Broadband Circularly Polarized Antenna Using Metasurface for 5G Applications

Using an aperture coupled microstrip antenna (ACMA) as source antenna and a linear-to-circular polarization converter metasurface (PCM) as superstrate, a miniaturized planar broadband circularly polarized (CP) antenna with unidirectional radiation characteristics is designed. The metasurface is composed of metal rectangular periodic unit cell arrays with an inclination of 40 degree. RO4003 are used as substrates of the proposed antenna. The −10 dB impedance bandwidth is 44%, ranging from 4.6-7.2 GHz, and the CP operating bandwidth is 21.5%, ranging from 5.8-7.2 GHz, covering the 6GHz band (5925–7125 MHz) of 5G applications. Besides, the proposed antenna has good gain stability over the CP operating bandwidth, and the maximum gain of 8.5 dBi is achieved at 6.9 GHz.