Wideband Multifunctional Metasurface for Polarization Conversion and Gain Enhancement

We propose a wideband multifunctional device which combines a linear-to-circular polarization convertor with focusing metasurface. The proposed design is built by a novel dual-layered metal cross and cross ring unit cell which exhibits satisfying performance for controlling the reflecting phase of the electromagnetic wave polarization-independently. The device is illuminated by a Vivaldi antenna, and the functions of polarization conversion and gain enhancement have been simultaneously achieved in the band of 9.12-10.2 GHz. In addition, the polarization helicity of the system can be reconfigured by rotating the feed antenna. The device has not only greatly presented the flexibility and superiority of the metasurface in steering the electromagnetic waves, but also promoted the development of the multifunctional metasurface.