Abstract: This paper outlines an effective method to enhance the gain of a microstrip patch antenna while preserving its polarization characteristics. The proposed solution features a double coaxially fed circular radiating slot-patch antenna etched on a dielectric substrate, with a metasurface positioned above as a superstrate. The metasurface presence enables a gain increase of approximately 5 dBi, confirming both Right-Hand and Left-Hand Circular Polarizations (RHCP and LHCP) while ensuring their isolation. The numerical results obtained from accurate full-wave simulations show that the configuration can attain an Axial Ratio (AR) below 3 dB throughout the entire Half Power Beamwidth (HPBW), with a gain of 9.6 dBi at 412 MHz.

URL: https://ieeexplore.ieee.org/abstract/document/10686422