5G Millimeter-Wave Reflectarray Antenna Design with a Good Gain-Filtering Characteristic Based on a High-Efficiency Polarization Converter

A shuttle-shaped polarization converter with high-efficiency is designed in the paper, which can operate at 5G millimeter wave and can realize polarization conversion rate (PCR) over 90% from 27.7 GHz to 29.2 GHz. Rotating the polarization converter unit clockwise results in another unit with the same reflection coefficient and a phase difference of 180 degrees. Based on these two units, a high gain reflectarray antenna (RA) with a good and stable gain-filtering characteristic is presented. The maximum realized gain is 23.7 dBi at 28.5 GHz with an aperture efficiency of 17.7 %. For a beam at any angle, the realized gain versus frequency exhibits a a good and stable filter-like curve with a zero.