A Metasurface-Based Low-Profile Circularly Polarized Antenna with Double-Wide Beam for Global Navigation Satellite System.

This study introduces a metasurface-based low-profile circularly polarized (CP) antenna with double-wide beam for global navigation satellite systems (GNSSs), which covers primarily BDS-2 B1 band and BDS-3 B1 band. At first, a T-slot structure achieving a compact design is presented to effectively miniaturize the antenna. Except that, a gear-type parasitic ring and eight parasitic microstrip lines are proposed to broaden both the half power beamwidth (HPBW) and axial ratio beamwidth (ARBW) of the antenna. Furthermore, a metasurface unit featuring double "WIFI" logo structure is introduced. This unit is expanded into a 7 * 7 metasurface loaded under the antenna, significantly improving its radiation characteristics. After experimentation, the proposed antenna achieves notable results: 121° HPBW and 214° 3 dB-ARBW at 1.561 GHz and 121° HPBW and 236° 3 dB-ARBW at 1.575 GHz. Additionally, it demonstrates more than 3.52 dBic gain across the whole frequency band, whose simulation and test results are in agreement. These results show that the antenna can be used for various satellite communication systems necessitating CP antennas with wide ARBW and HPBW. [ABSTRACT FROM AUTHOR]