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US 12,224,732 B2Granted
Solidly-mounted transversely-excited film bulk acoustic resonators and filters for 27 GHz communications bands
AssigneeMurata Manufacturing Co., Ltd.
InventorsGregory L. Hey-Shipton, Neal Fenzi, Mike Eddy, Ventsislav Yantchev
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Abstract
Resonator devices and filter devices are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate having front and back surfaces separated by a piezoelectric plate thickness greater than or equal to 50 nm and less than or equal to 200 nm. An acoustic Bragg reflector is between the substrate and the back surface of the piezoelectric plate. A conductor pattern including an interdigital transducer (IDT) is on the front surface of the piezoelectric plate.
Claims18
An acoustic resonator comprising:
- a substrate;
- a piezoelectric plate having front and back surfaces and having a piezoelectric plate thickness between the front and back surfaces that is greater than or equal to 50 nm and less than or equal to 200 nm;
- an acoustic Bragg reflector between the substrate and the back surface of the piezoelectric plate;
- and
- a conductor pattern comprising an interdigital transducer (IDT) on the front surface of the piezoelectric plate,
- wherein the IDT comprises interleaved fingers on the piezoelectric plate and at least a portion of the interleaved fingers have a width that is greater than or equal to 0.2 times a pitch of the IDT and less than or equal to 0.3 times the pitch of the IDT.
3 more elements
A filter device comprising:
- a plurality of bulk acoustic resonators connected in a ladder filter circuit, each bulk acoustic resonator of the plurality of bulk acoustic resonators comprising:
- a substrate;
- a piezoelectric plate having front and back surfaces and a piezoelectric plate thickness between the front and back surfaces that is greater than or equal to 50 nm and less than or equal to 200 nm;
- an acoustic Bragg reflector between the substrate and the back surface of the piezoelectric plate;
- and
- a conductor pattern on the front surface of the piezoelectric plate, the conductor pattern comprising an interdigital transducer (IDT),
- wherein the plurality of bulk acoustic resonators comprises at least a first shunt resonator and at least a first series resonator, and
- wherein a thickness of a first dielectric layer over the IDT of the first shunt resonator is greater than a thickness of a second dielectric layer over the IDT of the first series resonator.
5 more elements
A filter device comprising:
- a plurality of bulk acoustic resonators connected in a ladder filter circuit, each bulk acoustic resonator of the plurality of bulk acoustic resonators comprising:
- a substrate;
- a piezoelectric plate having front and back surfaces and a piezoelectric plate thickness between the front and back surfaces that is greater than or equal to 50 nm and less than or equal to 200 nm;
- an acoustic Bragg reflector between the surface of the substrate and the back surface of the piezoelectric plate;
- and
- a conductor pattern on the front surface of the piezoelectric plate, the conductor pattern comprising an interdigital transducer (IDT),
- wherein the IDT of each bulk acoustic resonator comprises interleaved fingers on the piezoelectric plate and at least a portion of the interleaved fingers have a width that is greater than or equal to 0.2 times a pitch of the IDT and less than or equal to 0.3 times the pitch of the IDT.
4 more elements
Dependencies are inferred from the claim text.