Surface acoustic wave device

Abstract

A surface acoustic wave device includes a LiTaO3 substrate, and an IDT having a high reflection coefficient, which has a relatively high electromechanical coupling coefficient k2, and which can obtain superior resonance characteristics and/or filter characteristics. In a surface acoustic wave device in which a plurality of grooves is provided in an upper surface of a LiTaO3 substrate and an IDT having a plurality of electrode fingers made of a metal filled in the plurality of grooves, the following equation is satisfied: (ρ3×C44)1/2>1.95×1011, where ρ represents the density of the metal defining the IDT, and C44 represents the stiffness thereof.

Dependencies are inferred from the claim text.