US5030926A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voltage controlled balanced crystal oscillator circuit
Assignee: Nokia Bell Labs
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Filing: 1990-07-10
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Granted: 1991-07-09
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Expires: 2010-07-10
Abstract
Abstract A voltage controlled crystal oscillator circuit, such as a Pierce oscillator circuit, includes an amplifier and is balanced by the addition of another varactor connected directly to the amplifier, whereby the frequency pull range is increased. Further, greater linearity can be achieved by adding another pair of varactors to the circuit.
Inventors
- 👤 Robert W. Walden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:41
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/36; H03B5/366; H03B5/368; H03B2200/00; H03B2200/0002; H03B2200/0012; H03B2200/003; H03B2200/004; H03B2200/006; H03B2200/0092; H03B2201/00; H03B2201/02; H03B2201/0208; Y; Y10; Y10S; Y10S331/00; Y10S331/03
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
199 words
A voltage controlled oscillator circuit comprising: (a) a crystal oscillator element having first and second terminals; (b) an amplifier having an input terminal connected to the first terminal of the crystal oscillator element and an output terminal connected to the second terminal for the crystal oscillator element; (c) a first varactor having one of its terminals connected directly to the input terminal of the amplifier and another of its terminals connected to a common node; (d) a second varactor having one of its terminals connected directly to the output terminal of the amplifier and another of its terminals connected directly to the common node; (e) means for applying a control voltage to the common node in order to pull the oscillation frequency of the oscillator element; (f) a third varactor having one of its terminals connected to the input terminal of the amplifier and another of its terminals connected to another common node; (g) a fourth varactor having one of its terminals connected to the output terminal of the amplifier and another of its terminals connected to said another common node; and (h) means for applying a bias voltage, different from the control voltage, to said another common node.
Claim 2
Dependent Claim
199 words
A voltage controlled oscillator circuit comprising: (a) a crystal oscillator element having first and second terminals; (b) an amplifier having an input terminal connected to the first terminal of the crystal oscillator element and an output terminal connected to the second terminal for the crystal oscillator element; (c) a first varactor having one of its terminals connected directly to the input terminal of the amplifier and another of its terminals connected to a common node; (d) a second varactor having one of its terminals connected directly to the output terminal of the amplifier and another of its terminals connected directly to the common node; (e) means for applying a control voltage to the common node in order to pull the oscillation frequency of the oscillator element; (f) a third varactor having one of its terminals connected to the input terminal of the amplifier and another of its terminals connected to another common node; (g) a fourth varactor having one of its terminals connected to the output terminal of the amplifier and another of its terminals connected to said another common node; and (h) means for applying a bias voltage, different from the control voltage, to said another common node.
Claim 3
Dependent Claim
17 words
The circuit of claim 1 and a utilization means connected to the output terminal of the amplifier.
Claim 4
Dependent Claim
17 words
The circuit of claim 1 and a utilization means connected to the input terminal of the amplifier.
Claim 5
Dependent Claim
17 words
The circuit of claim 3 and a utilization means connected to the output terminal of the amplifier.
Claim 6
Dependent Claim
78 words
The circuit of claim 1 in which the means for applying a bias voltage include: a first MOS transistor; a current source, connected to a high current-carrying-terminal of the first MOS transistor, for driving a constant current through the source-drain path of the first MOS transistor; resistive means to connect the common node to the gate terminal of the first MOS transistor; resistive means to connect said another node to the high-current-carrying terminal of the first MOS transistor.
Claim 7
Dependent Claim
16 words
The circuit of claim 5 and utilization means connected to the input terminal of the amplifier.
Claim 8
Dependent Claim
16 words
The circuit of claim 5 and utilization means connected to the output terminal of the amplifier.
Claim 9
Dependent Claim
16 words
The circuit of claim 7 and utilization means connected to the input terminal of the amplifier.
Claim 10
Dependent Claim
39 words
The circuit of claim 5 further comprising first and second resistors and a second MOS transistor mutually connected in series, the node between the first and second resistors being connected to the gate terminal of the first MOS transistor.
Claim 11
Dependent Claim
17 words
The circuit of claim 9 and a utilization means connected to the input terminal of the amplifier.
Claim 12
Dependent Claim
17 words
The circuit of claim 9 and a utilization means connected to the output terminal of the amplifier.
Claim 13
Dependent Claim
17 words
The circuit of claim 11 and a utilization means connected to the input terminal of the amplifier.
Claim 14
Dependent Claim
28 words
The voltage controlled oscillator circuit of claim 1 in which the capacitances of the first, second, third, and fourth varactors are mutually equal for any applied operating voltage.
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) | 1994-07-08 | 1995-01-07 | 1995-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-08 | 1999-01-07 | 1999-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-08 | 2003-01-07 | 2003-07-09 | $7700.00 | Window Closed / Lapsed |