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.