A three-dimensional broadband underwater acoustic concentrator

Abstract

Abstract We propose a three-dimensional (3D) omnidirectional underwater acoustic concentrator based on the concept of acoustic prison, which can realize a substantial enhancement of underwater sound signals in broadband ranges. This device mainly employs the non-resonant multiple reflection characteristics of the semi-enclosed geometric space, so it has a wide working frequency bandwidth. Compared with the previous reported concentrators based on transform acoustics mechanism, the structure is more simple, and most importantly, it can realize omnidirectional signal enhancement in 3D space. Moreover, the working frequency band of this acoustic concentrator depends on the size of the concentrator, so it can be changed directly through a size scaling, which is convenient for engineering applications. In general, the designed underwater acoustic concentrator has the advantages of simple structure, scalability and large bandwidth of working frequency, and high signal gain. It has potential application values in underwater target detection and other aspects.