Chaos-based coding metasurface for radar cross-section reduction

With the continuous development of chaos research, various chaos models have been explored and applied in interdisciplinary studies. In this work, we propose a coding metasurface based on the spatiotemporal chaos pattern for radar cross-section (RCS) reduction. Here, the mathematical model of FitzHigh-Nagumo chaos is selected to depict the spatiotemporal chaos pattern. The method of 'quantization-coding' is applied. Following the steps of sampling, quantization, and coding, the chaos pattern is associated with 1-bit binary digits '0' and 1', which builds a connection between the chaos pattern and coding metasurfaces. An I-shaped unit cell based on Pancharatnam-Berry phase is designed to assemble the proposed metasurface. As a proof-of-concept, a prototype consisting of 32 x 32 unit cells is designed, fabricated, and measured. Both the simulated and measured results support the feasibility of this study excellently. The RCS achieves more than 10 dB reduction from 10.5 to 20.5 GHz. Significantly, this work provides an alternative strategy to design beam scattering metasurfaces, which may have potential applications for stealth.