US3626330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitive diode controlled oscillator frequency shift keying circuit
Assignee: MACKAY COMMUNICATIONS Inc CELWAVE SYSTEMS Inc PO BOX 39 CLARMONT NC 28610-0039 A CORP OF
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Filing: 1970-01-15
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Granted: 1971-12-07
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Expires: 1990-01-15
Abstract
Abstract A crystal oscillator is shifted between two different discrete frequencies by means of two different voltages being applied to a variable capacitance diode coupled in shunt relation with the crystal. The circuit providing one of the two different voltages having a given value is permanently connected to the diode to provide the lower frequency shift. The other of the two different voltages having a value greater than the given value is provided by a transistor stage under control of a binary signal. The binary signal controls the conduction and nonconduction of the transistor stage to selectively connect and disconnect the other of the two different voltages to the diode. This other higher voltage, and, therefore, the higher frequency shift, is provided only when the transistor stage is nonconductive, which occurs when the condition of the binary signal is low, and overcomes the voltage providing the lower frequency shift.
Inventors
- 👤 Robert A Zalonis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:35
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/10; H04L27/12; H03; H03C; H03C3/00; H03C3/10; H03C3/12; H03C3/22; H03C3/227
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
287 words
A circuit to shift the operating frequency of an oscillator between a first predetermined frequency and a second predetermined frequency different than said first frequency comprising: said oscillator including frequency-determining means, and frequency-controlling means coupled to said freQuencydetermining means; first means permanently connected to said frequency-controlling means to provide a first voltage therefore to shift the operating frequency of said oscillator to said first frequency; and second means selectively coupled to said frequency-controlling means to selectively apply a second voltage thereto to shift the operating frequency of said oscillator to said second frequency; said frequency-determining means including at least one crystal; said frequency-controlling means including a variable capacitance diode coupled in shunt relation with said crystal; said first means including ground potential, an operating voltage source, a first potentiometer having an adjustable terminal and two fixed terminals, said fixed terminals being coupled in series with said operating voltage source and said ground potential, and a first diode coupled between said adjustable terminal and said variable capacitance diode to provide said first voltage for said variable capacitance diode; and said second means including a control voltage source, said control voltage having a first amplitude and a second amplitude, a transistor having its base coupled to said control voltage source, its emitter coupled to said ground potential and its collector coupled to said operating voltage source, a second potentiometer having an adjustable terminal and two fixed terminals, said fixed terminals being coupled between the collector of said transistor and said ground potential, and a second diode coupled between said adjustable terminal of said second potentiometer and said variable capacitance diode to provide said second voltage for said variable capacitance diode only when said control voltage has said first amplitude.
Claim 2
Dependent Claim
287 words
A circuit to shift the operating frequency of an oscillator between a first predetermined frequency and a second predetermined frequency different than said first frequency comprising: said oscillator including frequency-determining means, and frequency-controlling means coupled to said freQuencydetermining means; first means permanently connected to said frequency-controlling means to provide a first voltage therefore to shift the operating frequency of said oscillator to said first frequency; and second means selectively coupled to said frequency-controlling means to selectively apply a second voltage thereto to shift the operating frequency of said oscillator to said second frequency; said frequency-determining means including at least one crystal; said frequency-controlling means including a variable capacitance diode coupled in shunt relation with said crystal; said first means including ground potential, an operating voltage source, a first potentiometer having an adjustable terminal and two fixed terminals, said fixed terminals being coupled in series with said operating voltage source and said ground potential, and a first diode coupled between said adjustable terminal and said variable capacitance diode to provide said first voltage for said variable capacitance diode; and said second means including a control voltage source, said control voltage having a first amplitude and a second amplitude, a transistor having its base coupled to said control voltage source, its emitter coupled to said ground potential and its collector coupled to said operating voltage source, a second potentiometer having an adjustable terminal and two fixed terminals, said fixed terminals being coupled between the collector of said transistor and said ground potential, and a second diode coupled between said adjustable terminal of said second potentiometer and said variable capacitance diode to provide said second voltage for said variable capacitance diode only when said control voltage has said first amplitude.
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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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |