Directional enhanced acoustic radiation caused by a point cavity in a finite-size two-dimensional phononic crystal

Abstract

In this letter, we present results of a study on the directional enhanced radiation generated by a point resonant cavity operating at the band-gap frequency of a two-dimensional finite-size phononic crystal. We find that the directive radiation for operating frequency within the band gap comes from the direction-dependent transmittance property of the square-lattice phononic crystal. The directive-radiation characteristic can be capitalized on enhancing the emission from the phononic crystals by coupling the source with point-defect modes, and the enhanced directive radiation patterns with main lobe width less than 12.9° are demonstrated.

Focusing and directional beaming effects of airborne sound through a planar lens with zigzag slits

“…The former is frequently accompanied with the excitation of specific states in the crystals, e.g. the cavity states [30][31][32] and band-edge states [33], whereas the latter is often connected with the resonant excitation of the structure-induced surface acoustic waves [35][36][37]. Different three-dimension version of the planar lens can be directly designed with using zigzag hole-arrays.…”

Band Structures Analysis Method of Two-Dimensional Phononic Crystals Using Wavelet-Based Elements

“…[4]. The mechanism for tuning PC band-gap also possesses significant practical applications in the design of vibrationless environments for high-precision mechanical systems [5]. However, the calculation results had a great influence on the studies of PC band-gap mechanism and wave propagation characteristic.…”

Bandgap analysis of two-dimensional phononic crystals

“…The finite difference time domain method [10] and the finite element method [11] have good convergence in the calculations of phononic crystals, but their formed matrix is large and time-consuming. The multiple-scattering theory method [12] has a larger multipole expansion, and it can only treat the cylindrical or spherical inclusions. The wavelet method [13] need adopt suitable basis functions and consume more time.…”