Switchable bi-functional water-based metasurface for high efficiency and wideband polarization conversion and absorption

A reconfigurable metasurface with a switchable function, wideband, and high efficiency has gained a lot of attention for the creation of compact and efficient devices. Here, for the first time, we propose a bi-functional metasurface that utilizes a water-based resonator to achieve wideband and high-efficiency absorption and cross polarization conversion in the microwave range. By controlling the water injection, the functionality of the metasurface can switch between absorption and cross-polarized conversion. Via water injection, the designed water-based metasurface can act as a wideband absorber with an absorptivity of above 90% in the broadband range of 16.5-24 GHz. Meanwhile, without water injection, it exhibits the ability for high efficiency cross-polarization conversion across a wideband in the range of 4.38-11.9 GHz. The proposed metasurface is fabricated and measured to verify its ability to switch between the dual functions of high efficiency wideband absorption and cross-polarization conversion. We believe that the metasurface platform shown here will open up new possibilities for creating compact multifunctional devices for applications in the microwave region.