Broadband directional acoustic waveguide with high efficiency

We have realized both theoretically and experimentally a directional acoustic transmission in a bended waveguide. For acoustic plane waves that incident from the two openings of the waveguide, an efficient partial band gap of dispersion relations is yielded by employing a linear two-dimensional phononic crystal properly designed according to the structural parameters of waveguide. As a result, a highly efficient directional transmission of acoustic waves can be achieved within a broad frequency range. The numerical predictions agree well with the experimental results. This should be potentially significant in various areas such as medical ultrasound and duct acoustics. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4739081]