Ultra-wideband metasurface with linear-to-circular polarization conversion of an electromagnetic wave

An ultra-wideband metasurface with characteristics of linear-to-circular polarization conversion is proposed in this paper. By virtue of the metallic vias and multireflection, the proposed polarization convertor can convert the y (x) polarized electromagnetic (EM) wave to a circularly polarized one after reflection in an ultra-wide frequency band. Simulated results show that the proposed polarization convertor can perform nearly perfect linear-to-circular polarization conversion at five frequency points and achieve a 3-dB axial ratio (AR) in the frequency range of 4.7-21.7 GHz at normal incidence. Reasonable agreement between the experiments and simulations has been obtained. Due to the advantage of the scalable geometry of the proposed metasurface, it is a good candidate to be used for manipulating the polarization states of EM waves from radio to optical frequencies. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.