Surface acoustic wave filter and communications apparatus using the same

摘要

A surface acoustic wave includes a surface acoustic wave element including a piezoelectric substrate having IDTs, input/output terminals, and reference potential terminals provided thereon and a package enclosing the surface acoustic element and having electrode lands and external terminals. The resonance frequency of the resonator defined by inductances generated by the reference potential terminals of the external terminals of the package, is positioned in the vicinity of an image frequency occurring at a time of performing frequency conversion in a super heterodyne system.