All-metal coding Metasurface for broadband radar scattering control and SAR image camouflage

Radar signature manipulation materials, such as radar-absorbing structures, have attracted broad interest for regulating the electromagnetic scattering characteristics of complex targets. However, most existing functional materials rely on dielectric or composite systems, which can limit environmental adaptability, durability, mechanical strength, and conformal integration. Low-cost solutions capable of achieving broadband scattering control and radar image signature regulation remain insufficiently explored. In this paper, a conformal all-metal coding metasurface is proposed to realize electromagnetic scattering suppression and cooperative control of radar image signatures using metallic structures. Two all-metal unit cells with an approximately 180° reflection phase difference are designed to enable broadband phase modulation from 10 to 18 GHz. By optimizing the coding sequence, the metasurface redistributes backward scattering energy and achieves broadband radar scattering reduction. In the X-band, an 8 × 8 coding array is employed to manipulate radar image signatures and generate preset illusion features. Owing to its substrate-free architecture, the proposed metasurface can be integrated with impact-resistant skins through advanced 3D printing for monolithic fabrication. This work expands the design space of electromagnetic scattering control materials and offers a promising route toward multifunctional protective structures in complex electromagnetic environments.