Water-based metasurface with continuously tunable reflection amplitude.

In this paper, a water-based metasurface with adjustable reflection amplitude is proposed. The overall structure uses a transparent substrate as a water-based container, and the upper surface is loaded with a double-ring-shaped resistive film. As the height of the water in the container gradually increases from 0 mm to 0.5 mm, within a broadband range from 0.1 GHz to 30 GHz, the maximum adjustable range of the reflection amplitude is -2 dB to -12 dB. The water-based metasurface switches from a state of strong reflection to a state of absorption. The test results are in good agreement with the simulation results. Because the tunable metasurface is transparent to visible light, it can be used for electromagnetic shielding of windows of airplanes.