US 12,451,864 B2
Transversely-excited film bulk acoustic resonators with curved shaped ends of fingers or opposing busbars
Greg Dyer, Santa Barbara, CA (US)
Assigned to Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Sep. 29, 2022, as Appl. No. 17/956,132.
Claims priority of provisional application 63/249,575, filed on Sep. 29, 2021.
Prior Publication US 2023/0111410 A1, Apr. 13, 2023
Int. Cl. H03H 9/205 (2006.01); H03H 9/02 (2006.01); H03H 9/56 (2006.01)
CPC H03H 9/205 (2013.01) [H03H 9/02015 (2013.01); H03H 9/02228 (2013.01); H03H 9/568 (2013.01)] 20 Claims
OG exemplary drawing
 
12. An acoustic resonator device comprising:
a substrate having a surface;
a piezoelectric plate having front and back surfaces, the back surface attached to the surface of the substrate, except for a portion of the piezoelectric plate forming a diaphragm that is over a cavity; and
a conductor pattern including an interdigital transducer (IDT) on the front surface of the piezoelectric plate, such that interleaved fingers of the IDT are on the diaphragm,
wherein the IDT includes a first set of the interleaved fingers attached to and extending from a first busbar, and a second set of the interleaved fingers attached to and extending from a second busbar,
wherein gaps between ends of the set of first interleaved fingers and the second busbar have one of circular gap shapes or parabolic gap shapes,
gaps between ends of the set of second interleaved fingers and the first busbar have one of circular gap shapes or parabolic gap shapes, and
wherein an inner surface of the first busbar has a curved shaped.