BULK ACOUSTIC WAVE DEVICE WITH RECESSED FRAME STRUCTURE IN ACOUSTICALLY ACTIVE REGION

Original (Chinese)

Aspects of this disclosure relate to a bulk acoustic wave resonator having an acoustically active region and a peripheral region. The bulk acoustic wave resonator can include a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a recessed frame structure at least partially in the acoustically active region. The piezoelectric layer can have an effective piezoelectric coefficient with a lower magnitude in the peripheral region than in the acoustically active region. Other embodiments of bulk acoustic wave resonators are disclosed. Related filters, multiplexers, radio frequency modules, radio frequency systems, wireless communication devices, and methods are disclosed.