Resonant Inc.
TRANSVERSELY-EXCITED FILM BULK ACOUSTIC RESONATOR USING YX-CUT LITHIUM NIOBATE FOR HIGH POWER APPLICATIONS

Abstract:

Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate and a lithium niobate (LN) plate having front and back surfaces and a thickness ts. The back surface is attached to a surface of the substrate. A portion of the LN plate forms a diaphragm spanning a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the LN plate with interleaved fingers of the IDT disposed on the diaphragm. The LN plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic wave in the diaphragm. Euler angles of the LN plate are [0.degree., .beta., 0.degree. ], where 0.ltoreq..beta..ltoreq.60.degree.. A thickness of the interleaved fingers of the IDT is greater than or equal to 0.8 ts and less than or equal to 2.0 ts.