US3809931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature-stabilized transducer device
Assignee: United States Department of the Navy
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Filing: 1973-03-19
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Granted: 1974-05-07
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Expires: 1993-03-19
Abstract
Abstract A transducer device comprising a substrate capable of propagating an elastic wave on its surface. A resistive film is disposed generally centrally upon the substrate, the film having a grounded lead on one side of the film and an ungrounded lead on the other side of the film. At least one active-channel transducer is disposed on the substrate, for processing a surface-elastic wave, each transducer comprising an input activechannel transducer, disposed on one side, the input side of the resistive film, and an output active-channel transducer, disposed on the other side, the output side, of the resistive film. A reference-channel transducer, also disposed on the substrate, comprises an input reference-channel transducer, disposed on the input side of the film, and connectable to a reference signal source, which causes an elastic surface wave to propagate across the substrate including the area occupied by the resistive film; and an output reference-channel transducer, having an output lead, and disposed on the output side of the film. The combination comprises a surface-wave transducer device which may be temperature-stabilized.
Inventors
- 👤 R White
- 👤 R Goyal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:21
CPC Classifications
H; H03; H03H; H03H3/00; H03H3/007; H03H3/08; H03H3/10; H03H9/00; H03H9/30; H03H9/42; H03H9/44
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
331 words
A transducer device comprising: a substrate capable of propagating an elastic wave on its surface; a resistive film, disposed upon the substrate, of substantially rectangular shape, with the longer sides of the rectangle parallel to the direction of propagation of the wave, one of short sides of the rectangle determining an input side of the film, the other short-side determining an output side, the film having a grounded lead connected to one of the longer sides of the film and an ungrounded lead connected to the other longer side of the film; at least one active-channel transducer disposed on the substrate, for processing a surface-elastic wave, each transducer comprising: an input active-channel transducer, disposed on the input side of the resistive film; and an output active-channel transducer, disposed on the output side of the resistive film; and a reference-channel transducer, disposed on the substrate, comprising: an input reference-channel transducer, disposed on the input side of the film, and connectable to a reference signal source, which causes an elastic surface wave to propagate across the substrate, including the area occupied by the resistive film; and an output reference-channel transducer, having an output lead, and disposed on the output side of the film; a phase comparator, having inputs from the input and output reference-channel transducers, for sensing the change in the phase length of the signal generated by the reference signal source, which traverses the reference channel, the path on the substrate aligned with the input and output reference channel transducers; the output of the phase comparator being connected to the ungrounded lead of the resistive film; the output voltage of the phase comparator causing current to flow in the resistive film, which in turn causes increased or decreased heating of the surface of the substrate in a manner to decrease the change in the phase length of the reference signal traversing the reference channel; and therefore of the elastic waves processed by the activechannel transducers; the combination comprising a temperature-stabilized transducer device.
Claim 2
Dependent Claim
331 words
A transducer device comprising: a substrate capable of propagating an elastic wave on its surface; a resistive film, disposed upon the substrate, of substantially rectangular shape, with the longer sides of the rectangle parallel to the direction of propagation of the wave, one of short sides of the rectangle determining an input side of the film, the other short-side determining an output side, the film having a grounded lead connected to one of the longer sides of the film and an ungrounded lead connected to the other longer side of the film; at least one active-channel transducer disposed on the substrate, for processing a surface-elastic wave, each transducer comprising: an input active-channel transducer, disposed on the input side of the resistive film; and an output active-channel transducer, disposed on the output side of the resistive film; and a reference-channel transducer, disposed on the substrate, comprising: an input reference-channel transducer, disposed on the input side of the film, and connectable to a reference signal source, which causes an elastic surface wave to propagate across the substrate, including the area occupied by the resistive film; and an output reference-channel transducer, having an output lead, and disposed on the output side of the film; a phase comparator, having inputs from the input and output reference-channel transducers, for sensing the change in the phase length of the signal generated by the reference signal source, which traverses the reference channel, the path on the substrate aligned with the input and output reference channel transducers; the output of the phase comparator being connected to the ungrounded lead of the resistive film; the output voltage of the phase comparator causing current to flow in the resistive film, which in turn causes increased or decreased heating of the surface of the substrate in a manner to decrease the change in the phase length of the reference signal traversing the reference channel; and therefore of the elastic waves processed by the activechannel transducers; the combination comprising a temperature-stabilized transducer device.
Claim 3
Dependent Claim
13 words
The transducer device according to claim 1 further comprising: the reference signal source.
Claim 4
Dependent Claim
17 words
The transducer device according to claim 3, wherein the reference signal source is Disposed upon the substrate.
Claim 5
Dependent Claim
54 words
The transducer device according to claim 4, wherein the reference signal source comprises: an input transducer; and an output transducer; an amplifier whose input is connected to the output of the output transducer and whose output is connected to the input of the input transducer; the reference signal source thereby comprising a feedback oscillator.
Claim 6
Dependent Claim
19 words
The transducer device according to claim 5, wherein the input and output transducers comprise a pair of interdigitated transducers.
Claim 7
Dependent Claim
28 words
The transducer device according to claim 1, further comprising: a direct-current amplifier connected between the output of the phase comparator and the ungrounded lead of the resistive film.
Claim 8
Dependent Claim
24 words
The transducer device according to claim 6, further comprising: a direct-current amplifier connected between the output of the phase comparator and the ungrounded lead.
Claim 9
Dependent Claim
52 words
The transducer device according to claim 7, wherein the substrate is a yz-cut lithium niobate crystal; the transducers have parameters designed for operation in the range of 78 MHz; and the resistive film is sputtered tantalum approximately 500 A. thick, having a terminal resistance of approximately 200 ohms, and rectangular in shape.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-06 | 1977-11-05 | 1978-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-06 | 1981-11-05 | 1982-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-06 | 1985-11-05 | 1986-05-07 | $7700.00 | Window Closed / Lapsed |