On Folded Transmitarray With Dual Polarization

Folded transmitarrays (FTAs)/reflectarrays (FRAs) are effective solutions to reduce antenna profiles while maintaining high-gain performance. Typical folded FTAs radiating to the front with two-thirds profile reduction only achieve single polarization due to the polarization-selective property of the employed grid polarizer. This polarizer reflects one polarization and transmits the orthogonal polarization of the incident wave. In this article, we report a novel dual-linearly polarized (DP) FTA by replacing the grid polarizer with a dual-polarization transmissive metasurface. A DP-FTA that radiates to the backside with half profile reduction (DP-FTA_I) is first proposed. A DP, wide beamwidth, short backfire antenna is designed as the source to eliminate the interference between the backside radiation and the measurement accessories such as the transceiver, feeding cable, and connector. The upper reflective perfect electric conductor (PEC) of the DP-FTA_I is replaced with a DP reflective metasurface for phase compensation, leading to a two-thirds profile reduction (DP-FTA_II). A 16 x 16-element DP-FTA_II prototype is fabricated and experimentally validated, with an aperture efficiency of around 25% and 24.6% at 10 GHz for x- and y-polarizations, respectively. Beam tilting capabilities are also demonstrated using the proposed dual-polarized FTA.