Figure 1. Design of the functional acoustic meta-atoms.

(a) Schematic demonstration of the designed subunit sample and a typical supercell consists of 9 subunits. (b) Phase shift values map of the subunits of varying cavity width w and height h. Here, the subunit width P = 15 mm, neck thickness t = 1 mm and neck height H = 19 mm. (c) Scattered acoustic field of a typical set of subunits with a linearly varying phase modulation ranging from 0 to 2π.