US4479254A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Noise floor automatic gain control
Assignee: Boeing North American Inc
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Filing: 1982-12-27
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Granted: 1984-10-23
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Expires: 2002-12-27
Abstract
Abstract A noise floor automatic gain control system for radio receivers that receives a modulated signal and converts the modulated signal to a demodulated signal whose amplitude is controlled by a first gain control signal. The first gain control signal is the larger of a second automatic gain control signal that is provided by automatic gain control circuit that is activated when the demodulated signal is present, or a third automatic gain control signal that is provided by a noise floor automatic gain control circuit that is activated when the demodulated signal is not present. There is a detector circuit for detecting the presence of the demodulated signal as well as a selector circuit to select either the second automatic gain control signal or the third automatic gain control signal for the first automatic gain control signal.
Inventors
- 👤 Robert L. Craiglow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:30
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3052; H03G3/3073
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
123 words
A noise floor automatic gain control system for a radio receiver that receives a modulated signal and converts the modulated signal to a demodulated signal whose amplitude varies in response to a first automatic gain control signal controlling the gain of said radio receiver, comprising: automatic gain control means for providing a second automatic gain control signal for controlling the gain of the radio receiver when the demodulated signal is present; noise floor automatic gain control means for providing a third automatic gain control signal for controlling the gain of the radio receiver when the demodulated signal is absent; and selector means for selecting the larger of the second control signal or the third control signal as said first automatic gain control signal.
Claim 2
Dependent Claim
123 words
A noise floor automatic gain control system for a radio receiver that receives a modulated signal and converts the modulated signal to a demodulated signal whose amplitude varies in response to a first automatic gain control signal controlling the gain of said radio receiver, comprising: automatic gain control means for providing a second automatic gain control signal for controlling the gain of the radio receiver when the demodulated signal is present; noise floor automatic gain control means for providing a third automatic gain control signal for controlling the gain of the radio receiver when the demodulated signal is absent; and selector means for selecting the larger of the second control signal or the third control signal as said first automatic gain control signal.
Claim 3
Dependent Claim
34 words
The noise floor automatic gain control system according to claim 1 wherein said noise floor automatic gain control means comprises: a signal presence detector for detecting the presence or absence of the demodulated signal.
Claim 4
Dependent Claim
82 words
The noise floor automatic gain control system according to claim 1 or 2 wherein the noise floor automatic gain control means comprises: envelope detector means for detecting the envelope of the modulated signal; comparator means for comparing the envelope of the modulated signal to a first selected reference; and integrator means for integrating the output of the comparator means to provide a constant output when the demodulated signal is present and to provide a variable output when the demodulated signal is absent.
Claim 5
Independent Claim
113 words
A method of providing noise floor automatic gain control for a radio receiver that receives a modulated signal and converts the modulated signal to a demodulated signal whose amplitude varies in response to a first automatic gain control signal controlling the gain of said radio receiver, comprising the steps of: providing a second automatic gain control signal for controlling the gain of the radio receiver when the demodulated signal is present; providing a third automatic gain control signal for controlling the gain of the radio receiver when the demodulated signal is absent; and selecting the larger of the second control signal or the third control signal as said first automatic gain control signal.
Claim 6
Independent Claim
113 words
A method of providing noise floor automatic gain control for a radio receiver that receives a modulated signal and converts the modulated signal to a demodulated signal whose amplitude varies in response to a first automatic gain control signal controlling the gain of said radio receiver, comprising the steps of: providing a second automatic gain control signal for controlling the gain of the radio receiver when the demodulated signal is present; providing a third automatic gain control signal for controlling the gain of the radio receiver when the demodulated signal is absent; and selecting the larger of the second control signal or the third control signal as said first automatic gain control signal.
Claim 7
Dependent Claim
20 words
The method according to claim 4 further comprising the step of: detecting the presence or absence of the demodulated signal.
Claim 8
Dependent Claim
72 words
The method according to claim 4 or 5 wherein the step of providing a third automatic gain control signal comprises: detecting the envelope of the modulated signal; comparing the envelope of the modulated signal to a first selected reference to provide a comparison signal; and integrating the comparison signal to provide a constant output when the demodulated signal is present and to provide a variable output when the demodulated signal is absent.
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) | 1987-10-23 | 1988-04-23 | 1988-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-23 | 1992-04-23 | 1992-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-23 | 1996-04-23 | 1996-10-23 | $7700.00 | Window Closed / Lapsed |