Patent ID: 7939988
Filing Date: 2011-05-10
Classification: H03H

Abstract:
1. An acoustic wave device comprising: a piezoelectric substrate made of lithium niobate and having a surface adapted to allow a leaky surface wave to propagate thereon; an interdigital electrode made of aluminum and provided on a portion of the surface of the piezoelectric substrate; and a dielectric layer made of tantalum pentoxide provided on the surface of the piezoelectric substrate to cover the interdigital electrode, wherein the piezoelectric substrate is made of a rotated Y-cut substrate having a cut angle which is not smaller than 2.5 degrees and is not larger than 22.5 degrees, and a ratio H/λ of a film thickness H of the dielectric layer to a wavelength λ of a center frequency of the leaky surface wave ranges from 0.034 to 0.126.