King Abdullah University of Science and Technology (KAUST), Division of Computer, Electrical and Mathematical Sciences and Engineering, Thuwal, 23955-6900, Saudi Arabia.
GOWell International LLC, Houston, Texas, 77041, USA.
Sci Rep. 2018 Jan 18;8(1):1018. doi: 10.1038/s41598-017-16792-6.
We propose to achieve efficient emission of highly directional sound beams from multiple monopole sources embedded in a subwavelength enclosure. Without the enclosure, the emitted sound fields have an indistinguishable or omnidirectional radiation directivity in far fields. The strong directivity formed in the presence of the enclosure is attributed to interference of sources under degenerate Mie resonances in the enclosure of anisotropic property. Our numerical simulations of sound emission from the sources demonstrate the radiation of a highly directed sound beam of unidirectional or bidirectional patterns, depending on how the sources are configured inside the enclosure. Our scheme, if achieved, can solve the challenging problem of poor directivity of a subwavelength sound system, and can guide beam forming and collimation by miniaturized devices.
我们提出了一种方法，通过在亚波长封闭空间中嵌入多个单极子声源，实现高效发射具有高度指向性的声束。没有封闭空间时，远场中发射的声场具有不可区分或全向的辐射指向性。封闭空间中形成的强指向性归因于各向异性封闭空间中简并米氏共振下的源干涉。我们对声源声辐射的数值模拟表明，根据声源在封闭空间内的配置方式，可辐射具有单向或双向模式的高度定向声束。如果这一方案得以实现，它可以解决亚波长声系统指向性差的难题，并可通过小型化器件来指导波束形成和准直。
