US3936765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface acoustic wave oscillators
Assignee: National Research Development Corp UK
•
Filing: 1974-06-04
•
Granted: 1976-02-03
•
Expires: 1994-06-04
Abstract
Abstract A surface acoustic wave oscillator comprises a surface acoustic wave delay line and amplifier. The phase difference between signals received from two transducers on the surface acoustic wave delay line is measured by a phase sensitive detector whose output is used to control a phase correction circuit. The oscillator may oscillate at a steady frequency or be frequency modulated.
Inventors
- 👤 Meirion Francis Lewis
- 👤 James Dennis Maines
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:02
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/30; H03H9/42; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/326; H03H9/02; H03H9/02535; H03H9/0296; H03H9/74; H03H9/76
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
110 words
An acoustic wave oscillator comprising a surface acoustic wave delay line having an input transducer and an output transducer mounted on a substrate capable of supporting acoustic waves, an amplifier circuit having its input connected to the output of the output transducer, and its output connected to the input of the input transducer a phase sensitive detector for measuring the phase difference between signals received from two transducers mounted on the substrate and giving an output dependent on said phase difference, and means controlled by the phase sensitive detector for applying to the amplifier circuit a correcting signal to maintain a desired phase difference measured by the phase sensitive detector.
Claim 2
Dependent Claim
110 words
An acoustic wave oscillator comprising a surface acoustic wave delay line having an input transducer and an output transducer mounted on a substrate capable of supporting acoustic waves, an amplifier circuit having its input connected to the output of the output transducer, and its output connected to the input of the input transducer a phase sensitive detector for measuring the phase difference between signals received from two transducers mounted on the substrate and giving an output dependent on said phase difference, and means controlled by the phase sensitive detector for applying to the amplifier circuit a correcting signal to maintain a desired phase difference measured by the phase sensitive detector.
Claim 3
Dependent Claim
20 words
An oscillator as claimed in claim 1 wherein the phase sensitive detector is connected to the input and output transducers.
Claim 4
Dependent Claim
34 words
An oscillator as claimed in claim 1 wherein the phase sensitive detector is connected to the input transducer and to a second output transducer arranged to receive surface acoustic waves from the input transducer.
Claim 5
Dependent Claim
20 words
An oscillator as claimed in claim 1 wherein the means for applying a correcting signal is a phase shift circuit.
Claim 6
Dependent Claim
82 words
An oscillator as claimed in claim 1 wherein the means for applying a correcting signal includes a second output transducer arranged on the substrate to receive surface acoustic waves from the input transducer out of phase relative to those received by the other output transducer, and a variable impedance connected between the second output transducer and the amplifier circuit input whereby under the control of the phase sensitive detector a variable amplitude out of phase signal is applied to the amplifier circuit.
Claim 7
Dependent Claim
24 words
An oscillator as claimed in claim 1 which further includes means for applying a signal to the oscillator to produce a frequency modulation thereof.
Claim 8
Dependent Claim
57 words
An oscillator as claimed in claim 6 wherein the signal applying means is a differential amplifier having a first input connected to the phase sensitive detector output, a second input to which the signals for producing frequency modulation may be applied, and an output connected to the means for applying a correcting signal to the amplifier circuit.
Claim 9
Dependent Claim
23 words
An oscillator as claimed in claim 1 wherein the phase sensitive detector is arranged to have a linear output over its operating range.
Claim 10
Dependent Claim
25 words
An oscillator as claimed in claim 6, wherein the time constant of the phase sensitive detector is much longer than the inverse of modulation frequencies.
Claim 11
Dependent Claim
25 words
An oscillator as claimed in claim 6 wherein the time constant of the phase sensitive detector is much shorter than the inverse of modulation frequencies.
Claim 12
Dependent Claim
12 words
An oscillator as claimed in claim 1 wherein the substrate is piezoelectric.
References Cited (Backward Citations)
US3582540A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-02 | 1979-08-04 | 1980-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-02 | 1983-08-04 | 1984-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-02 | 1987-08-04 | 1988-02-03 | $7700.00 | Window Closed / Lapsed |