Design and Broadband Absorption Performance of a Continuous Fiber <scp>3D</scp> ‐Printed Graded Metamaterial Structure

ABSTRACT To address the increasing demands for integrated stealth and load‐bearing functions in modern aircraft and communication systems, this study develops a novel multilayered absorber (MA) utilizing a continuous fiber 3D printing process. This structure features a three‐tiered graded metamaterial structure (3T‐GMMS) as the microwave absorbing core layer. Benefiting from the concentric square spiral distribution of carbon fiber (CF) and a dual‐gradient design (both intra‐layer and through‐thickness), the MA exhibits excellent TE/TM polarization insensitivity and oblique incidence stability. It achieves an average absorptivity exceeding 0.9 within the 4–18 GHz frequency band, with an effective absorption bandwidth (EAB) surpassing 13 GHz. Regarding mechanical performance, in‐plane compression tests demonstrate that continuous fiber‐reinforced (FRP) specimens achieve an ultimate edgewise compressive strength of 128.78 MPa, representing a 27.06% increase over pure polylactic acid (PLA) specimens. The design and fabrication of these 3D‐printed graded metamaterial structures offer a promising strategy for developing integrated structures that balance superior microwave absorption performance with robust load‐bearing capacity.