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US4684903A
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Controlled oscillator having random variable frequency
Assignee: Mindspeed Technologies LLC
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Filing: 1984-04-30
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Granted: 1987-08-04
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Expires: 2004-04-30
Abstract
Abstract Method and apparatus for varying the output signal frequency of a controlled oscillator. The oscillator control signal is formed by filtering the output of a random number generator in such a way that the oscillatory output signal has a random frequency walk phase characteristic having predetermined, controlled characteristics.
Inventors
- 👤 Eugene V. Hunt
- 👤 Charles G. Mosley
- 👤 Charles E. Wheatley, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:14
CPC Classifications
H; H03; H03B; H03B29/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
99 words
Apparatus for generating an oscillatory output signal, comprising: an oscillator having means associated therewith for controlling and varying the frequency of said oscillatory output signal in response to variations of an oscillator input control signal; and means for generating said oscillator input control signal, comprising: a binary random number generator generating a sequence of pulses, V 1 , having a constant magnitude and randomly varying polarity; means for operating on V 1 according to the algorithm ##EQU11## wherein n is a positive interger; and means for scaling the magnitude of V n+1 to form said oscillator input control signal.
Claim 2
Dependent Claim
99 words
Apparatus for generating an oscillatory output signal, comprising: an oscillator having means associated therewith for controlling and varying the frequency of said oscillatory output signal in response to variations of an oscillator input control signal; and means for generating said oscillator input control signal, comprising: a binary random number generator generating a sequence of pulses, V 1 , having a constant magnitude and randomly varying polarity; means for operating on V 1 according to the algorithm ##EQU11## wherein n is a positive interger; and means for scaling the magnitude of V n+1 to form said oscillator input control signal.
Claim 3
Dependent Claim
24 words
The apparatus recited in claim 1, wherein said oscillatory output signal has a random frequency walk phase characteristic having a 1/f 2n noise spectrum.
Claim 4
Dependent Claim
102 words
The apparatus recited in claim 2, wherein said sequence of pulses is generated and propagated at a preselected repetition rate of 1/T per second, wherein e -sNT represents a time delay of NT seconds; wherein the frequency of said oscillatory output signal is changed by K hertz for each unit change in the value of V n+1 , and wherein T, N and K are jointly preselected to provide independently selected values for the mean square phase noise power, the mean square frequency noise power and the decorrelation time for said phase noise and said frequency noise in said oscillatory output signal.
Claim 5
Dependent Claim
19 words
The apparatus recited in claim 3, wherein said time delay is accomplished in a shift register having N cells.
Claim 6
Dependent Claim
14 words
The apparatus recited in claim 1, wherein said oscillator is a digital frequency synthesizer.
Claim 7
Dependent Claim
13 words
The apparatus recited in claim 1, wherein said oscillator is a voltage-controlled oscillator.
Claim 8
Dependent Claim
19 words
The apparatus recited in claim 6, wherein said means for scaling the magnitude V n+1 includes a digital-to-analog converter.
Claim 9
Dependent Claim
18 words
The apparatus recited in claim 1, wherein said binary random number generator is a pseudo random number generator.
Claim 10
Dependent Claim
39 words
The apparatus recited in claim 8, wherein said pseudo random number generator comprises a shift register, wherein two or more cells of said shift register are summed, and wherein this sum is fed back into said shift register's inputs.
Claim 11
Independent Claim
164 words
A method of generating a control signal for an oscillator having a controllably variable output signal frequency, comprising the steps of: selecting n for a random frequency walk having a 1/f 2n noise spectrum, wherein n is a positive integer; generating a sequence of pulses, V 1 , having a constant magnitude and randomly varying polarity, wherein said pulses are generated at a preselected repetition rate of 1/T per second; providing a filter having a weighted shift register and adder structure, said filter operating on V 1 according to the algorithm ##EQU12## wherein N is a preselected positive number and e -sNT represents a time delay of NT seconds; and scaling the magnitude of V n+1 to form an input control signal for said oscillator, wherein a unit change in the value of V n+1 changes said input control signal by an amount which varies the frequency of said oscillatory output signal by K radians per second, wherein K is a preselected positive number.
Claim 12
Independent Claim
164 words
A method of generating a control signal for an oscillator having a controllably variable output signal frequency, comprising the steps of: selecting n for a random frequency walk having a 1/f 2n noise spectrum, wherein n is a positive integer; generating a sequence of pulses, V 1 , having a constant magnitude and randomly varying polarity, wherein said pulses are generated at a preselected repetition rate of 1/T per second; providing a filter having a weighted shift register and adder structure, said filter operating on V 1 according to the algorithm ##EQU12## wherein N is a preselected positive number and e -sNT represents a time delay of NT seconds; and scaling the magnitude of V n+1 to form an input control signal for said oscillator, wherein a unit change in the value of V n+1 changes said input control signal by an amount which varies the frequency of said oscillatory output signal by K radians per second, wherein K is a preselected positive number.
Claim 13
Dependent Claim
52 words
The method recited in claim 10, further comprising the step of jointly selecting T, N and K to provide independently selected values for the mean square phase noise power, the mean square frequency noise power and the decorrelation time for said phase noise and said frequency noise in said oscillatory output signal.
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) | 1990-08-03 | 1991-02-02 | 1991-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-03 | 1995-02-02 | 1995-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-03 | 1999-02-02 | 1999-08-04 | $7700.00 | Window Closed / Lapsed |