US3576453A
Expired / Lapsed
US
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Monolithic electric wave filters
Assignee: AT&T Inc
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Filing: 1969-05-02
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Granted: 1971-04-27
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Expires: 1989-05-02
Abstract
Abstract A crystal wafer supports two or more pairs of opposing electrodes to form a monolithic crystal filter. The wafer material has a high piezoelectric coupling coefficient. Inharmonic oscillations are suppressed by plating the electrodes on the surfaces of recesses in the faces of the wafer.
Inventors
- 👤 Warren P Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:13
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/56; H03H9/566
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
30 words
A resonator as in claim 1 wherein said third region supports second electrode means whereby energy applied at said first electrode means may be sensed at said second electrode means.
Claim 2
Dependent Claim
47 words
A resonator as in claim 1 further comprising a plurality of additional regions each surrounded by said second region and thinner than said second region, said regions being acoustically coupled to each other through said second region when said wafer is excited in a thickness shear mode.
Claim 3
Dependent Claim
34 words
A resonator as in claim 3 wherein said first region and said plurality of additional regions form respective resonator means coupled to at least one of said other resonator means through said second region.
Claim 4
Dependent Claim
36 words
A resonator as in claim 4 wherein one of said plurality of regions supports electrode means and wherein energy applied to one of said electrode means maY be sensed by the other of said electrode means.
Claim 5
Dependent Claim
50 words
A resonator as in claim 5 wherein the remainder of said regions surrounded by said second region each support electrode means and wherein said electrode means each comprise a pair of electrode plates and wherein the plates of the electrode means on the remaining ones of said regions are short-circuited.
Claim 6
Dependent Claim
44 words
A resonator as in claim 2 wherein said resonator means when said wafer is excited in a thickness shear mode exhibit two resonant frequencies and at least one antiresonant frequency and wherein said antiresonant frequency is higher than either one of said resonant frequencies.
Claim 7
Dependent Claim
44 words
A resonator as in claim 2 wherein said resonant means exhibit when said wafer is excited in the thickness shear mode two resonant frequencies and two antiresonant frequencies and wherein said resonant frequencies are each lower in frequency than each of said antiresonant frequencies.
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) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |