Biomimetic concave basalt fiber-reinforced composite integrating ultra-broadband absorption and excellent mechanical properties inspired by wing scales of butterfly

• • The biomimetic concave basalt fiber-reinforced composite (BC-BFRC) achieves an effective absorption bandwidth (EAB) of 14.7 GHz (3.3–18 GHz) at reflection loss < −10 dB, a 26.7% improvement over planar BFRC, covering 91.9% of the S–Ku band, enabling multi-band radar stealth. • • The composite maintains stable broadband absorption (reflection loss < −8 dB) across incidence angles from 0° to 45° in the 4–18 GHz range, ensuring performance under oblique radar illumination. • • The flexural strength reaches 239.2 MPa, attributed to basalt fiber reinforcement, addressing the mechanical fragility and coating detachment issues of conventional MAMs. • • The broadband absorption mechanism is attributed to impedance gradient between layers and energy capture by the biomimetic concave structure, providing a design blueprint for structure-function integrated MAMs.