散射体旋转诱导模态下拓扑声高性能波束成形机理

Topological Acoustic High Performance Beamforming Mechanism Under Scatterer Rotation-Induced Mode

实现具有特定形式的无旁瓣高指向性声波波束的发射以及发射器件抵抗错误因素的能力过低一直是波束成形领域的棘手问题,通过旋转散射体在声学拓扑绝缘体的体边对应关系下提出了散射体旋转诱导模态下拓扑声学高性能波束成形机理。受到旋转散射体对模态耦合的调控,能够实现无旁瓣宽频段下对波束波峰宽度以及波束能量衰减速率的近场和远场调控。通过在此结构内部引入错误因素,发现此拓扑声学高性能波束成形器具有高容错特性,多个错误因素对波束成形的近场远场结果基本不产生影响,这在很大程度上降低了加工制造的难度,同时极大地提高了器件的使用寿命。分别对拓扑声学波束成形以及错误因素介入下波束成形进行了实验验证,实验测试结果实现了4100~4630 Hz宽频带下无旁瓣的宽波峰波束,并且在器件中部分散射体缺失的情况下充分验证了波束成形器的高容错性。该研究提出的全新波束成形方法可为声学通信、微纳制造、生物医学和其他微形及多功能声学设备的工程应用提供参考。

The emission of high directional acoustic beams without sidelobes,along with the low resistance of transmitting devices to error factors,has been a challenging issue in beamforming.In this paper,a mechanism of topological acoustic beamforming with high performance under rotation-induced mode of the scatterer is proposed under the bulk-boundary correspondence relationship of the acoustic topological insulator by rotating the scatterer.The modulation of the modal coupling by the rotating scatterer enables the beam to have varying width crest and beam energy attenuation rates across a wide band without sidelobes in both near field and far field.By introducing error factors into the structure,it is found that the topological acoustic high performance beamforming device has high fault tolerance,and multiple error factors do not affect the near and far field results of beamforming,which greatly reduces the difficulty of manufacturing and greatly improves the service life of the device.The topological acoustic beamforming and the beamforming under the involvement of error factors are experimentally verified.The experimental results demonstrate the achievement of wide peak beams without sidelobes across a wide band of 4100—4360 Hz and confirm the high fault tolerance of the beamformers when some scatters are missing in the device.This study proposes a new beamforming method that has can provide a reference for the engineering applications of acoustic communication,micro and nano manufacturing,biomedicine,and other micro-shaped and multi-functional acoustic devices and inspires other classical wave fields such as light and electromagnetic waves.