Frequency separation of surface acoustic waves in layered structures with acoustic metamaterials

• Mathematical model of Love wave propagation in inhomogeneous waveguide is developed.
• Love wave in inhomogeneous waveguide can be spatially separated.
• Parameters of elastic metamaterial reveal resonant properties.
• Elastic metamaterial can be used to enhance spatial separation of SAW.

We show theoretically that in elastic layered structures containing an upper layer of smoothly varied thickness and a substrate of a highly dispersive metametarial it is possible to significantly enhance spatial frequency separation of surface acoustic waves. Theory of Love surface acoustic waves propagation in waveguides with varied thickness, taking into account mutual modes coupling, is built. Appropriate structure of metamatererial with resonant frequency dependence of material parameters, making frequency separation effective, is provided. Efficiency of spatial frequency separation and modes coupling is calculated for various metamaterial parameters and wave frequencies.