US5166645A
Expired / Lapsed
US
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Differential mixer oscillator
Assignee: Delaware Capital Formation Inc
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Filing: 1992-01-15
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Granted: 1992-11-24
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Expires: 2012-01-15
Abstract
Abstract A differential mixer oscillator employing two transistors in a differential pair as the sustaining amplifier for a quartz crystal resonator at some first high frequency. The bias current of the differential pair is modulated at a second high frequency derived from some second frequency generating source, typically a second quartz crystal resonator, and the product terms are available at the collectors of the two transistors for selective filtering. The differential mixer oscillator may be employed in multiples, and with a variety of current sources, such as a Colpitts oscillator circuit.
Inventors
- 👤 Milton H. Watts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:36
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/36; H03D; H03D7/00; H03D7/14; H03D7/1425; H03D7/1433; H03B2200/00; H03B2200/0002; H03B2200/0008; H03B2200/0012; H03B2200/006; H03B2200/0098; H03D2200/00; H03D2200/0001; H03D2200/0033; H03D2200/0041; H03D2200/0043
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
100 words
An apparatus for sustaining the vibration of a first crystal resonator and for providing a mixed frequency output, comprising: first and second transistors arranged in a differential pair configuration as a sustaining amplifier for said first crystal resonator; a current source for providing a current having a first component and a second current component, said first current component being constant and of sufficient magnitude to sustain said vibration of said first crystal resonator substantially at a resonant frequency F1, and said second component being modulated at a second frequency F2; and impedance means for selectively filtering said mixed frequency output.
Claim 2
Independent Claim
100 words
An apparatus for sustaining the vibration of a first crystal resonator and for providing a mixed frequency output, comprising: first and second transistors arranged in a differential pair configuration as a sustaining amplifier for said first crystal resonator; a current source for providing a current having a first component and a second current component, said first current component being constant and of sufficient magnitude to sustain said vibration of said first crystal resonator substantially at a resonant frequency F1, and said second component being modulated at a second frequency F2; and impedance means for selectively filtering said mixed frequency output.
Claim 3
Dependent Claim
20 words
The apparatus of claim 1, further comprising means for providing biasing and phase shift for said differential pair of transistors.
Claim 4
Dependent Claim
17 words
The apparatus of claim 1, further comprising means for providing base bias for each of said transistors.
Claim 5
Dependent Claim
22 words
The apparatus of claim 1, wherein said current source comprises an oscillator circuit including a second crystal resonator and a third transistor.
Claim 6
Dependent Claim
14 words
The apparatus of claim 4, wherein said oscillator circuit comprises a Colpitts oscillator circuit.
Claim 7
Dependent Claim
22 words
The apparatus of claim 4, wherein the output current from said current source is taken from the collector of said third transistor.
Claim 8
Dependent Claim
25 words
The apparatus of claim 1, wherein said impedance means is selected from the group comprising a tuned LC circuit and an RC low pass filter.
Claim 9
Dependent Claim
15 words
The apparatus of claim 1, wherein said mixed frequency output is the difference frequency |F1-F2|.
Claim 10
Independent Claim
119 words
An apparatus for providing first and second mixed frequency outputs, comprising: a first DMO circuit including a first crystal resonator and a differential pair of transistors as a sustaining amplifier therefor; a second DMO circuit including a second crystal resonator and a differential pair of transistors as a sustaining amplifier therefor; means for providing a current to each of said first and second DMO's, said currents each including a constant current component for driving a said crystal resonator at a resonant frequency and a modulated current component of a different frequency than the resonant frequencies of either said first or said second crystal resonators; and means for selectively filtering the mixed frequency outputs of said first and second DMO's.
Claim 11
Independent Claim
119 words
An apparatus for providing first and second mixed frequency outputs, comprising: a first DMO circuit including a first crystal resonator and a differential pair of transistors as a sustaining amplifier therefor; a second DMO circuit including a second crystal resonator and a differential pair of transistors as a sustaining amplifier therefor; means for providing a current to each of said first and second DMO's, said currents each including a constant current component for driving a said crystal resonator at a resonant frequency and a modulated current component of a different frequency than the resonant frequencies of either said first or said second crystal resonators; and means for selectively filtering the mixed frequency outputs of said first and second DMO's.
Claim 12
Dependent Claim
38 words
The apparatus of claim 9, wherein said means for providing a current comprises an oscillator circuit including a third crystal resonator and two transistors, current being provided to each of said DMO's via one of said two transistors.
Claim 13
Dependent Claim
14 words
The apparatus of claim 10, wherein said oscillator circuit comprises a Colpitts oscillator circuit.
Claim 14
Dependent Claim
19 words
The apparatus of claim 10, wherein said current is provided to said DMO's via the collectors of said transistor.
Claim 15
Dependent Claim
41 words
The apparatus of claim 9, further including means for further isolating said first and second DMO's, said isolating means comprising transistor means placed in series with the current from said means for providing a current in a common base CASCODE configuration.
Claim 16
Dependent Claim
21 words
The apparatus of claim 9, further including means for providing a reference frequency output from said means for providing a current.
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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) | 1995-11-24 | 1996-05-25 | 1996-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-24 | 2000-05-25 | 2000-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-24 | 2004-05-25 | 2004-11-24 | $7700.00 | Window Closed / Lapsed |