High-performance ultra-broadband absorption–diffusion integrated metasurface

We propose an absorption–diffusion integrated metasurface that achieves high-performance stealth of electromagnetic waves with high angular stability in an ultrabroad frequency band. To this end, we designed two types of absorbing meta-atoms with reflection coefficients less than −10 dB in the broadband, which can maintain a phase difference of ∼180° in the range of 5.35–13.5 GHz. Then, the genetic algorithm is utilized to optimize the relationship between the arbitrary coding sequence of meta-atoms and their far-field patterns to obtain the optimal arrangement of the meta-atoms of the metasurface. The simulation and test results of the sample show that the polarization-independent radar cross section (RCS) reduction characteristic over −10 dB in the broadband range (4–18 GHz in simulation and 4.8–16.8 GHz in test) can be achieved. Particularly, the proposed metasurface achieves RCS reduction values over −30 dB in the 7.7–12.4 GHz range. At the same time, the RCS reduction behavior of −10 dB can be maintained to 45° oblique incidence. Experiment and simulation results demonstrate the effectiveness of the present scheme, and the proposed metasurface exhibits better RCS reduction performance than other published literature. This work is of great significance for the rapid design of high-performance absorption–diffusion integrated metasurfaces, which have important prospects in stealth, camouflage, and other related applications.