Patent US5912588A successfully refreshed from Google Patents.
US5912588A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gain control circuit for a linear power amplifier
Assignee: Nokia Technologies Oy
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Filing: 1997-07-01
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Granted: 1999-06-15
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Expires: 2017-07-01
Abstract
Abstract The invention relates to the gain control of radio amplifiers. In an amplifier circuit according to the invention, the employed output level is a differential pair provided with a tanh -1 predistorter as a control device. The predistortion is adjusted so that the differential pair operates all the time in the linear region, when the bias current I E and the transconductance of the pair are changed. By using the amplifier circuit according to the invention, there is achieved linear operation within a wide range of output power.
Inventors
- 👤 Kari Nummila
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:10
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3036; H03F; H03F1/00; H03F1/32; H03F1/3241
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
70 words
An amplifier system, characterized in that the amplifier system comprises an amplifier stage with a certain operation curve, and a predistorter that has an inverted operation curve, in relation to said amplifier stage, in order to linearize the operation curve of the amplifier system; and that said predistorter also is arranged to control the amplification of the amplifier system, further characterized in that said amplifier stage is a differential pair.
Claim 2
Dependent Claim
70 words
An amplifier system, characterized in that the amplifier system comprises an amplifier stage with a certain operation curve, and a predistorter that has an inverted operation curve, in relation to said amplifier stage, in order to linearize the operation curve of the amplifier system; and that said predistorter also is arranged to control the amplification of the amplifier system, further characterized in that said amplifier stage is a differential pair.
Claim 3
Dependent Claim
70 words
An amplifier system, characterized in that the amplifier system comprises an amplifier stage with a certain operation curve, and a predistorter that has an inverted operation curve, in relation to said amplifier stage, in order to linearize the operation curve of the amplifier system; and that said predistorter also is arranged to control the amplification of the amplifier system, further characterized in that said predistorter is a tanh -1 predistorter.
Claim 4
Dependent Claim
70 words
An amplifier system, characterized in that the amplifier system comprises an amplifier stage with a certain operation curve, and a predistorter that has an inverted operation curve, in relation to said amplifier stage, in order to linearize the operation curve of the amplifier system; and that said predistorter also is arranged to control the amplification of the amplifier system, further characterized in that said predistorter is a tanh -1 predistorter.
Claim 5
Dependent Claim
34 words
An amplifier system according to claim 1, characterized in that said amplifier stage comprises an adjustable constant current element (1) in order to adjust the bias current and operation point of said differential pair.
Claim 6
Dependent Claim
32 words
An amplifier system according to claim 2, characterized in that said predistorter comprises an adjustable constant current element (3) in order to adjust a bias current and operation point of said predistorter.
Claim 7
Dependent Claim
228 words
An amplifier system characterized in that the amplifier system comprises an amplifier stage with a certain operation curve, said amplifier stage comprising a differential pair, and a predistorter that has an inverted operation curve, in relation to said amplifier stage, in order to linearize the operation curve of the amplifier system; and that said predistorter also is arranged to control the amplification of the amplifier system, wherein said predistorter is a tanh -1 predistorter, wherein said amplifier stage comprises an adjustable constant current element (1) in order to adjust the bias current and operation point of said differential pair; wherein said predistorter comprises an adjustable constant current element (3) in order to adjust the bias current and operation point of said predistorter; and wherein, in order to control the amplification of the amplifier system and linearize the amplifier system, said constant current element (3) of the predistorter is arranged to reduce the bias current of the predistorter with those values of a control quantity (V gc ) of the constant current element with which said constant current element (1) of the differential pair is arranged to increase the bias current of the differential pair, and to increase the bias current of the predistorter with those values with which said constant current element (1) of the differential pair is arranged to reduce the bias current of the differential pair.
Claim 8
Dependent Claim
228 words
An amplifier system characterized in that the amplifier system comprises an amplifier stage with a certain operation curve, said amplifier stage comprising a differential pair, and a predistorter that has an inverted operation curve, in relation to said amplifier stage, in order to linearize the operation curve of the amplifier system; and that said predistorter also is arranged to control the amplification of the amplifier system, wherein said predistorter is a tanh -1 predistorter, wherein said amplifier stage comprises an adjustable constant current element (1) in order to adjust the bias current and operation point of said differential pair; wherein said predistorter comprises an adjustable constant current element (3) in order to adjust the bias current and operation point of said predistorter; and wherein, in order to control the amplification of the amplifier system and linearize the amplifier system, said constant current element (3) of the predistorter is arranged to reduce the bias current of the predistorter with those values of a control quantity (V gc ) of the constant current element with which said constant current element (1) of the differential pair is arranged to increase the bias current of the differential pair, and to increase the bias current of the predistorter with those values with which said constant current element (1) of the differential pair is arranged to reduce the bias current of the differential pair.
Claim 9
Dependent Claim
80 words
A radiotelephone comprising a reception part and a transmission part, said transmission part comprising: an RF amplifier system comprising an amplifier circuit having an associated operation curve, said amplifier circuit comprising a differential pair, said RF amplifier system further comprising a predistorter circuit that has an inverted operation curve, in relation to said operation curve of said amplifier circuit, for linearizing an overall operation curve of said RF amplifier system and for controlling the amplification of said RF amplifier system.
Claim 10
Dependent Claim
80 words
A radiotelephone comprising a reception part and a transmission part, said transmission part comprising: an RF amplifier system comprising an amplifier circuit having an associated operation curve, said amplifier circuit comprising a differential pair, said RF amplifier system further comprising a predistorter circuit that has an inverted operation curve, in relation to said operation curve of said amplifier circuit, for linearizing an overall operation curve of said RF amplifier system and for controlling the amplification of said RF amplifier system.
Claim 11
Dependent Claim
240 words
A radiotelephone comprising a reception part and a transmission part, said transmission part comprising: an RF amplifier system comprising an amplifier circuit having an associated operation curve, said amplifier circuit comprising a differential pair, said RF amplifier system further comprising a predistorter circuit that has an inverted operation curve in relation to said operation curve of said amplifier circuit for linearizing an overall operation curve of said RF amplifier system, wherein said predistorter circuit is coupled to said amplifier circuit and controls, at least in part, the amplification of said RF amplifier system; wherein said amplifier circuit comprises a first adjustable constant current circuit that is settable with a first input signal to adjust the bias current and operation point of said differential pair; wherein said predistorter circuit comprises a second adjustable constant current circuit that is settable with a second input signal to adjust the bias current and operation point of said predistorter circuit; and wherein, for controlling the amplification and linearization of said amplifier system, said first input signal of said first constant current circuit and said second input signal of said second constant current circuit are coupled to a same input signal such that an increase in bias current of said differential pair results in a decrease in the bias current of said predistorter circuit, while a decrease in bias current of said differential pair results in an increase in the bias current of said predistorter circuit.
Claim 12
Dependent Claim
240 words
A radiotelephone comprising a reception part and a transmission part, said transmission part comprising: an RF amplifier system comprising an amplifier circuit having an associated operation curve, said amplifier circuit comprising a differential pair, said RF amplifier system further comprising a predistorter circuit that has an inverted operation curve in relation to said operation curve of said amplifier circuit for linearizing an overall operation curve of said RF amplifier system, wherein said predistorter circuit is coupled to said amplifier circuit and controls, at least in part, the amplification of said RF amplifier system; wherein said amplifier circuit comprises a first adjustable constant current circuit that is settable with a first input signal to adjust the bias current and operation point of said differential pair; wherein said predistorter circuit comprises a second adjustable constant current circuit that is settable with a second input signal to adjust the bias current and operation point of said predistorter circuit; and wherein, for controlling the amplification and linearization of said amplifier system, said first input signal of said first constant current circuit and said second input signal of said second constant current circuit are coupled to a same input signal such that an increase in bias current of said differential pair results in a decrease in the bias current of said predistorter circuit, while a decrease in bias current of said differential pair results in an increase in the bias current of said predistorter circuit.
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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) | 2002-06-14 | 2002-12-14 | 2003-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-06-14 | 2006-12-14 | 2007-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-06-14 | 2010-12-14 | 2011-06-15 | $7700.00 | Window Closed / Lapsed |