Abstract
Acoustic waves in a phononic crystal (PnC) showed properties of band gaps and anisotropic propagation and promised many applications. By arranging the filling fraction of PnCs gradually in space, a gradient-index (GRIN) PnC was proposed to bend the wave propagation. GRIN PnCs were reported and applied as an acoustic lens to focus acoustic waves. Theoretically, this kind of lens has a hyperbolic secant refractive index profile along the transverse direction. In this paper, a two-dimensional GRIN PnC for surface acoustic wave (SAW) was studied. The anisotropy of SAW in PnCs was analyzed and trajectories of a SAW beam were estimated. A 16-layers GRIN tungsten/silicon PnC lens was designed. FEM simulation showed that a 150-MHz SAW beam was focused in the GRIN PnC. The GRIN PnC could be applied as a beam aperture modifier or a beamwidth compressor.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
