Absorptive‐Diffusive Metasurface for Ultrawideband Backscattering Reduction

In this article, an absorptive‐diffusive metasurface is proposed, which realizes wideband radar cross section (RCS) reduction by hybridizing diffusion and absorption at low and high frequencies, respectively. The combination of artificial electromagnetic (EM) metasurfaces with absorbing materials creates new design paradigms and research avenues for RCS reduction. The proposed absorptive‐diffusive metasurface is a three‐layer structure. The top‐layer miniaturized coding metasurface utilizes EM cancellation to reduce low‐frequency backscattering. The middle layer is a lossy layer which, together with the conducting reflective plate, can form a circuit analog EM absorber. The bottom layer consists of two absorbing materials backed by a conducting reflective plate. The middle and bottom layers work together to absorb high‐frequency EM waves. Miniaturized and absorptive elements are utilized by the coding metasurface to suppress harmonic resonance at high frequencies. Through combined absorption and diffusion, this proposed metasurface achieves a 10 dB reflection reduction in an ultrawide range from 1.79 to 30 GHz. Experimental results demonstrate a significant reduction in EM backscattering across the ultrawide frequency band of 1.85–30 GHz, with polarization‐insensitive behavior. Furthermore, the measured RCS reduction remains stable under oblique incidence, achieving angular stability up to 30°. These findings show excellent agreement with simulations.