Surface acoustic wave device

摘要

A surface acoustic wave device includes a piezoelectric substrate (2), and an interdigital transducer (3) provided on the piezoelectric substrate (2), wherein the piezoelectric substrate (2) includes at least two piezoelectric ceramic layers made of a polycrystalline material. The at least two piezoelectric ceramic layers are stacked so that electrical characteristics and mechanical characteristics thereof vary in a direction that is substantially perpendicular to a surface of the piezoelectric substrate (2) upon which the at least two ceramic piezoelectric layers are stacked.