Broadband and high-quality holographic imaging with complex-amplitude metasurface

Holographic metasurface imaging can reconstruct different types of objects in microwave regions flexibly. In this paper, we present a broadband holographic metasurface that achieves wide bandwidth imaging in the transmission direction. The design is based on a broadband holographic imaging algorithm, which successfully integrates the principles of Rayleigh Sommerfeld diffraction and the broadband wave control principle. After obtaining the E-field distribution of the aperture, the holographic imaging metasurface is built and simulated based on the designed complex amplitude unit. Excited by a typical horn antenna, the holographic imaging metasurface model is then simulated, fabricated, and measured. The measurement results correspond with the simulation results quite well, judging by two distinct images in the X-band (8–12 GHz) and computed correlation coefficients, which mitigate chromatic distortion in holographic imaging under two orthogonal polarization states. Our proposed design holds the potential application value in holographic imaging, information encryption, and multifunctional meta-devices.