PIEZOELECTRIC THIN-FILM RESONATOR, FILTER, DUPLEXER, COMMUNICATION MODULE, AND COMMUNICATION APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a piezoelectric thin-film resonator in which reduction of an electromechanical coupling coefficient and increase of a standing wave mode are suppressed as compared with a conventional one while preventing energy dissipation of transverse waves.SOLUTION: A piezoelectric thin-film resonator comprises: a substrate 14; an upper electrode 11 and a lower electrode 12 disposed on the substrate 14 in such a manner that portions are opposed to each other; and a piezoelectric film 13 disposed between the upper electrode 11 and the lower electrode 12. The piezoelectric thin-film resonator comprises a mass body 16 disposed on the upper electrode 11. The mass body 16 is disposed on a portion of an edge part of a region opposed to the lower electrode 12 in the upper electrode 11.