Mechanically Switchable Geometry Phase Metasurfaces For Circular Polarization Antenna Transmission- and Reflection-Wavefront Manipulations

In this study, a novel switchable full-space ABA meta-atom with two modified H-shaped structures combined with frequency selective surface (FSS) units was proposed. We presented a novel method for the design, fabrication, and characterization of switchable metasurfaces, whose radiation direction of modulated circular polarized waves can be easily changed. The novel efficient ABA meta-atom have transmission amplitude of >0.96, reflection amplitude of >0.98, and 2π phase control. A mechanically switchable, high-gain antenna based on the metasurfaces was then developed to validate the proposed design. The antenna functioned as a transmitarray and reflectarray antenna at approximately 10 GHz with 19.1 and 19.5 dBic, respectively, and aperture efficiency of 39% and 42%, respectively. Experimental results of the assembled switchable antenna were in good agreement with the simulated results. The proposed method is promising in many full-space symmetry and chirality devices such as orbital angular momentum generators and holograms.