Multilayer metasurface-based sandwich composites for wideband radar cross section reduction

Metasurface-based sandwich composites are designed here to achieve radar cross section (RCS) reduction within a wide frequency band. The RCS reduction is realized by spatially arranging the constitutive unit cells with different reflection phases. The proposed composites consist of a metasurface core sandwiched between the glass fiber and carbon fiber reinforced skins. Single-, two- and four-layer metasurfaces are designed respectively to reveal the influence of the layer number on the bandwidth of RCS reduction. It is indicated that the RCS reduction bandwidth can be substantially expanded by increasing the layer number of the metasurfaces. Finally, we fabricate a prototype consisting of four-layer metasurfaces and the RCS reduction property is measured in an anechoic chamber. The experimental results indicate that the fabricated metasurface-based composite can achieve −10 dB RCS reduction from 2.2 to 15.7 GHz, displaying a good agreement with the simulations. It is believed that our proposal may find potential applications in the radar stealth field.