Asymmetric Beam Splitting of Acoustic Metasurface

Abstract

Abstract: 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.

Key words: asymmetric beam splitting, acoustic metasurface, local power, impedance matrix, resonator

CLC Number:

O422
O424

SONG Ailing, SUN Chaoyu, CHEN Tianning, XIANG Yanxun, XUAN Fuzhen. Asymmetric Beam Splitting of Acoustic Metasurface[J]. Journal of Synthetic Crystals, 2021, 50(7): 1362-1370.

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