Resonant Inc.
SOLIDLY-MOUNTED TRANSVERSELY-EXCITED FILM BULK ACOUSTIC RESONATOR WITH RECESSED INTERDIGITAL TRANSDUCER FINGERS USING ROTATED Y-X CUT LITHIUM NIOBATE

Abstract:

Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate, a lithium niobate plate having front and back surfaces, wherein Euler angles of the lithium niobate plate are [0.degree., .beta., 0.degree.], where l is greater than or equal to 0.degree. and less than or equal to 60.degree., and an acoustic Bragg reflector between the surface of the substrate and the back surface of the lithium niobate plate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate. At least one finger of the IDT is disposed in a groove in the lithium niobate plate.