Scattered beam control of encoded metasurface based on near-field coupling effects of elements.

The coupling effect between the element structures of the traditional Huygens metasurface is easy to cause the efficiency of the designed functional devices to be reduced. In order to eliminate or reduce the coupling effect between the element structures, a border-type Huygens metasurface element structure is proposed. In order to confirm that the bounding element structure can significantly reduce the coupling effect, the near-field distribution and far-field properties of two Huygens metasurfaces with and without bounding are compared. Through comparative analysis, we find that the bounding Huygens element structure can significantly reduce the coupling effect between the element structures, and the far-field scattering angle is more consistent with the theoretical calculation value. In order to realize the free regulation of the far-field scattering angle of THz waves, we introduce the Fourier convolution principle in digital signal processing, and operate the element sequence of Huygens metasurface on the addition principle to realize the free regulation of scattered beams. In addition, we performed functional addition operations on the bounding and unbounding coding sequences. The bounding code structure can accurately achieve the synthesis of functions.