Figure 9.

(a) The structure of the coding metasurface. The relationship between the reflection phase, the reflection coefficient, and the neck width w₁ (b) and w₂ (c) of the two subunits at f₁ and f₂. Reproduced with permission from [88]. Copyright © 2021, Elsevier. (d) The structure of the coding metasurface unit. The reflection phase (e) and reflection coefficient (f) change with the length d of the neck side in the structure. Reproduced with permission from [89]. Copyright © 2019, AIP Publishing.