A Wideband Circularly Polarized and Beam Deflection Antenna Based on Two Metasurfaces

Scientific research has proved that metasurfaces possess remarkable abilities in controlling the transmission, reflection, and polarization of electromagnetic waves. Here, a coplanar metasurface (CPMS) is proposed to expand the operating bandwidth and axial ratio (AR) bandwidth of a circularly polarized patch antenna. Additionally, another 2-D phase gradient partially reflecting metasurface (PGPRMS) is designed above the Fabry–Perot (FP) cavity. The source antenna consists of a truncated corner square patch radiator and a CPMS, both printed on the same layer. The low profile, circular polarization, wide band, and high gain allow the proposed source antenna to be applied as a standalone antenna. The proposed 2-D PGPRMS is composed of metal rings and metal patches respectively printed on both sides of the substrate. The phase of the electromagnetic wave is controlled for antenna beam steering. Moreover, beam scanning is achieved by rotating the PGPRMS. Simulated and measured results show that the antenna has a wide −10 dB impedance bandwidth of 18.5% (9.3–11.2 GHz) and an overlapping 3 dB AR bandwidth of 9.8% (9.7–10.7 GHz). The beam can be deflected to 58° with a peak gain of 12.3 dBi.