Patent US4910470A successfully refreshed from Google Patents.
US4910470A
Expired / Lapsed
US
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Digital automatic frequency control of pure sine waves
Assignee: Motorola Solutions Inc
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Filing: 1988-12-16
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Granted: 1990-03-20
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Expires: 2008-12-16
Abstract
Abstract There is provided a method of and apparatus for Automatic Frequency Control (AFC) of pure sine waves (PSW). It comprises discriminating to detect frequency differences between a received pure sine wave and a reference frequency, integrating the frequency differences to average the differences, and adjusting the reference frequency to eliminate the frequency difference. It is further characterized by digitizing, in quadrature, the received pure sine wave, mixing the received pure sine wave with a complex sinusoid to translate the pure sine wave to baseband, quadrature filtering the mixed sine wave, cross-product discriminating to detect frequency differences between a received pure sine wave and a reference frequency, integrating the frequency differences to average the differences, selectively calculating the mean variance between the pure sine wave and the reference frequency, and adjusting the reference frequency of a Voltage Controlled Oscillator to eliminate the frequency difference.
Inventors
- 👤 David E. Borth
- 👤 James F. M. Kepler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:10
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03J; H03J7/00; H03J7/02; H03L7/085; H03L7/087; H03J7/026
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
53 words
A method of digital Automatic Frequency Control (AFC) on pure sine waves (PSW) comprising: discriminating, with reference to a reference frequency, to detect frequency differences between a received pure sine wave and a reference waveform, integrating the frequency differences to average the differences, and adjusting the reference frequency to eliminate the frequency difference.
Claim 2
Independent Claim
53 words
A method of digital Automatic Frequency Control (AFC) on pure sine waves (PSW) comprising: discriminating, with reference to a reference frequency, to detect frequency differences between a received pure sine wave and a reference waveform, integrating the frequency differences to average the differences, and adjusting the reference frequency to eliminate the frequency difference.
Claim 3
Dependent Claim
13 words
The method as claimed in claim 1, wherein discrimination further comprises cross-product discrimination.
Claim 4
Dependent Claim
30 words
The method as claimed in claim 1, wherein discrimination is preceded by mixing the received pure sine wave with a complex sinusoid reference waveform to translate it to 0 Hz.
Claim 5
Dependent Claim
21 words
The method as claimed in claim 3, wherein quadrature filtering of the mixed sine wave is interposed between mixing and discrimination.
Claim 6
Dependent Claim
20 words
The method as claimed in claim 3, wherein mixing is preceded by digitizing, in quadrature, the received pure sine wave.
Claim 7
Dependent Claim
24 words
The method as claimed in claim 1, wherein adjustment further comprises adjusting the frequency of a Voltage Controlled Oscillator to eliminate the frequency difference.
Claim 8
Dependent Claim
27 words
The method as claimed in claim 1, wherein the variance between the pure sine wave and the reference waveform is utilized to selectively invoke the frequency adjustment.
Claim 9
Dependent Claim
26 words
The method as claimed in claim 1, wherein marginal variances between the pure sine wave and the reference waveform are utilized to invoke the frequency adjustment.
Claim 10
Dependent Claim
26 words
The method as claimed in claim 1, wherein substantial variances between the pure sine wave and the reference waveform are utilized to suspend the frequency adjustment.
Claim 11
Independent Claim
61 words
A method of digital Automatic Frequency Control (AFC) on bursted pure sine waves (PSW) comprising: cross-product discriminating, with reference to a reference frequency, to detect frequency differences between a received pure sine wave burst and a reference waveform, integrating the frequency differences to average the differences, and adjusting the frequency of a Voltage Controlled Oscillator reference to eliminate the frequency difference.
Claim 12
Independent Claim
61 words
A method of digital Automatic Frequency Control (AFC) on bursted pure sine waves (PSW) comprising: cross-product discriminating, with reference to a reference frequency, to detect frequency differences between a received pure sine wave burst and a reference waveform, integrating the frequency differences to average the differences, and adjusting the frequency of a Voltage Controlled Oscillator reference to eliminate the frequency difference.
Claim 13
Independent Claim
86 words
A method of digital Automatic Frequency Control (AFC) on bursted pure sine waves (PSW) comprising: digitizing, in quadrature, the received pure sine wave, mixing the received pure sine wave with a complex sinusoid reference waveform to translate it to 0 Hz, quadrature filtering the mixed sine wave, cross-product discriminating to detect frequency differences between a received pure sine wave and the reference waveform, integrating the frequency differences to average the differences, and adjusting the frequency of a Voltage Controlled Oscillator reference to eliminate the frequency difference.
Claim 14
Independent Claim
86 words
A method of digital Automatic Frequency Control (AFC) on bursted pure sine waves (PSW) comprising: digitizing, in quadrature, the received pure sine wave, mixing the received pure sine wave with a complex sinusoid reference waveform to translate it to 0 Hz, quadrature filtering the mixed sine wave, cross-product discriminating to detect frequency differences between a received pure sine wave and the reference waveform, integrating the frequency differences to average the differences, and adjusting the frequency of a Voltage Controlled Oscillator reference to eliminate the frequency difference.
Claim 15
Independent Claim
103 words
A method of digital Automatic Frequency Control (AFC) on bursted pure sine waves (PSW) comprising: digitizing, in quadrature, the received pure sine wave, mixing the received pure sine wave with a complex sinusoid reference waveform to translate it to 0 Hz, quadrature filtering the mixed sine wave, cross-product discriminating to detect frequency differences between a received pure sine wave and the reference waveform, integrating the frequency differences to average the differences, adjusting the frequency of a Voltage Controlled Oscillator reference to eliminate the frequency difference, and selected invoking frequency adjustment based upon the variances between the pure sine wave and the reference waveform.
Claim 16
Independent Claim
103 words
A method of digital Automatic Frequency Control (AFC) on bursted pure sine waves (PSW) comprising: digitizing, in quadrature, the received pure sine wave, mixing the received pure sine wave with a complex sinusoid reference waveform to translate it to 0 Hz, quadrature filtering the mixed sine wave, cross-product discriminating to detect frequency differences between a received pure sine wave and the reference waveform, integrating the frequency differences to average the differences, adjusting the frequency of a Voltage Controlled Oscillator reference to eliminate the frequency difference, and selected invoking frequency adjustment based upon the variances between the pure sine wave and the reference waveform.
Claim 17
Independent Claim
62 words
An apparatus for digital Automatic Frequency Control (AFC) of pure sine waves (PSW) comprising, coupled in series: means for discriminating, with reference to a reference frequency, to detect frequency differences between a received pure sine wave and a reference waveform, and means for integrating the frequency differences to average the differences and for adjusting the reference frequency to eliminate the frequency difference.
Claim 18
Independent Claim
62 words
An apparatus for digital Automatic Frequency Control (AFC) of pure sine waves (PSW) comprising, coupled in series: means for discriminating, with reference to a reference frequency, to detect frequency differences between a received pure sine wave and a reference waveform, and means for integrating the frequency differences to average the differences and for adjusting the reference frequency to eliminate the frequency difference.
Claim 19
Independent Claim
100 words
An apparatus for digital Automatic Frequency Control (AFC) of pure sine waves (PSW) comprising, coupled in series: means for digitizing, in quadrature, the received pure sine wave, means for mixing the received pure sine wave with a complex sinusoid reference waveform to translate it to 0 Hz, means for quadrature filtering the mixed sine wave, means for cross-product discriminating to detect frequency differences between a received pure sine wave and the reference waveform, and means for integrating the frequency differences to average the differences and for adjusting the frequency of a Voltage Controlled Oscillator reference to eliminate the frequency difference.
Claim 20
Independent Claim
100 words
An apparatus for digital Automatic Frequency Control (AFC) of pure sine waves (PSW) comprising, coupled in series: means for digitizing, in quadrature, the received pure sine wave, means for mixing the received pure sine wave with a complex sinusoid reference waveform to translate it to 0 Hz, means for quadrature filtering the mixed sine wave, means for cross-product discriminating to detect frequency differences between a received pure sine wave and the reference waveform, and means for integrating the frequency differences to average the differences and for adjusting the frequency of a Voltage Controlled Oscillator reference to eliminate the frequency difference.
Claim 21
Independent Claim
120 words
An apparatus for digital Automatic Frequency Control (AFC) of pure sine waves (PSW) comprising, coupled in series: means for digitizing, in quadrature, the received pure sine wave, means for mixing the received pure sine wave with a complex sinusoid reference waveform to translate it to 0 Hz, means for quadrature filtering the mixed sine wave, means for cross-product discriminating to detect frequency differences between a received pure sine wave and the reference waveform, means for integrating the selected frequency differences to average the differences and for adjusting the frequency of a Voltage Controlled Oscillator reference to eliminate the frequency difference, and means for selectively invoking frequency adjustment based upon the variances between the pure sine wave and the reference waveform.
Claim 22
Independent Claim
120 words
An apparatus for digital Automatic Frequency Control (AFC) of pure sine waves (PSW) comprising, coupled in series: means for digitizing, in quadrature, the received pure sine wave, means for mixing the received pure sine wave with a complex sinusoid reference waveform to translate it to 0 Hz, means for quadrature filtering the mixed sine wave, means for cross-product discriminating to detect frequency differences between a received pure sine wave and the reference waveform, means for integrating the selected frequency differences to average the differences and for adjusting the frequency of a Voltage Controlled Oscillator reference to eliminate the frequency difference, and means for selectively invoking frequency adjustment based upon the variances between the pure sine wave and the reference waveform.
Claim 23
Independent Claim
55 words
A method of digital Automatic Frequency Control (AFC) on bursted pure sine waves (PSW) comprising: discriminating, with reference to a reference frequency, to detect frequency differences between a received pure sine wave burst and a reference waveform, integrating the frequency differences to average the differences, and adjusting the reference frequency to eliminate the frequency difference.
Claim 24
Independent Claim
55 words
A method of digital Automatic Frequency Control (AFC) on bursted pure sine waves (PSW) comprising: discriminating, with reference to a reference frequency, to detect frequency differences between a received pure sine wave burst and a reference waveform, integrating the frequency differences to average the differences, and adjusting the reference frequency to eliminate the frequency difference.
References Cited (Backward Citations)
US3403355A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-03-19 | 1993-09-18 | 1994-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-19 | 1997-09-18 | 1998-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-19 | 2001-09-18 | 2002-03-20 | $7700.00 | Window Closed / Lapsed |