Realization of Acoustic Lens Realized with a Bending Waveguide

In this study, a high-transmission acoustic bending waveguide structure is designed to achieve precise control of the phase and amplitude of transmitted waves. The bending waveguide structure consists of two pairs of straight tubes and three circular arc tubes, enabling accurate wavefront manipulation by adjusting the length of the straight tubes at the neck of the bending waveguide. Through numerical simulations, the bending waveguide structure is analyzed and optimized. The phase is uniformly divided into eight parts, with eight unit cells covering the full $2 \pi$ range. According to the theoretical calculations, these eight unit cells are flexibly combined to construct a metasurface that can realize an acoustic lens with functionalities such as focusing, beam splitting, and cloaking. This designed acoustic bending waveguide structure provides a new approach for three-dimensional acoustic wave manipulation.