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Patent US5283458A successfully refreshed from Google Patents.
US5283458A
Expired / Lapsed
US
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Temperature stable semiconductor bulk acoustic resonator
Assignee: Northrop Grumman Systems Corp
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Filing: 1992-03-30
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Granted: 1994-02-01
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Expires: 2012-03-30
Abstract
Abstract This invention discloses a semiconductor bulk acoustic resonator including at least one thin film piezoelectric layer positioned on a semiconductor substrate. The acoustic resonator includes a heating ring positioned around the outer perimeter of the piezoelectric layer in order to heat the piezoelectric layer to a desirable elevated temperature. A heat sensing film fabricated on the piezoelectric layer monitors the temperature of the piezoelectric layer such that the heating ring maintains the piezoelectric layer at a constant temperature. By this, an oscillator circuit using this semiconductor bulk acoustic resonator as the frequency controlling element can maintain a constant frequency over a wide range of temperatures which may affect frequency stability.
Inventors
- 👤 Robert B. Stokes
- 👤 Kei-Fung Lau
- 👤 James Chung-Kei Lau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:36
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/15; H03H9/17; H03H9/171; H03H9/172
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
72 words
A semiconductor bulk acoustic resonating device comprising: a semiconductor substrate; a piezoelectric device positioned on the substrate, said piezoelectric device including at least one electrode operable to receive an electrical signal such that when the electrode receives the electrical signal, the piezoelectric device converts the electrical energy into acoustical energy; and a heating device, said heating device being positioned adjacent to the piezoelectric device and being operable to heat the piezoelectric device.
Claim 2
Dependent Claim
72 words
A semiconductor bulk acoustic resonating device comprising: a semiconductor substrate; a piezoelectric device positioned on the substrate, said piezoelectric device including at least one electrode operable to receive an electrical signal such that when the electrode receives the electrical signal, the piezoelectric device converts the electrical energy into acoustical energy; and a heating device, said heating device being positioned adjacent to the piezoelectric device and being operable to heat the piezoelectric device.
Claim 3
Dependent Claim
47 words
The acoustic resonating device according to claim 1 further comprising a heat sensing device, said heat sensing device positioned relative to the piezoelectric device and being operable to sense the temperature of the piezoelectric device and generate a signal indicative of the temperature of the piezoelectric device.
Claim 4
Dependent Claim
19 words
The acoustic resonating device according to claim 2 wherein the heat sensing device is a film of vanadium dioxide.
Claim 5
Dependent Claim
24 words
The acoustic resonating device according to claim 1 wherein the heating device is a heating ring positioned around the perimeter of the piezoelectric device.
Claim 6
Dependent Claim
29 words
The acoustic resonating device according to claim 1 wherein the substrate includes a recess and wherein the piezoelectric device is positioned relative to and in contact with the recess.
Claim 7
Dependent Claim
48 words
The acoustic resonating device according to claim 1 wherein the piezoelectric device is comprised of a first electrode layer, a second electrode layer and a piezoelectric layer positioned between the first and second electrode layers, the first and second electrode layers being operable to receive the electrical signal.
Claim 8
Dependent Claim
48 words
The acoustic resonating device according to claim wherein the heating device is a heating ring positioned around the perimeter of the piezoelectric device, and wherein the acoustic resonator further comprises a heat sensing film positioned within an inner circumference of the heating ring proximate to the piezoelectric device.
Claim 9
Dependent Claim
36 words
The acoustic resonating device according to claim 1 wherein the piezoelectric device is comprised of an alternating configuration of electrode layers and piezoelectric layers including at least three electrode layers and at least two piezoelectric layers.
Claim 10
Dependent Claim
131 words
A semiconductor bulk acoustic resonator comprising: a semiconductor substrate; a piezoelectric device positioned on the substrate, said piezoelectric device including at least one electrode operable to receive an electrical signal, wherein when the electrode receives the electrical signal, the piezoelectric device converts the electrical energy into acoustical energy at a predetermined frequency; a heating ring positioned around a perimeter of and in contact with the piezoelectric device, said heating ring operable to receive an electrical signal for heating the piezoelectric device to a substantially constant elevated temperature; and a heat sensing film positioned within an inner circumference of the heating ring proximate to the piezoelectric device, said heat sensing film operable to monitor the temperature of the piezoelectric device and provide a signal indicative of the temperature of the piezoelectric device.
Claim 11
Dependent Claim
131 words
A semiconductor bulk acoustic resonator comprising: a semiconductor substrate; a piezoelectric device positioned on the substrate, said piezoelectric device including at least one electrode operable to receive an electrical signal, wherein when the electrode receives the electrical signal, the piezoelectric device converts the electrical energy into acoustical energy at a predetermined frequency; a heating ring positioned around a perimeter of and in contact with the piezoelectric device, said heating ring operable to receive an electrical signal for heating the piezoelectric device to a substantially constant elevated temperature; and a heat sensing film positioned within an inner circumference of the heating ring proximate to the piezoelectric device, said heat sensing film operable to monitor the temperature of the piezoelectric device and provide a signal indicative of the temperature of the piezoelectric device.
Claim 12
Dependent Claim
22 words
The acoustic resonator of claim 9 wherein the substrate includes a recess wherein the piezoelectric device is positioned relative to the recess.
Claim 13
Dependent Claim
14 words
The acoustic resonator of claim 9 wherein the heat sensing film is vanadium dioxide.
Claim 14
Dependent Claim
42 words
The acoustic resonator of claim 9 wherein the piezoelectric device includes a piezoelectric layer positioned between a first electrode layer and a second electrode layer, the first and second electrode layers operable to receive the electrical signals for driving the piezoelectric layer.
Claim 15
Dependent Claim
30 words
The acoustic resonator of claim 9 wherein the piezoelectric device includes an alternating configuration of piezoelectric layers and electrode layers having at least two piezoelectric layers and three electrode layers.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-31 | 1997-08-02 | 1998-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-31 | 2001-08-02 | 2002-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-31 | 2005-08-02 | 2006-02-01 | $7700.00 | Window Closed / Lapsed |