Single‐Layer Multiple Resonances Metasurface for Polarization‐Independent Broadband Achromatism

Abstract Metasurfaces, owing to exceptional electromagnetic (EM) wave manipulation capabilities, exhibit immense potential and practical value across diverse applications such as imaging, sensing, and communication. However, the inherent dispersion characteristics of most meta‐atoms limit the bandwidth of the devices. While existing methods for bandwidth extension partially address this issue, they significantly increase the design and manufacturing complexity. Here, a dispersion control method is proposed by introducing independent multiple resonant modes with a polarization‐independent single‐layer meta‐atom design, which enables nonlinear phase control over a broadband bandwidth. By compensating for spatial phase delays and implementing achromatic design, the bandwidth of the metasurface can be effectively expanded. As a proof of concept, a broadband achromatic metasurface thin‐film antenna is demonstrated over 4.9–8.3 GHz. Simulation and experimental results indicate that the operational bandwidth of the achromatic metasurface antenna is 2.24 times that of the dispersive metasurface antenna. The proposed single‐layer polarization‐independent broadband achromatism method avoids the multi‐layer alignment problem faced by previous methods and provides a promising avenue for developing lightweight communication and imaging systems.