission amplitude larger than -0.88 dB from 20.5 to 27 GHz. This allows the effective upper-band unit cell to be sufficiently and efficiently constructed by the phasing element and the FSS mimicking the ground, and effective lower-band unit cell to be sufficiently and efficiently constructed by 3-by-3 FSS unit cells and the phasing element. The antenna achieves the maximum gains of 34 and 25.7 dBi in the upper and lower bands respectively and 3-dB gain bandwidths from 70 to 88 GHz and 21 to 27 GHz. © 2025 IEEE.