A Hybrid Mechanism Water-Based Metasurface for Antenna RCS Reduction

In this article, a water-based metasurface for antenna radar cross section (RCS) reduction is proposed for the first time. The metasurface has a two-layer structure of metal patch and structural water and achieves more than 9 dB RCS reduction in the super high-frequency (SHF) band from 10.6 to 26 GHz based on the mechanism of phase cancellation and wave absorption. Low scattering characteristics are achieved in the X-, Ku-, and K-bands. By using the metasurface as a radiator and introducing a feed structure, a low-scattering antenna in the C-band can be obtained. The impedance bandwidth of the antenna is from 5.7 to 6.07 GHz. The proposed antenna has an extremely small size and low profile, high aperture efficiency, and directional high gain radiation characteristics. Additionally, it exhibits low scattering across a broad frequency band. This work verifies the feasibility of water-based metasurfaces for antenna RCS reduction.