This study presents a dual-circularly polarized (CP) Fabry–Pérot (FP) antenna, employing a novel receiver–transmitter (RT) metasurface (MS). The RT-MS unit cell consists of two identical neighboring substrates, with a three-layer metal coating printed on their surfaces. The bottom patch is adopted as a receiver to transfer electromagnetic waves to the top-corner cut patch, passing through the coupling cross-slot sandwiched in the middle. The RT-MS has high reflectivity to achieve a high gain. Through energy and a cross-slot, high aperture efficiency can be realized. A conventional corner cut patch can excite a CP mode of equal magnitude and a 90° phase difference. The RT-MS is arranged in 12 × 12 unit cells and used as a superstrate for a dual-CP antenna. Two orthogonally etched slots fed by two branch-matched orthogonally arranged feed lines are used as feeders to produce perpendicular linearly polarized waves. To enhance the bandwidth and improve the gain, double identical stack substrate patches are placed at the top side of the slot with no air gap, for a wide impedance band and high gain. Two wide CP bands, left-hand circular polarization and right-hand circular polarization, of 12.21–13.1 GHz (7.03%) and 12.35–13.1 GHz (5.89%), respectively, have maximum high gains of 16.5 and 15.97 dBic at 12.58 and 12.7 GHz, respectively, with a compact size of 2.6λ0 × 2.6λ0, suggesting better properties than recent antennas. The aperture efficiency can reach 63.2%. Thus, the RT-MS-based FP antenna is a good candidate for commercial and military communication systems.

In this paper, a wideband continuous pure right hand circularly polarized (RHCP), high gain, and low-radar cross-section (RCS) array antenna is proposed. A linear-to-circularly polarization conversion (LCPC) Metasurface (MS) is employed as the superstrate of the Fabry–Pérot (FP) resonator antenna, consisting of two oblique slits etched patches located at top and bottom, respectively, and a metal ring with corner-cutting patch inside, that ensure a wideband transmission and reflection LCPC frequencies ranging from 9 to 22 GHz, and 7–13.5 GHz, respectively. While, a pure RHCP LCPC frequency band of 9–12 GHz is produced by adopt the proposed MS that is benefit from the design of etched oblique slits and corner-cutting patch surrounded by the metal ring, where the magnitude and phase difference can be kept in the variation of ±3 dB and 10°, respectively. Then, a rectangle patch-fed MS FP antenna is designed by an arrangement of 5 × 5 MS unit cells. Following this, the sequence rotated technique is utilized to arrange the array antenna by 2 × 2 units, ensuring a wide band RCS frequency band. The proposed array antenna is fabricated and measured, which indicated the correctness of this design for performance of high gain, low RCS, and wideband pure RHCP. Compared with recent reported MS-based FP works, a wideband LCPC frequencies purity is obtained, and a good radiation and scattering performance is obtained in the design.