声学超表面的非对称声分束特性研究

非对称声分束超表面是由人工微单元结构按照特定序列构建的二维平面结构,可将垂直入射的声波分成两束传播方向和分束比自由调控的透射波,在声功能器件设计及声通信领域具有广泛的应用前景.本文系统研究了一种实现非对称声分束的设计理论和实现方法,基于局域声功率守恒条件研究了声分束器的设计理论、阻抗矩阵分布、法向声强分布、声压场分布等...

Asymmetric Beam Splitting of Acoustic Metasurface

Asymmetric beam splitting metasurface is a two-dimensional planar structure constructed by artificial micro-unit structures in a specific sequence, which can split the normally incident wave into two transmitted beams with freely modulated propagation direction and splitting ratio. It has broad application prospects in acoustic function device design and acoustic communication field. In this paper, the design theory and implementation method for realizing asymmetric beam splitting were systematically studied. Based on the local power conservation condition, the design theory, the impedance matrix distribution, the normal intensity distribution, and the sound pressure field distribution were investigated. The parameters of four-resonator structures are optimized by Genetic algorithm to realize the required impedance matrix distribution. The sound pressure fields indicate that the surface waves with same amplitude, same attenuation coefficients, and opposite propagation directions are excited at the incident side to match the incident and transmitted local power. The transmitted waves are divided into two beams, the refracted angles and transmission coefficients are in good agreement with the theoretical values, which demonstrate the correctness and feasibility of the design theory and realization method. The research results can provide theoretical references, design methods, and technical support for new asymmetric beam splitting device design, and promote their potential engineering applications.