Patent US4270222A successfully refreshed from Google Patents.
US4270222A
Expired / Lapsed
US
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Radio-frequency head having a self-adaptive dynamic range
Assignee: Thales SA
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Filing: 1980-03-17
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Granted: 1981-05-26
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Expires: 2000-03-17
Abstract
Abstract An HF receiver head having high sensitivity and capable of receiving variable-level input signals has characteristics which are adjusted as a function of the received signal level. The HF head essentially comprises a generator for delivering control voltages as a function of the amplitude of the received signals. The dynamic range of the input amplifier and of the mixer can thus be varied as a function of the received signal level up to a predetermined threshold value. Above this threshold value, an input attenuator assumes increasing values which makes it possible to attain a wide dynamic range of the HF head under optimum conditions of sensitivity and linearity.
Inventors
- 👤 Christophe Menant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:02
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3052
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
194 words
An HF head having one input and one output and comprising: a stage for converting received signals in which provision is made for a local oscillation generator and a mixer and which stage has one signal input, one output and one input for controlling the level of local oscillation; a variable attenuator having one signal input coupled to the input of the HF head, one output coupled to the signal input of the converter stage, and one input for controlling its attenuation coefficient; means having one input and one output for detecting the level of signals received; control means having one input coupled to the output of the detection means and at least one first output for delivering a first control signal, and one second output for delivering a second control signal, said first and second outputs being coupled respectively to the control inputs of the converter stage and of the attenuator in order to ensure that the level of the local oscillation current and the coefficient of attenuation of the attenuator between predetermined limiting values of the received signal level are of successively increasing value as a function of increasing received signal level.
Claim 2
Dependent Claim
194 words
An HF head having one input and one output and comprising: a stage for converting received signals in which provision is made for a local oscillation generator and a mixer and which stage has one signal input, one output and one input for controlling the level of local oscillation; a variable attenuator having one signal input coupled to the input of the HF head, one output coupled to the signal input of the converter stage, and one input for controlling its attenuation coefficient; means having one input and one output for detecting the level of signals received; control means having one input coupled to the output of the detection means and at least one first output for delivering a first control signal, and one second output for delivering a second control signal, said first and second outputs being coupled respectively to the control inputs of the converter stage and of the attenuator in order to ensure that the level of the local oscillation current and the coefficient of attenuation of the attenuator between predetermined limiting values of the received signal level are of successively increasing value as a function of increasing received signal level.
Claim 3
Dependent Claim
59 words
An HF head according to claim 1, wherein the output of the attenuator is coupled to the input of the converter stage via an amplifying stage having one input for controlling the dynamic range of the signal applied thereto, the control means being provided in addition with a third output coupled to the control input of said amplifying stage.
Claim 4
Dependent Claim
43 words
An HF head according to claim 1 or claim 2, wherein the input of the detection means is connected to any one of the points of said HF head between the signal input of the attenuator and the output of the converter stage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-25 | 1984-11-24 | 1985-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-25 | 1988-11-24 | 1989-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-25 | 1992-11-24 | 1993-05-26 | $7700.00 | Window Closed / Lapsed |