US5365138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double mode surface wave resonators
Assignee: Apple Inc
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Filing: 1993-12-02
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Granted: 1994-11-15
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Expires: 2013-12-02
Abstract
Abstract A double mode surface wave resonator comprises two IDTs (inter-digital transducers), arranged side by side between reflection gratings, on a surface of a piezoelectric substrate to provide for coupling of surface waves therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT. One or each of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator. The electrodes of the IDTs can be arranged in spatial synchronism with adjacent fingers of the reflection gratings to reduce spurious longitudinal modes.
Inventors
- 👤 John C. B. Saw
- 👤 Thomas P. Cameron
- 👤 Mark S. Suthers
- 👤 John J. Nisbet
- 👤 Samuel A. Tiller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:42
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/64; H03H9/6423; H03H9/6433; H03H9/644; H03H9/6456; H03H9/6459; H03H9/6463; H03H9/0023; H03H9/0028; H03H9/0047; H03H9/0052; H03H9/0057; H03H9/25
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
87 words
A surface wave resonator comprising: a piezoelectric substrate; and two IDTs (inter-digital transducers) arranged side by side on a surface of the substrate with a common rail therebetween, so that surface waves are coupled between the IDTs, each IDT having interleaved electrodes extending from the common rail and from a respective outer rail, the outer rails providing signal connections to the resonator; wherein at least one of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator.
Claim 2
Dependent Claim
87 words
A surface wave resonator comprising: a piezoelectric substrate; and two IDTs (inter-digital transducers) arranged side by side on a surface of the substrate with a common rail therebetween, so that surface waves are coupled between the IDTs, each IDT having interleaved electrodes extending from the common rail and from a respective outer rail, the outer rails providing signal connections to the resonator; wherein at least one of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator.
Claim 3
Dependent Claim
32 words
A surface wave resonator as claimed in claim 1 wherein each of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator.
Claim 4
Dependent Claim
18 words
A surface wave resonator as claimed in claim 2 wherein the common rail is divided into two halves.
Claim 5
Dependent Claim
53 words
A surface wave resonator as claimed in claim 1 wherein only one of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator, and the outer rail of the other IDT and the common rail provide an unbalanced signal connection to the resonator.
Claim 6
Dependent Claim
28 words
A surface wave resonator as claimed in claim 1 and including reflection gratings between which the two IDTs are arranged to define a resonant cavity for each IDT.
Claim 7
Dependent Claim
45 words
A surface wave resonator as claimed in claim 5 wherein each IDT is separated from an adjacent reflection grating with a separation of about 0.625λ+nλ/2, where λ is a wavelength of a surface wave to be propagated and n is zero or a positive integer.
Claim 8
Dependent Claim
22 words
A surface wave resonator as claimed in claim 5 wherein the two IDTs are separated from the reflection gratings with different separations.
Claim 9
Dependent Claim
30 words
A surface wave resonator as claimed in claim 5 wherein electrodes of at least one of the IDTs are arranged in spatial synchronism with adjacent fingers of the reflection gratings.
Claim 10
Dependent Claim
28 words
A surface wave resonator as claimed in claim 8 wherein electrodes of each of the IDTs are arranged in spatial synchronism with adjacent fingers of the reflection gratings.
Claim 11
Dependent Claim
56 words
A surface wave resonator as claimed in claim 8 wherein the resonant cavity for each IDT whose electrodes are arranged in spatial synchronism with adjacent fingers of the reflection gratings has a length of about 0.4375λ+nλ/2, where λ is a wavelength of a surface wave to be propagated and n is zero or a positive integer.
Claim 12
Dependent Claim
32 words
A surface wave resonator as claimed in claim 5 wherein each of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator.
Claim 13
Dependent Claim
18 words
A surface wave resonator as claimed in claim 11 wherein the common rail is divided into two halves.
Claim 14
Dependent Claim
53 words
A surface wave resonator as claimed in claim 5 wherein only one of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator, and the outer rail of the other IDT and the common rail provide an unbalanced signal connection to the resonator.
Claim 15
Dependent Claim
81 words
A double mode surface wave resonator comprising two IDTs (inter-digital transducers), arranged side by side between reflection gratings, on a surface of a piezoelectric substrate to provide for coupling of surface waves therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT, wherein at least one of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator.
Claim 16
Dependent Claim
81 words
A double mode surface wave resonator comprising two IDTs (inter-digital transducers), arranged side by side between reflection gratings, on a surface of a piezoelectric substrate to provide for coupling of surface waves therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT, wherein at least one of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator.
Claim 17
Dependent Claim
34 words
A double mode surface wave resonator as claimed in claim 14 wherein each of the IDTs and its outer rail is divided into two halves for providing a differential signal connection to the resonator.
Claim 18
Dependent Claim
32 words
A double mode surface wave resonator as claimed in claim 15 wherein electrodes of at least one of the IDTs are arranged in spatial synchronism with adjacent fingers of the reflection gratings.
Claim 19
Dependent Claim
28 words
A surface wave resonator as claimed in claim 15 wherein electrodes of each of the IDTs are arranged in spatial synchronism with adjacent fingers of the reflection gratings.
Claim 20
Dependent Claim
32 words
A double mode surface wave resonator as claimed in claim 14 wherein electrodes of at least one of the IDTs are arranged in spatial synchronism with adjacent fingers of the reflection gratings.
Claim 21
Dependent Claim
28 words
A surface wave resonator as claimed in claim 14 wherein electrodes of each of the IDTs are arranged in spatial synchronism with adjacent fingers of the reflection gratings.
Claim 22
Dependent Claim
80 words
A double mode surface wave resonator comprising two IDTs (inter-digital transducers), arranged side by side between reflection gratings comprising grounded fingers, on a surface of a piezoelectric substrate to provide for coupling of surface waves therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT, wherein electrodes of at least one of the IDTs are arranged in spatial synchronism with adjacent fingers of the reflection gratings.
Claim 23
Dependent Claim
80 words
A double mode surface wave resonator comprising two IDTs (inter-digital transducers), arranged side by side between reflection gratings comprising grounded fingers, on a surface of a piezoelectric substrate to provide for coupling of surface waves therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT, wherein electrodes of at least one of the IDTs are arranged in spatial synchronism with adjacent fingers of the reflection gratings.
Claim 24
Dependent Claim
28 words
A surface wave resonator as claimed in claim 20 wherein electrodes of each of the IDTs are arranged in spatial synchronism with adjacent fingers of the reflection gratings.
Claim 25
Dependent Claim
96 words
A double mode surface wave resonator comprising two IDTs (inter-digital transducers), arranged side by side between reflection gratings, on a surface of a piezoelectric substrate to provide for coupling surface surfaces therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT, wherein the electrodes of at least one of the IDTs are divided into two groups with a resonant cavity between the groups, and the electrodes of each group are arranged in spatial synchronism with adjacent fingers of the adjacent reflection grating.
Claim 26
Dependent Claim
96 words
A double mode surface wave resonator comprising two IDTs (inter-digital transducers), arranged side by side between reflection gratings, on a surface of a piezoelectric substrate to provide for coupling surface surfaces therebetween, each IDT having interleaved electrodes extending from a common rail between the two IDTs and from a respective outer rail of the IDT, wherein the electrodes of at least one of the IDTs are divided into two groups with a resonant cavity between the groups, and the electrodes of each group are arranged in spatial synchronism with adjacent fingers of the adjacent reflection grating.
Claim 27
Dependent Claim
48 words
A surface wave resonator as claimed in claim 22 wherein the electrodes of each of the IDTs are divided into two groups with a resonant cavity between the groups, and the electrodes of each group are arranged in spatial synchronism with adjacent fingers of the adjacent reflection grating.
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) | 1997-11-14 | 1998-05-16 | 1998-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-14 | 2002-05-16 | 2002-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-14 | 2006-05-16 | 2006-11-15 | $7700.00 | Window Closed / Lapsed |