US3754192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromechanical frequency selective devices
Assignee: US Philips Corp
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Filing: 1972-01-05
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Granted: 1973-08-21
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Expires: 1992-01-05
Abstract
Abstract Electromechanical frequency selective filters are disclosed wherein a wafer of piezoelectric material converts an electric input signal into a surface wave by means of an input transducer comprising electrodes of conductive material on the surface of the wafer. The surface wave is converted into an electric output signal by means of an output transducer comprising two combshaped interdigital electrodes made of conductive material and arranged on the same surface of the wafer of piezoelectric material. Either or both of the transducers are split into a plurality of sub-electrodes which are electrically insulated from one another. Signals produced at output transducer sub-electrodes are separately applied to associated unidirectional amplifiers whose outputs are combined to obtain a desired overall output signal.
Inventors
- 👤 J Palfreeman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:29
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/74; H03H9/76; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/1208; H03H9/46; H03H9/64; H03H9/6403
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
136 words
Electromechanical filter employing elastic surface waves and comprising a wafer of a piezoelectric material provided with an input transducer for converting an electric input signal into a surface wave and with an output transducer for converting this surface wave into an electric output signal, the output transducer comprising two comb-shaped interdigital electrodes made of a conductive material and arranged on the same surface of the wafer of piezoelectric material, characterized in that one of the electrodes of the output transducer is split into a plurality of sub-electrodes, which are electrically insulated from one another, and in that the signals produced at these sub-electrodes are separately applied each to an associated unidirectional amplifier, the output signals of the unidirectional amplifiers being combined to obtain the desired overall output signal from the output transducer at an output terminal.
Claim 2
Dependent Claim
136 words
Electromechanical filter employing elastic surface waves and comprising a wafer of a piezoelectric material provided with an input transducer for converting an electric input signal into a surface wave and with an output transducer for converting this surface wave into an electric output signal, the output transducer comprising two comb-shaped interdigital electrodes made of a conductive material and arranged on the same surface of the wafer of piezoelectric material, characterized in that one of the electrodes of the output transducer is split into a plurality of sub-electrodes, which are electrically insulated from one another, and in that the signals produced at these sub-electrodes are separately applied each to an associated unidirectional amplifier, the output signals of the unidirectional amplifiers being combined to obtain the desired overall output signal from the output transducer at an output terminal.
Claim 3
Dependent Claim
45 words
Electromechanical filter as claimed in claim 1, characterized in that the output transducer has several output terminals from which, by making different combinations of the output signals of the separate unidirectional amplifiers, different combinations of the signals produced at the various sub-electrodes may be derived.
Claim 4
Dependent Claim
59 words
Electromechanical filter as claimed in claim 1, in which the input transducer also comprises two comb-shaped interdigital electrodes made of a conductive material, characterized in that one of the electrodes of the input transducer is split into a plurality of mutually electrically insulated sub-electrodes, the input signal being applied to each of these sub-electrodes through an associated unidirectional amplifier.
Claim 5
Dependent Claim
59 words
Electromechanical filter as claimed in claim 2, in which the input transducer also comprises two comb-shaped interdigital electrodes made of a conductive mAterial, characterized in that one of the electrodes of the input transducer is split into a plurality of mutually electrically insulated sub-electrodes, the input signal being applied to each of these sub-electrodes through an associated unidirectional amplifier.
References Cited (Backward Citations)
US3648081A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |