US5136257A
Expired / Lapsed
US
⏱️ 0.0 years remaining
RF amplifier bias circuit
Assignee: Agilent Technologies Inc
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Filing: 1989-12-07
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Granted: 1992-08-04
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Expires: 2009-12-07
Abstract
Abstract An amplifier circuit includes an amplifier and a biasing circuit. A control circuit generates an amplifier output level control voltage which is coupled to the biasing circuit for controlling the operating point of the amplifier in response to the level of control voltage.
Inventors
- 👤 Ian Reading
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:16
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3036
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
165 words
An amplifier circuit for generating an output voltage comprising: an amplifier having an input and an output; a biasing circuit for and coupled to said amplifier; control means for generating an amplifier output power level control voltage; means for comparing a signal indicative of said amplifier output power level with said output power level control voltage, generating a difference signal indicative of the difference between said signal indicative of said output power level and said output power level control voltage, and controlling the input power level of said amplifier on the basis of at least said difference signal; and means for coupling said control means to said biasing circuit in an open loop manner for dynamically controlling the operating point of said amplifier in response to the power level control voltage such that current and voltage parameters defining said operating point vary in opposite sense to one another in coordination with change in amplifier output power level, so as to control distortion and power dissipation.
Claim 2
Dependent Claim
165 words
An amplifier circuit for generating an output voltage comprising: an amplifier having an input and an output; a biasing circuit for and coupled to said amplifier; control means for generating an amplifier output power level control voltage; means for comparing a signal indicative of said amplifier output power level with said output power level control voltage, generating a difference signal indicative of the difference between said signal indicative of said output power level and said output power level control voltage, and controlling the input power level of said amplifier on the basis of at least said difference signal; and means for coupling said control means to said biasing circuit in an open loop manner for dynamically controlling the operating point of said amplifier in response to the power level control voltage such that current and voltage parameters defining said operating point vary in opposite sense to one another in coordination with change in amplifier output power level, so as to control distortion and power dissipation.
Claim 3
Dependent Claim
13 words
The amplifier circuit of claim 1 wherein said biasing circuit comprises another amplifier.
Claim 4
Dependent Claim
13 words
The amplifier circuit of claim 1 wherein said amplifier comprises an RF amplifier.
Claim 5
Dependent Claim
24 words
The amplifier circuit of claim 1 wherein said control means comprises a microprocessor control circuit comprising a microprocessor and a digital to analog converter.
Claim 6
Independent Claim
173 words
A method of operating an amplifier circuit comprising an amplifier and a biasing circuit for said amplifier, said method comprising the following steps: operating said amplifier so as to produce an output signal; generating an amplifier output power level control voltage; applying said output power level control voltage to said biasing circuit in an open loop manner; comparing a signal indicative of the amplifier output power level with said output power level control voltage, generating a difference signal indicative of the difference between said signal indicative of said output power level and said output power level control voltage, and controlling the input power level of said amplifier on the basis of at least said difference signal; and dynamically controlling the operating bias point of said amplifier with said biasing circuit in response to said output power level control voltage such that current and voltage parameters defining said operating point vary in opposite sense to one another in coordination with change in amplifier output power level, so as to control distortion and power dissipation.
Claim 7
Independent Claim
173 words
A method of operating an amplifier circuit comprising an amplifier and a biasing circuit for said amplifier, said method comprising the following steps: operating said amplifier so as to produce an output signal; generating an amplifier output power level control voltage; applying said output power level control voltage to said biasing circuit in an open loop manner; comparing a signal indicative of the amplifier output power level with said output power level control voltage, generating a difference signal indicative of the difference between said signal indicative of said output power level and said output power level control voltage, and controlling the input power level of said amplifier on the basis of at least said difference signal; and dynamically controlling the operating bias point of said amplifier with said biasing circuit in response to said output power level control voltage such that current and voltage parameters defining said operating point vary in opposite sense to one another in coordination with change in amplifier output power level, so as to control distortion and power dissipation.
Claim 8
Dependent Claim
33 words
The method of claim 5 wherein said amplifier means comprises a plurality of cascaded amplifiers and further comprising the step of dynamically controlling the respective operating points of said plurality of cascaded amplifiers.
Claim 9
Independent Claim
126 words
A system comprising: amplifier having an input and an output; control means for generating an amplifier output level control voltage; comparison means coupled to said amplifier and said control means for generating an error signal representing the difference between said output and said level control voltage; modulating means coupled to said amplifier and said comparison means for modulating the input to said amplifier with said error signal; and bias means coupled to said amplifier means and said control means as part of an open loop for varying the operating bias point of the amplifier in response to said level control voltage such that current and voltage parameters defining said operating point vary in opposite sense to one another, so as to control distortion and power dissipation.
Claim 10
Independent Claim
126 words
A system comprising: amplifier having an input and an output; control means for generating an amplifier output level control voltage; comparison means coupled to said amplifier and said control means for generating an error signal representing the difference between said output and said level control voltage; modulating means coupled to said amplifier and said comparison means for modulating the input to said amplifier with said error signal; and bias means coupled to said amplifier means and said control means as part of an open loop for varying the operating bias point of the amplifier in response to said level control voltage such that current and voltage parameters defining said operating point vary in opposite sense to one another, so as to control distortion and power dissipation.
Claim 11
Dependent Claim
20 words
The system of claim 7 wherein said amplifier means comprises a plurality of cascaded amplifiers coupled to said bias means.
Claim 12
Dependent Claim
13 words
The system of claim 7 wherein said amplifier means comprises an RF amplifier.
Claim 13
Dependent Claim
23 words
The system of claim 7 wherein said control means comprises a microprocessor control circuit comprising a microprocessor and a digital to analog converter.
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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) | 1995-08-04 | 1996-02-03 | 1996-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-04 | 2000-02-03 | 2000-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-04 | 2004-02-03 | 2004-08-04 | $7700.00 | Window Closed / Lapsed |