US4213097A
Expired / Lapsed
US
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Hybrid automatic gain control circuit
Assignee: Racal Data Communications Inc
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Filing: 1978-10-19
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Granted: 1980-07-15
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Expires: 1998-10-19
Abstract
Abstract An automatic gain control circuit having a coarse analog gain adjustment section producing discrete increments of db gain and a fine digital gain adjustment section. The digital section provides for adjustment of gain through a final increment of db gain to achieve precise gain setting. The output of the digital section is squared and compared to a reference signal to derive an error signal whose value is fed to an apparatus which iteratively determines the precise coarse increment and fine digital settings to achieve the final desired gain setting.
Inventors
- 👤 Ran F. Chiu
- 👤 Philip F. Kromer, III
- 👤 Ming L. Kao
- 👤 Henry H. Parrish
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:12
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/001; H03G3/20; H03G3/30
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
82 words
An automatic gain control circuit for controlling the gain provided to an input signal comprising: analog means responsive to a first control signal for adjusting said gain to provide a partially gain-corrected signal; means for converting said partially gain-corrected signal to a digital signal; digital means responsive to a second control signal for adjusting the gain of said digital signal to produce a second gain-corrected signal; and means responsive to said second gain-corrected signal for producing said first and second control signals.
Claim 2
Dependent Claim
82 words
An automatic gain control circuit for controlling the gain provided to an input signal comprising: analog means responsive to a first control signal for adjusting said gain to provide a partially gain-corrected signal; means for converting said partially gain-corrected signal to a digital signal; digital means responsive to a second control signal for adjusting the gain of said digital signal to produce a second gain-corrected signal; and means responsive to said second gain-corrected signal for producing said first and second control signals.
Claim 3
Dependent Claim
22 words
The automatic gain control circuit of claim 1 wherein said control signal producing means simultaneously produces said first and second control signals.
Claim 4
Dependent Claim
56 words
The automatic gain control circuit of claim 1 wherein said means responsive to said second gain-corrected signal generates a quotient utilizing a divisor which is a constant related to exponential gain and wherein the integer portion of such quotient provides said first control signal while the remainder portion is used to generate said second control signal.
Claim 5
Dependent Claim
29 words
The automatic gain control circuit of claim 1 wherein said analog means comprises a plurality of stages of analog gain increments selectable in response to said first control signal.
Claim 6
Dependent Claim
41 words
The automatic gain control circuit of claim 1 or 4 wherein said digital means comprises means for multiplying said partially gain-corrected signal by said second control signal and wherein said second control signal represents a gain variable over a continuous range.
Claim 7
Dependent Claim
16 words
The automatic gain control circuit of claim 5 wherein the said gains are linear in decibels.
Claim 8
Dependent Claim
47 words
The automatic gain control circuit of claim 1 wherein said control signal producing means includes: means for generating an error signal from said second gain-corrected signal, and means receiving as an input said error signal for generating from said error signal said first and second control signals.
Claim 9
Dependent Claim
40 words
The automatic gain control circuit of claim 7 wherein said error signal generating means comprises: means for squaring said second gain corrected signal; and means for comparing said second gain-corrected signal to a reference signal to produce said error signal.
Claim 10
Dependent Claim
42 words
The automatic gain control circuit of claim 7 wherein said error signal generating means comprises: means for deriving or approximating the difference between the mean-square value of said second gain-corrected signal and a suitably selected reference signal to produce said error signal.
Claim 11
Dependent Claim
87 words
The automatic gain control circuit of claim 7 wherein said receiving means comprises: means for summing said error signal with a present gain exponent to produce a dividend; means for dividing said dividend by a constant related to a gain increment in decibels; means for determining the integer portion of said quotient and the remainder portion of said quotient; means for determining said first control signal from said integer portion; and means for determining said present gain exponent and said second control signal from said remainder portion.
Claim 12
Dependent Claim
153 words
An automatic gain control circuit for adjusting the gain of an input signal to a desired value comprising: a plurality of stages of analog gain, each stage providing an increment of decibel gain and being selectably insertable into the path of said input signal to provide its associated gain to said input signal to produce a coarsely corrected signal in response to a digital control signal; means for converting said coarsely corrected signal into a digital signal; means for multiplying said digital signal by a digital number selectably variable to represent a gain continuously variable over a range to provide an output signal representing a fine gain adjustment of said coarsely corrected signal; and means responsive to the deviation of said output signal from said desired value for generating said digital control signal and digital number in such a manner that said output signal converges to the value of said desired output signal.
Claim 13
Dependent Claim
153 words
An automatic gain control circuit for adjusting the gain of an input signal to a desired value comprising: a plurality of stages of analog gain, each stage providing an increment of decibel gain and being selectably insertable into the path of said input signal to provide its associated gain to said input signal to produce a coarsely corrected signal in response to a digital control signal; means for converting said coarsely corrected signal into a digital signal; means for multiplying said digital signal by a digital number selectably variable to represent a gain continuously variable over a range to provide an output signal representing a fine gain adjustment of said coarsely corrected signal; and means responsive to the deviation of said output signal from said desired value for generating said digital control signal and digital number in such a manner that said output signal converges to the value of said desired output signal.
References Cited (Backward Citations)
US3931584A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-07-15 | 1984-01-14 | 1984-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-15 | 1988-01-14 | 1988-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-15 | 1992-01-14 | 1992-07-15 | $7700.00 | Window Closed / Lapsed |