US4068199A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital phase-locked loop frequency modulator
Assignee: General Dynamics Government Systems Corp
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Filing: 1976-12-23
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Granted: 1978-01-10
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Expires: 1996-12-23
Abstract
Abstract Frequency modulating apparatus employing a phase-locked loop. An analog signal is sampled periodically and each sample is converted to a digital signal by an analog-to-digital converter. A constant is added to the digital signal and the sum is employed as the divisor of a programmable divider connected in the phase-locked loop between the output of the voltage controlled oscillator and an input of a phase detector. The output of the voltage controlled oscillator is also divided by an output divider and then filtered to provide a sinusoidal output signal. The resulting output signal is at a center frequency which is frequency modulated by the analog signal.
Inventors
- 👤 Herbert S. Madoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:39
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/02; H03C3/09; H03C3/0908; H03C3/0916; H03C3/0933; H03C3/0925; H03L; H03L7/00; H03L7/06; H03L7/16; H03L7/18; H03L7/197
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
201 words
Frequency modulating apparatus including in combination means for producing a reference frequency signal; a voltage controlled oscillator; programmable dividing means coupled to the output of the voltage controlled oscillator for dividing the frequency of the output signal from the voltage controlled oscillator by a divisor; phase detector means having a first input coupled to said means for producing a reference frequency signal, a second input coupled to the output of said programmable dividing means, and an output coupled to the input of the voltage controlled oscillator to produce a phase-locked loop in which the frequency of the output signal from the voltage controlled oscillator is equal to the frequency of the reference frequency signal multiplied by said divisor; signal converting means for receiving an input signal and for converting the input signal to digital signals; storage means coupled to said signal converting means for holding a digital signal therefrom; and divisor means coupled to said storage means and to said programmable dividing means for applying to said programmable dividing means a divisor representing the digital signal held by said storage means, whereby the frequency of the output signal from the voltage controlled oscillator is modulated by the input signal being received.
Claim 2
Dependent Claim
201 words
Frequency modulating apparatus including in combination means for producing a reference frequency signal; a voltage controlled oscillator; programmable dividing means coupled to the output of the voltage controlled oscillator for dividing the frequency of the output signal from the voltage controlled oscillator by a divisor; phase detector means having a first input coupled to said means for producing a reference frequency signal, a second input coupled to the output of said programmable dividing means, and an output coupled to the input of the voltage controlled oscillator to produce a phase-locked loop in which the frequency of the output signal from the voltage controlled oscillator is equal to the frequency of the reference frequency signal multiplied by said divisor; signal converting means for receiving an input signal and for converting the input signal to digital signals; storage means coupled to said signal converting means for holding a digital signal therefrom; and divisor means coupled to said storage means and to said programmable dividing means for applying to said programmable dividing means a divisor representing the digital signal held by said storage means, whereby the frequency of the output signal from the voltage controlled oscillator is modulated by the input signal being received.
Claim 3
Dependent Claim
83 words
Frequency modulating apparatus in accordance with claim 1 wherein said signal converting means is operable to receive a continuous analog input signal and to convert the analog input signal to a series of digital signals; said storage means is operable to hold each digital signal from the signal converting means for a sample period; and said divisor means is operable to convert the digital signal held in said storage means to a divisor and to apply the divisor to said programmable dividing means.
Claim 4
Dependent Claim
76 words
Frequency modulating apparatus in accordance with claim 2 wherein said divisor means includes a source of a constant digital signal; and adding means coupled to said storage means, to said source of a constant digital signal, and to said programmable dividing means; said adding means being operable to add the constant digital signal from said source to the digital signal held in said storage means to produce the divisor being applied to the programmable dividing means.
Claim 5
Dependent Claim
35 words
Frequency modulating apparatus in accordance with claim 3 including output dividing means coupled to said voltage controlled oscillator for dividing the frequency of the output signal from the voltage controlled oscillator by a fixed amount.
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) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |