US6441539B1
Expired / Lapsed
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Piezoelectric resonator
Assignee: Murata Manufacturing Co Ltd
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Filing: 2000-11-06
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Granted: 2002-08-27
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Expires: 2020-11-06
Abstract
Abstract A piezoelectric resonator includes a laminated structure having a piezoelectric laminate, at least one pair of electrodes and a substrate. The piezoelectric laminate includes at least one first piezoelectric layer having a positive temperature coefficient of a resonant frequency and at least one second piezoelectric layer which has a negative temperature coefficient of a resonant frequency. The at least one pair of electrodes interpose at least one of the first and second piezoelectric layers. The substrate supports the laminated structure and holds a portion of the laminated structure such that a suspended portion of the laminated structure vibrates in response to application of a voltage across the pair of electrodes.
Inventors
- 👤 Hidekazu Kitamura
- 👤 Kazuhiro Inoue
- 👤 Masaki Takeuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:42
CPC Classifications
H; H03; H03H; H03H3/00; H03H3/007; H03H3/02; H03H9/00; H03H9/02; H03H9/02007; H03H9/02086; H03H9/02102; H03H9/15; H03H9/17; H03H9/171; H03H9/172; H03H9/173; H03H9/174; H03H9/176
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
88 words
A piezoelectric resonator comprising: a laminated structure including at least one first piezoelectric layer which has a positive temperature coefficient of a resonant frequency and at least one second piezoelectric layer which has a negative temperature coefficient of a resonant frequency; at least a pair of electrodes interposing at least one of the first and second piezoelectric layers; and a substrate supporting the laminated structure and holding a portion of the laminated structure such that the holding portion vibrates by applying a voltage across the pair of electrodes.
Claim 2
Dependent Claim
88 words
A piezoelectric resonator comprising: a laminated structure including at least one first piezoelectric layer which has a positive temperature coefficient of a resonant frequency and at least one second piezoelectric layer which has a negative temperature coefficient of a resonant frequency; at least a pair of electrodes interposing at least one of the first and second piezoelectric layers; and a substrate supporting the laminated structure and holding a portion of the laminated structure such that the holding portion vibrates by applying a voltage across the pair of electrodes.
Claim 3
Dependent Claim
29 words
A piezoelectric resonator according to claim 1 , wherein the pair of electrodes interpose the at least one first piezoelectric layer and the at least one second piezoelectric layer.
Claim 4
Dependent Claim
32 words
A piezoelectric resonator according to claim 1 , wherein the at least one first piezoelectric layer includes as a primary component one of AlN and PbZr x Ti (1−x) O 3 (0.54≦x≦1).
Claim 5
Dependent Claim
45 words
A piezoelectric resonator according to claim 1 , wherein the at least one second piezoelectric layer includes as a primary component one piezoelectric material selected from the group consisting of ZnO, LiNbO 3 , LiTaO 3 , and PbZr x Ti (1−x) O 3 (0≦x≦0.52).
Claim 6
Dependent Claim
47 words
A piezoelectric resonator according to claim 1 , wherein a thickness of the at least one first piezoelectric layer and a thickness of the at least one second piezoelectric layer are such that a temperature coefficient of a resonant frequency of the piezoelectric laminate is substantially zero.
Claim 7
Dependent Claim
31 words
A piezoelectric resonator according to claim 1 , wherein the substrate has a frame shape having an opening, and the holding portion of the laminated structure is positioned above the opening.
Claim 8
Dependent Claim
31 words
A piezoelectric resonator according to claim 1 , wherein the laminated structure has an air-bridge structure in which the holding portion of the laminated structure is spaced apart from the substrate.
Claim 9
Dependent Claim
44 words
A piezoelectric resonator according to claim 1 , wherein the piezoelectric laminate includes an additional first piezoelectric layer, the additional first piezoelectric layer and the at least one first piezoelectric layer have substantially the same thickness and interpose the at least second piezoelectric layer.
Claim 10
Dependent Claim
44 words
A piezoelectric resonator according to claim 1 , wherein the piezoelectric laminate includes an additional second piezoelectric layer, the additional second piezoelectric layer and the at least one second piezoelectric layer have substantially the same thickness and interpose the at least first piezoelectric layer.
Claim 11
Dependent Claim
23 words
A piezoelectric resonator according to claim 1 , wherein the laminated structure includes an insulating layer between the substrate and the piezoelectric laminate.
Claim 12
Dependent Claim
29 words
A piezoelectric resonator according to claim 10 , wherein the pair of electrodes interpose the at least one first piezoelectric layer and the at least one second piezoelectric layer.
Claim 13
Dependent Claim
32 words
A piezoelectric resonator according to claim 10 , wherein the at least one first piezoelectric layer includes as a primary component one of AlN and PbZr x Ti (1−x) O 3 (0.54≦x≦1).
Claim 14
Dependent Claim
45 words
A piezoelectric resonator according to claim 10 , wherein the at least one second piezoelectric layer includes as a primary component, one piezoelectric material selected from the group consisting of ZnO, LiNbO 3 , LiTaO 3 , and PbZr x Ti (1−x) O 3 (0≦x≦0.52).
Claim 15
Dependent Claim
53 words
A piezoelectric resonator according to claim 10 , wherein a thickness of the at least one first piezoelectric layer, a thickness of the at least one second piezoelectric layer and a thickness of the insulating layer are such that a temperature coefficient of a resonant frequency of the piezoelectric laminate is substantially zero.
Claim 16
Dependent Claim
31 words
A piezoelectric resonator according to claim 10 , wherein the substrate has a frame shape having an opening, and the holding portion of the laminated structure is positioned above the opening.
Claim 17
Dependent Claim
31 words
A piezoelectric resonator according to claim 10 , wherein the laminated structure has an air-bridge structure in which the holding portion of the laminated structure is spaced apart from the substrate.
Claim 18
Dependent Claim
140 words
A filter comprising: an input terminal; an output terminal; first and second piezoelectric resonators each including: a laminated structure including at least one first piezoelectric layer which has a positive temperature coefficient of a resonant frequency and at least one second piezoelectric layer which has a negative temperature coefficient of a resonant frequency; at least a pair of electrodes interposing at least one of the first and second piezoelectric layers; and a substrate supporting the laminated structure and holding a portion of the laminated structure such that the holding portion vibrates by applying a voltage across the pair of electrodes; wherein the first piezoelectric resonator is connected between the input terminal and the output terminal to define a series arm and the second piezoelectric resonator is connected between the series arm and a ground level to define a series arm.
Claim 19
Dependent Claim
140 words
A filter comprising: an input terminal; an output terminal; first and second piezoelectric resonators each including: a laminated structure including at least one first piezoelectric layer which has a positive temperature coefficient of a resonant frequency and at least one second piezoelectric layer which has a negative temperature coefficient of a resonant frequency; at least a pair of electrodes interposing at least one of the first and second piezoelectric layers; and a substrate supporting the laminated structure and holding a portion of the laminated structure such that the holding portion vibrates by applying a voltage across the pair of electrodes; wherein the first piezoelectric resonator is connected between the input terminal and the output terminal to define a series arm and the second piezoelectric resonator is connected between the series arm and a ground level to define a series arm.
Claim 20
Dependent Claim
26 words
A filter according to claim 17 , wherein the filter is one of a T-type ladder filter, an L-type ladder filter and a π-type ladder filter.
Claim 21
Dependent Claim
14 words
An electronic apparatus comprising at least one piezoelectric resonator according to claim 1 .
Claim 22
Dependent Claim
29 words
An electronic apparatus according to claim 17 , wherein the apparatus includes at least one of a T-type ladder filter, an L-type ladder filter and a π-type ladder filter.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-08-26 | 2006-02-25 | 2006-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-08-26 | 2010-02-25 | 2010-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-08-26 | 2014-02-25 | 2014-08-27 | $7700.00 | Window Closed / Lapsed |