Patent US4068198A successfully refreshed from Google Patents.
US4068198A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase-locked loop frequency shift key modulator
Assignee: General Dynamics Government Systems Corp
•
Filing: 1976-12-23
•
Granted: 1978-01-10
•
Expires: 1996-12-23
Abstract
Abstract MSK modulating apparatus employing a phase-locked loop. The loop includes a programmable divider which divides the output frequency of the voltage controlled oscillator by a relatively high value if binary 1 information is to be transmitted and by a relatively low value if binary 0 information is to be transmitted. The output of the voltage controlled oscillator is also divided by an output divider to obtain the desired carrier frequency and then filtered to provide a sinusoidal output signal. The resulting output signal varies by a differential frequency above or below a carrier center frequency when transmitting binary 1 or binary 0 data, respectively.
Inventors
- 👤 Jeffrey C. Otto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:18
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/02; H03C3/09; H03C3/0908; H03C3/0916; H03C3/0933; H03C3/0925; H04; H04L; H04L27/00; H04L27/18; H04L27/20; H04L27/2003; H04L27/2007; H04L27/2014; H03L; H03L7/00; H03L7/06; H03L7/16; H03L7/18; H03L7/197
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
350 words
Frequency shift key 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 preset value; phase detector means having a first input coupled to said means for providing 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 the preset value; first means for producing a first signal designating a first preset value; second means for producing a second signal designating a second preset value; and selection means coupled to said programmable dividing means and to said first and second means and being operable to receive data signals at a first level and data signals at a second level, said selection means being operable in response to receiving a data signal at the first level to apply said first signal designating a first preset value to said programmable dividing means and being operable in response to receiving a data signal at the second level to apply said second signal designating a second preset value to said programmable dividing means; whereby the output signal from the voltage controlled oscillator is at a first frequency when a data signal at the first level is being received by the selection means and the output signal from the voltage controlled oscillator is at a second frequency when a data signal at the second level is being received by the selection means; said selection means receiving continuous data signals, each data signal being present during a predetermined time interval, a data signal at said first level for said predetermined time interval representing a first binary digit and a data signal at said second level for said predetermined time interval representing a second binary digit.
Claim 2
Dependent Claim
350 words
Frequency shift key 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 preset value; phase detector means having a first input coupled to said means for providing 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 the preset value; first means for producing a first signal designating a first preset value; second means for producing a second signal designating a second preset value; and selection means coupled to said programmable dividing means and to said first and second means and being operable to receive data signals at a first level and data signals at a second level, said selection means being operable in response to receiving a data signal at the first level to apply said first signal designating a first preset value to said programmable dividing means and being operable in response to receiving a data signal at the second level to apply said second signal designating a second preset value to said programmable dividing means; whereby the output signal from the voltage controlled oscillator is at a first frequency when a data signal at the first level is being received by the selection means and the output signal from the voltage controlled oscillator is at a second frequency when a data signal at the second level is being received by the selection means; said selection means receiving continuous data signals, each data signal being present during a predetermined time interval, a data signal at said first level for said predetermined time interval representing a first binary digit and a data signal at said second level for said predetermined time interval representing a second binary digit.
Claim 3
Dependent Claim
156 words
Frequency shift key modulating apparatus in accordance with claim 1 wherein said first means produces a first signal designating a value of frequency which is greater than a center frequency by a specific amount; and said second means produces a second signal designating a value of frequency which is less than said center frequency by said specific amount; and 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 so that the frequency of the signal produced at the output of the output dividing means by a data signal at the first level received by the selection means differs from the frequency of the signal produced at the output of the output dividing means by a data signal at the second level received by the selection means by an amount equal to one-half the frequency of said data signals.
Claim 4
Dependent Claim
59 words
Frequency shift key modulating apparatus in accordance with claim 2 wherein said first and second means are operable to produce a set of first signals and a corresponding set of second signals, respectively, said first and second means being operable to produce particular first and second signals from said sets in response to input signals designating particular center frequencies.
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 |