A Low-Profile, Circularly Polarized, Metasurface-Based Antenna With Enhanced Bandwidth and Stable High Gain

A low-profile circularly polarized (CP) metasurface-based (MS-based) antenna with enhanced axial-ratio bandwidth (ARBW) and stable high gain is developed. The developed antenna has a stacked layout with the MS containing 3 x 3 patch lattices, which are placed above a custom-designed driven element. The driven element comprises a patch with an etched slot and a parasitic ring strip with shorting pins, which can excite the MS to generate multiple resonances and three AR minimum points, thus resulting in enhancedARBWand stable high gain. Finally, an antenna prototype is designed to confirm the simulation results. The experimental (simulated) results demonstrate that the MS-based antenna is low-profile: 0.03 lambda(0), where lambda(0) corresponds to the operating central frequency at 2.63 GHz, achieving a -10 dB fractional bandwidth (FBW) of 20.48 (19.81)%, and 3 dB ARBW of 10.2 (11)% along with a stable gain of 8.1-8.8 (8.0-9.2) dBic, respectively.