Esfahlani Hussein, Karkar Sami, Lissek Hervé, Mosig Juan R
Laboratoire de Traitement des Signaux LTS2, Ecole Polytechnique Fédérale de Lausanne, Station 11, CH-1015, Lausanne, Switzerland.
Laboratoire d'Electromagnétisme et d'Antennes LEMA, Ecole Polytechnique Fédérale de Lausanne, Station 11, CH-1015, Lausanne, Switzerland.
J Acoust Soc Am. 2016 Jun;139(6):3259. doi: 10.1121/1.4949544.
A transmission-line acoustic metamaterial is an engineered, periodic arrangement of relatively small unit-cells, the acoustic properties of which can be manipulated to achieve anomalous physical behaviours. These exotic properties open the door to practical applications, such as an acoustic leaky-wave antenna, through the implementation of radiating channels along the metamaterial. In the transmitting mode, such a leaky-wave antenna is capable of steering sound waves in frequency-dependent directions. Used in reverse, the antenna presents a well defined direction-frequency behaviour. In this paper, an acoustic leaky-wave structure is presented in the receiving mode. It is shown that it behaves as a sound source direction-finding device using only one sensor. After a general introduction of the acoustic leaky-wave antenna concept, its radiation pattern and radiation efficiency are expressed in closed form. Then, numerical simulations and experimental assessments of the proposed transmission-line based structure, implementing only one sensor at one termination, are presented. It is shown that such a structure is capable of finding the direction of an incoming sound wave, from backward to forward, based on received sound power spectra. This introduces the concept of sound source localization without resorting to beam-steering techniques based on multiple sensors.
传输线声学超材料是一种由相对较小的单元胞组成的经过设计的周期性排列结构，其声学特性可被操控以实现异常的物理行为。这些奇特的特性为诸如声学漏波天线等实际应用打开了大门，通过在超材料中沿其实施辐射通道来实现。在发射模式下，这种漏波天线能够在与频率相关的方向上操控声波。反过来使用时，该天线呈现出明确的方向 - 频率特性。在本文中，提出了一种处于接收模式的声学漏波结构。结果表明，它仅使用一个传感器就能作为一种声源测向装置。在对声学漏波天线概念进行一般性介绍之后，其辐射方向图和辐射效率以封闭形式表示。然后，给出了所提出的基于传输线结构的数值模拟和实验评估，该结构仅在一端放置一个传感器。结果表明，这种结构能够基于接收到的声功率谱从后向前找到入射声波的方向。这引入了一种无需借助基于多个传感器的波束控制技术的声源定位概念。
