A metasurface-based high gain circularly polarized patch antenna with wide global bandwidth

This paper introduces a novel metasurface (MS)-based circularly polarized (CP) microstrip patch antenna. Utilizing a square microstrip patch with plus- and diagonal-shaped slots on a 1.6 mm thick FR-4 substrate as the host antenna, the design incorporates a 4 × 4 square array MS on another 1.6 mm thick FR-4 substrate, separated by a 3.4 mm thick Teflon layer. The antenna offers a −10-dB impedance bandwidth from 5.45 to 7.55 GHz and an axial ratio (AR) bandwidth between 6.02 and 6.35 GHz, achieving a maximum realized gain of 6.3 dBic at 6.25 GHz, exhibiting right-handed circular polarization (RHCP). An equivalent circuit model is developed to validate impedance response, and the fabricated antenna closely matches simulated results. With a low profile of 0.42λo×0.42λo×0.033λo at 6.25 GHz, this CP antenna is suitable for applications like satellite communication for their uplinks and WLAN application.