Resonant Inc.
SOLIDLY-MOUNTED TRANSVERSELY-EXCITED FILM BULK ACOUSTIC FILTERS WITH EXCESS PIEZOELECTRIC MATERIAL REMOVED

Abstract:

Filters and methods of making filters are disclosed. A filter device includes a substrate, a piezoelectric plate, and an acoustic Bragg reflector between a surface of the substrate and a back surface of the piezoelectric plate. A conductor pattern on a front surface of the piezoelectric plate includes interdigital transducers (IDTs) of a plurality of resonators and a plurality of conductors to connect the plurality of resonators in a ladder filter circuit, the plurality of conductors including adjacent first and second conductors. A portion of the piezoelectric plate between the first and second conductors is removed.