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US 12,445,112 B2Granted
Acoustic wave filter and multiplexer
AssigneeMurata Manufacturing Co., Ltd.
InventorTomohisa Komura
Life of this patent
Estimating the term…
Abstract
An acoustic wave filter includes at least one of a first series arm resonator circuit in a path connecting input/output terminals and a first parallel arm resonator circuit between a node in the path and ground. At least one of the first series arm resonator circuit and the first parallel arm resonator circuit includes a segmented resonator group including first and second acoustic wave resonators connected in series, an IDT electrode included in the first acoustic wave resonator includes a first withdrawal electrode, and C1/r1>C2/r2 and r1<r2 are satisfied.
Claims18
An acoustic wave filter comprising:
- a first input/output terminal and a second input/output terminal;
- and
- at least one series arm resonator circuit in a path connecting the first input/output terminal and the second input/output terminal or at least one parallel arm resonator circuit each between a node in the path and ground or both of the at least one series arm resonator circuit and the at least one parallel arm resonator circuit;
- wherein
- each of the at least one series arm resonator circuit or each of the at least one parallel arm resonator circuit or each of both of the at least one series arm resonator circuit and the at least one parallel arm resonator circuit includes an acoustic wave resonator including an IDT (InterDigital Transducer) electrode on a substrate having piezoelectricity,
- at least one of a first series arm resonator circuit included in the at least one series arm resonator circuit and a first parallel arm resonator circuit included in the at least one parallel arm resonator circuit, includes a segmented resonator group including a first acoustic wave resonator and a second acoustic wave resonator, the first acoustic wave resonator and the second acoustic wave resonator being connected in series to one another;
- the IDT electrode included in the first acoustic wave resonator includes a first withdrawal electrode;
- the IDT electrode included in the second acoustic wave resonator includes a second withdrawal electrode;
- and
- C1/r1>C2/r2 and r1<r2 are satisfied where C1 is a capacitance of the IDT electrode included in the first acoustic wave resonator, C2 is a capacitance of the IDT electrode included in the second acoustic wave resonator, r1 is a withdrawal ratio of the IDT electrode included in the first acoustic wave resonator, and r2 is a withdrawal ratio of the IDT electrode included in the second acoustic wave resonator.
7 more elements
An acoustic wave filter comprising:
- a first input/output terminal and a second input/output terminal;
- and
- at least one series arm resonator circuit in a path connecting the first input/output terminal and the second input/output terminal or at least one parallel arm resonator circuit each between a node in the path and ground or both of the at least one series arm resonator circuit and the at least one parallel arm resonator circuit;
- wherein
- each of the at least one series arm resonator circuit or each of the at least one parallel arm resonator circuit or each of both of the at least one series arm resonator circuit and the at least one parallel arm resonator circuit includes an acoustic wave resonator including an IDT electrode on a substrate having piezoelectricity;
- one of a first series arm resonator circuit included in the at least one series arm resonator circuit or a first parallel arm resonator circuit included in the at least one parallel arm resonator circuit or both of the first series arm resonator circuit and the first parallel arm resonator circuit, each include a segmented resonator group including a first acoustic wave resonator and a second acoustic wave resonator, the first acoustic wave resonator and the second acoustic wave resonator being connected in series to one another;
- the IDT electrode included in the first acoustic wave resonator includes a first withdrawal electrode;
- the IDT electrode included in the second acoustic wave resonator includes a second withdrawal electrode;
- and
- a product of a number of electrode fingers, an intersecting width, an electrode duty, and an electrode film thickness of the IDT electrode included in the first acoustic wave resonator is larger than a product of a number of electrode fingers, an intersecting width, an electrode duty, and an electrode film thickness of the IDT electrode included in the second acoustic wave resonator, and a withdrawal ratio of the IDT electrode included in the first acoustic wave resonator is smaller than a withdrawal ratio of the IDT electrode included in the second acoustic wave resonator.
7 more elements
Dependencies are inferred from the claim text.