PIEZOELECTRIC THIN FILM RESONATOR AND FILTER

摘要

PROBLEM TO BE SOLVED: To suppress a spurious emission.SOLUTION: A piezoelectric thin film resonator comprises: a substrate; a piezoelectric film disposed on the substrate; a lower electrode and an upper electrode disposed with the piezoelectric film in between; and a load film 28 formed of a plurality of patterns 52 within a resonance region 50, where the lower electrode and the upper electrode are opposite with the piezoelectric film in between. The plurality of patterns 52 are formed so as to be intersected by a path 64 from a center 60 to a periphery 62 of the resonance region 50 and to surround the center.