Experimental and numerical investigations of mechanical displacements in surface acoustic wave bounded beams

R Weser; A N Darinskii; M Weihnacht; H Schmidt

doi:10.1016/j.ultras.2020.106077

Experimental and numerical investigations of mechanical displacements in surface acoustic wave bounded beams

Ultrasonics. 2020 Aug:106:106077. doi: 10.1016/j.ultras.2020.106077. Epub 2020 Jan 29.

Authors

R Weser¹, A N Darinskii², M Weihnacht³, H Schmidt⁴

Affiliations

¹ Leibniz Institute for Solid State and Materials Research Dresden, SAWLab Saxony, Helmholtzstr. 20, 01069 Dresden, Germany. Electronic address: r.weser@ifw-dresden.de.
² Shubnikov Institute of Crystallography FSRC "Crystallography and Photonics", Russian Academy of Sciences, Leninskii pr. 59, Moscow 119333, Russia.
³ InnoXacs, Am Muehlfeld 34, 01744 Dippoldiswalde, Germany.
⁴ Leibniz Institute for Solid State and Materials Research Dresden, SAWLab Saxony, Helmholtzstr. 20, 01069 Dresden, Germany.

PMID: 32305680
DOI: 10.1016/j.ultras.2020.106077

Abstract

The present paper studies experimentally and numerically the surface acoustic wave (SAW) field on a piezoelectric substrate generated by interdigital transducers (IDT). On the one hand, mechanical displacements produced by the SAW are measured with the help of a laser Doppler vibrometer. On the other hand, mechanical displacements are computed by the two-dimensional finite element method in frequency domain followed by the spatial Fourier transform. Combining these two steps of computations results in the intended two-dimensional distribution of mechanical displacements on the substrate surface. The comparison of experimental and numerical data obtained for a series of different IDTs reveals that it is possible to estimate the shape of the SAW beam and the absolute value of mechanical displacement amplitude using only the basic parameters of the IDT and its electrical admittance measured by a network analyzer.

Keywords: Finite element method; Interdigital transducer; Laser Doppler vibrometer; Mechanical displacement amplitude; Piezoelectric substrate; Surface acoustic wave.