Bragg reflection of Bleustein-Gulyaev(BG) waves in a magneto-electro-elastic substrate with a periodically inertial load surface

Abstract

Based on the Bloch's theorem and the coupling of modes approximation, an explicit dispersion equation and frequency responses of Bleustein-Gulyaev (BG) wave near its Bragg resonance frequency in a magneto-electro-elastic (MEE) substrate with a periodically inertial load surface are obtained. The complex band structure is calculated with the imaginary part of Bloch wave vector quantifying wave attenuation. The effects of inertial load perturbations and constituent ratios of MEE substrate on the complex band structures are discussed. Our results show that BG waves decay the fastest at the center frequency of the band gap. The width and the location of the band gap can be tuned, respectively, by the periodically changing load and the uniformly inertial load. This work provides a simple way to tune the band gap of surface acoustic wave (SAW), which should be helpful for the relevant applications in MEE SAW devices such as Bragg reflectors and resonators.