Design of acoustic beam aperture modifier using gradient-index phononic crystals

This paper reports the design of a novel acoustic beam aperture modifier using gradient-index phononic crystals consisting of different solid cylinders embedded in a homogeneous epoxy background. Dispersion curves of the acoustic waves were calculated using a plane-wave expansion (PWE) method and their propagation in the proposed structure was simulated by a finite-element time-domain (FDTD) method. Computational experiments elucidate the effectiveness of the acoustic beam aperture modifier.