US3836873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low noise vhf crystal harmonic oscillator
Assignee: Westinghouse Electric Corp
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Filing: 1973-07-02
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Granted: 1974-09-17
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Expires: 1993-07-02
Abstract
Abstract A two transistor VHF crystal controlled harmonic oscillator provides a large ratio of output power to crystal unit power dissipation without significant degradation of oscillating resonator Q from the crystal unit Q defined herein as Qx. A cascode amplifier configuration comprising first and second transistors in combination with inductance and capacitance elements provides an oscillator configuration with phase shift in the vicinity of the oscillator frequency dominantly controlled by the quartz crystal unit motional impedance parameters. The first and second transistors are operated under linear conditions during the complete cycle of oscillation current, and two hot carrier diodes operated with appropriate biasing voltages provides the limiting characteristic required in harmonic oscillators. Circuit applications may use one or two VHF crystal units with appropriate antiresonating of circuit capacitance to achieve a desired minimum of phase noise power spectral density in the oscillator circuit.
Inventors
- 👤 D Healey
- 👤 M Driscoll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:42
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/36; H03B19/00; H03B19/16; H03B2200/00; H03B2200/0002; H03B2200/0004; H03B2200/0008; H03B2200/0012; H03B2200/0014; H03B2200/0018; H03B2200/006; H03B2200/007; H03B2200/0088; H03B2200/009; H03B2202/00; H03B2202/08; H03B2202/082; H03B2202/086
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
168 words
An oscillator circuit for generating a low noise, high frequency output signal, said oscillator circuit comprising: a. first and second amplifier means, each having first and third terminals for receiving an input whereby an output derived from its second termInal is determined, said third terminal of said second amplifier means coupled to said second terminal of said first amplifier means; b. a first resonant circuit coupled to said second terminal of said second amplifier means and to said first terminal of said first amplifier means, whereby a resonating signal is established between said first resonating circuit and said first and second amplifier means; and c. a second resonant circuit coupled to said third terminal of said first amplifier means and including a capacitive element, an inductive element and a reference frequency element, for establishing the frequency of the resonating signal through said first and second amplifier means, the values of said inductive and capacitive elements selected to establish antiresonance therein at the reference frequency of said reference element.
Claim 2
Dependent Claim
168 words
An oscillator circuit for generating a low noise, high frequency output signal, said oscillator circuit comprising: a. first and second amplifier means, each having first and third terminals for receiving an input whereby an output derived from its second termInal is determined, said third terminal of said second amplifier means coupled to said second terminal of said first amplifier means; b. a first resonant circuit coupled to said second terminal of said second amplifier means and to said first terminal of said first amplifier means, whereby a resonating signal is established between said first resonating circuit and said first and second amplifier means; and c. a second resonant circuit coupled to said third terminal of said first amplifier means and including a capacitive element, an inductive element and a reference frequency element, for establishing the frequency of the resonating signal through said first and second amplifier means, the values of said inductive and capacitive elements selected to establish antiresonance therein at the reference frequency of said reference element.
Claim 3
Dependent Claim
41 words
The oscillator circuit as claimed in claim 1, wherein said first and second amplifier means each comprises a transistor having base, emitter and collector elements, said emitter element of said second transistor coupled to said collector element of said first transistor.
Claim 4
Dependent Claim
25 words
An oscillator circuit as claimed in claim 2, wherein said collector of said first transistor is directly connected to said emitter of said second transistor.
Claim 5
Dependent Claim
18 words
The oscillator circuit as claimed in claim 1, wherein the reference frequency element comprises a quartz crystal unit.
Claim 6
Dependent Claim
19 words
The oscillator circuit as claimed in claim 1, wherein the reference frequency element comprises an AT-cut overtone crystal unit.
Claim 7
Dependent Claim
55 words
The oscillator circuit as claimed in claim 1, wherein there is further included a limiting circuit coupled to said third terminal of said second amplifier means for establishing a range of voltages in which said first and second amplifier means may be driven without reaching the saturation limits of said first and second amplifier means.
Claim 8
Dependent Claim
38 words
The oscillator circuit as claimed in claim 5, wherein said limiting circuit includes first and second unidirectional conducting means coupled respectively to low noise power sources of first and second levels corresponding to the limits of said range.
Claim 9
Dependent Claim
65 words
The oscillator circuit as claimed in claim 1, wherein said first resonant circuit includes a first capacitive element coupled to said first terminal of said first amplifier means, an inductive element coupled between said first terminal of said first amplifier means and said second terminal of said second amplifier means, and a second capacitive element connected to said second terminal of said second amplifier means.
Claim 10
Dependent Claim
37 words
The oscillator circuit as claimed in claim 1, wherein said second resonant circuit further includes a second reference element connected in series with said first reference frequency element, to said third terminal of said first amplifier means.
Claim 11
Dependent Claim
69 words
The oscillator circuit as claimed in claim 9, wherein said second reference frequency element has a third resonant circuit including an inductive element and a capacitive element connected in parallel thereto, the values of the elements of said second and third resonant circuits selected to antiresonate the electrostatic capacitance of said first and second reference frequency elements at the resonating frequencies of said first and second reference frequency elements.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |