基于声学超材料的无源声学循环器的设计  

Design of passive acoustic circulator based on acoustic metamaterials

作　　者：朱一凡[1,2] 范旭东[1,2] 梁彬[1,2] 杨京[1,2] 程建春[1,2] Zhu Yifan Fan Xudong Liang Bin Yang Jing Cheng Jianchun(Institute of Acoustics, Nanjing University, Nanj ing, 2100093, China Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China)

机构地区：[1]南京大学声学研究所,南京210093 [2]南京大学微结构与创新协同中心,南京210093

出　　处：《南京大学学报（自然科学版）》2017年第1期76-80,共5页Journal of Nanjing University（Natural Science）

基　　金：国家973计划(2011CB7097900;2012CB921504);国家自然科学基金(11174138;11174139;11222442;81127901)

摘　　要：近年来,新型声学器件的发展迅速,比如声学二极管的提出,类比于传统的电学二极管,实现了对声波的整流和非互易(或非对称)的声传播.随后,声学晶体管也被理论上设计和提出.作为新型的声学概念型设备,声学器件呈现了从简单的二端口向三多口甚至多端口的发展趋势(比如声学二极管到晶体管).另一方面,声学超材料是近10年来的热门研究话题.利用声学超材料的亚波长共振效应,可以实现丰富的功能,包括声学斗篷,声学幻像,聚焦透镜,涡旋场和任意波束形成.将超材料单元引入一个旋转对称的多端口系统,实现了无源的复杂声学网络中的声学路径操控.证明了当超材料提供了打破左右对称的附加波矢后,声学系统中只允许向右(或向左)传播.因此实现了声波只能逆时针传播(或顺时针)的无源声学循环器.解析分析了每个超材料单元对声波的偏转角度来预测声传播路线.最后,进一步将三端口循环器拓展到更多端口的情况.Recently,new type acoustic devices are rising,such as acoustic diodes,in analogy with electronic diode.Acoustic diode can realize rectification of sound with nonreciprocal sound transmission（or asymmetric sound transmission）.Acoustic transistor is also proposed and designed theoretically.As new type of acoustic conceptual devices,there is a tendency shift from simple two-port system to multi-port system（such as diode to transistor）.On the other hand,acoustic metamaterials have received a lot of attentions.By utilizing subwavelength resonance of sound,versatile functionalities can be realized,such as cloaking,illusion,acoustic lens,vortex,and arbitrary beam shaping.In this paper,we introduce the acoustic metamaterials unit cells（AMUC）into a rotational symmetric multi-port system.A passive complex acoustic system is realized with controllable sound path.We demonstrate that the acoustic metamaterial which breaking the symmetry by adding a transverse wave-vector,will make the acoustic system only hold right（or left）transmission,that is,when acoustic wave reach forks in the system,it will always turn right（or left）with the help of the AMUC.Thus,apassive acoustic circulator（PAC）is formed with only anticlockwise sound trans-mission（or clockwise）.We analytically analyze the deflection angles of each AMUC to predict the sound path in the system.The numerical simulations are in good agreement with the theoretically predictions,that the circular sound transmission is observed.At last,we further numerically demonstrate the PAC with more-port cases other than three-port case.This interesting and important feature of PAC will lead to potential applications in many practical occasions,such as noise control,architectural acoustics field,and so forth.

关 键 词：声学超材料 声学循环器 无源 左/右传播 循环传播 

分 类 号：O402[理学—物理]