Enhanced microwave absorption and lightweight characteristics via electric-magnetic coupling in Ba₃Co₂Fe₂₄O₄₁@CIP-Filled patch

Microstructure construction and multicomponent strategies are essential for microwave absorption materials, which require a broad effective absorption bandwidth (EAB, RL < −8dB) and thin thickness. Herein, a resin-based patch filled with Ba₃Co₂Fe₂₄O₄₁(Co₂Z) and carbonyl iron powders (CIP) was prepared using air spraying, where the composited absorbent Co₂Z@CIP was synthesized by mechanical ball milling. With the mass percentage of the absorbent fixed at 70 wt%, the influence of the mass ratio between Co₂Z and CIP on microwave absorption was investigated. The composition of Co₂Z and CIP resulted in a significant reduction in magnetic loss and dielectric loss while minimizing the weakening of magnetic polarization, thus facilitating impedance matching. Under these interactions, the resin-based patch with a Co₂Z:CIP ratio of 1:1 realized an EAB of 5.6 GHz (7.4–13 GHz) at a thickness of 1.7 mm, covering the whole X band. Furthermore, the EAB could cover the C2 and Ku bands at the thickness of 2.1 mm and 1.3 mm, respectively. RCS simulation demonstrate the excellent signal suppression within a wide range of incident angles. The design strategy effectively meets the requirements of modern radar stealth.