Figure 7. The calculated scattered acoustic field when the acoustic Gaussian beam impinges onto a finite gradient metasurface composed by 18 supercells, each supercell consists of 7 subunits which corresponds to a −1.307 k₀ surface phase gradient.

(a)~(h) are the scattered field when the incident angle is 15°, −15°, 17°, −17°, 20°, −20°, 25° and −25° respectively.