Sequentially rotated polarization conversion metasurface for circularly polarized Fabry‐Perot cavity antenna

Abstract

A sequentially rotated polarization conversion metasurface composed by receiver-transmitter unit cell is presented in this article. The receiver-transmitter unit cell has the capabilities that tuning transmission and reflection coefficients independently, which ensure that the metasurface achieves polarization conversion while maintain its reflection coefficients constant. The transmitter patches of the metasurface are arranged in a sequentially rotated order. Through tuning the sizes of the transmitter patches, equal co- and cross-polarization transmission magnitudes with 90° phase difference are obtained. Then linearly polarized wave is converted to circularly polarized wave. Meanwhile, the metasurface is designed to present high reflectivity, so that it can be applied in Fabry-Perot cavity (FPC) antenna and make the antenna obtain high gain. Combined the polarization conversion capability of the metasurface, the FPC antenna can obtain high gain and circular polarization performance simultaneously. The measured results of the fabricated antenna show that the antenna achieves well circular polarization radiation characteristics. The maximum realized gain of the antenna reaches 17 dBic with in the band of 9.75 to 10.25 GHz. The antenna also achieves well AR performance due to the sequential rotation manner adopted by the metasurface. The AR of the antenna is lower than 3 dB in the band of 9.75 to 10.25 GHz.