Patent US5161255A successfully refreshed from Google Patents.
Patent US5381408A successfully refreshed from Google Patents.
US3602844A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Channel separating electrical wave filter
Assignee: AT&T Inc
•
Filing: 1969-10-06
•
Granted: 1971-08-31
•
Expires: 1989-10-06
Abstract
Abstract Multichannel signals on a single transmission path are separated into component channels by applying them to a pair of resonatorforming input electrodes mounted on a crystal wafer. Two or more groups of resonators, formed by other electrodes on the wafer, are each acoustically coupled to the input resonator but not to each other. The respective groups are tuned, by controlling the masses of the electrodes and the spacing between them, to form mutually exclusive passbands.
Inventors
- 👤 Roger A Sykes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:13
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/70; H03H9/703
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
113 words
A multichannel filter comprising an acoustically resonant wafer excitable in a thickness shear mode, first electrode means mounted on said wafer and forming with said wafer, when said wafer is excited, first resonator means; a first resonant system and a second resonant system each formed with portions of said wafer and each coupled through said wafer to said first resonator means; said resonant systems being spaced sufficiently far from each other on said wafer so as to be substantially decoupled from each other; said first resonant system when said wafer is excited forming a passband; said second resonant system when said wafer is excited forming a second passband exclusive of said first passband.
Claim 2
Dependent Claim
113 words
A multichannel filter comprising an acoustically resonant wafer excitable in a thickness shear mode, first electrode means mounted on said wafer and forming with said wafer, when said wafer is excited, first resonator means; a first resonant system and a second resonant system each formed with portions of said wafer and each coupled through said wafer to said first resonator means; said resonant systems being spaced sufficiently far from each other on said wafer so as to be substantially decoupled from each other; said first resonant system when said wafer is excited forming a passband; said second resonant system when said wafer is excited forming a second passband exclusive of said first passband.
Claim 3
Dependent Claim
76 words
A filter as in claim 1 wherein said resonant systems each include a plurality of resonant means formed on said wafer and including said wafer material and exhibiting respective resonant frequencies; said plurality of resonant means in said first resonant system being tuned and being spaced from one another to form said first passband; said plurality of resonant means in said second resonant system being tuned and spaced from one another to form said second passband.
Claim 4
Dependent Claim
75 words
A filter as in claim 2 wherein said resonant means and said resonator means each exhibit an electromechanical coupling limit; said resonant means of each system being coupled acoustically to other resonant means of the same system with a coupling less than the electromechanical coupling limit; one of said resonator means in each of said resonant systems each being coupled acoustically to said first resonator means, with a coupling less than the electromechanical coupling limit.
Claim 5
Dependent Claim
63 words
A filter as in claim 1, further comprising conductive means for applying high frequency electrical signals to said first electrode means; circuit means for connecting a resistive load to said first resonant system; said wafer exhibiting a characteristic resonant frequency in a thickness shear mode; said resonator means exhibiting when uncoupled a resonant frequency lower than the characteristic resonant frequency of said wafer.
Claim 6
Dependent Claim
62 words
A filter as in claim 2, further comprising conductive means for applying high frequency electrical signals to said first electrode means; circuit means for connecting a resistive load to said first resonant system; said wafer exhibiting a characteristic resonant frequency in a thickness shear mode; said resonator means exhibiting when uncoupled resonant frequencies lower than the characteristic resonant frequency of said wafer.
Claim 7
Dependent Claim
22 words
A filter as in claim 2 wherein said resonant means each include a pAir of electrodes on opposite faces of said wafer.
Claim 8
Dependent Claim
28 words
A filter as in claim 6 further comprising electrical means for adjusting the electromechanical coupling limit of at least one of said resonant means in said resonant systems.
Claim 9
Dependent Claim
19 words
A filter as in claim 7 wherein said electrical means include short circuits connecting the electrodes of each pair.
Claim 10
Dependent Claim
54 words
A filter as in claim 7 wherein said first circuit means connect to said electrode means of one of said resonant means in said first resonant system, and said second circuit means connects to said electrode means of one of said resonant, means in said second resonant system; said electrical means include an inductor.
Claim 11
Dependent Claim
53 words
A filter as in claim 1 wherein said first and second resonant systems include a plurality of resonators formed at least in part from said wafer and aligned in an elongated array; additional resonant systems including a plurality of resonators formed at least in part from said wafer and aligned in elongated arrays.
Claim 12
Dependent Claim
23 words
A filter as in claim 10, wherein said arrays are aligned relative to said first resonator means like the spokes of a wheel.
Claim 13
Dependent Claim
35 words
A filter as in claim 10, wherein said arrays are aligned parallel to each other and wherein said first resonator means include a pair of elongated electrodes forming a resonator coupled to all resonant systems.
Claim 14
Dependent Claim
20 words
A filter as in claim 2, wherein said resonant means are coupled acoustically less than one-half the electromechanical coupling limit.
Claim 15
Dependent Claim
29 words
A filter as in claim 1, wherein said resonant systems are spaced far enough from each other on said wafer so as to be substantially decoupled from each other.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-30 | 1975-03-01 | 1975-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-30 | 1979-03-01 | 1979-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-30 | 1983-03-01 | 1983-08-31 | $7700.00 | Window Closed / Lapsed |