Tunable annular acoustic metasurface for transmitted wavefront modulation

Abstract

We propose a tunable flat acoustic metasurface which consists of fan-shaped tunable annular resonator arrays. The volume of the annular resonators can be adjusted by rotating the outside shell. Compared to existing tunable metasurfaces, it is capable of providing effectively transmitted wavefront modulation in a wide frequency range. We present the details of the acoustic metasurface design, and numerical simulation demonstrates the tunability of the wavefront modulation, and acoustic focusing at different focal spots in varying frequency. The presented tunable annular metasurface broadens our horizons to developing tunable metasurfaces of transmitted wavefront modulations.