US6204731B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power amplifier
Assignee: Wipro Ltd
•
Filing: 1999-04-30
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Granted: 2001-03-20
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Expires: 2019-04-30
Abstract
Abstract A power amplifier has an input terminal for receiving a signal to be amplified and an output terminal to which the amplified signal is passed, and comprises single stage which-, or a plurality of cascaded amplifier stages one of, which-, is formed from a plurality of amplifiers connected in parallel with their input ports interconnected and their output ports interconnected. Said one stage may be the last stage. In one arrangement said one stage comprises two or more amplifiers at least one of which is biased at class AB and at least another of which is biased at class C. Alternatively said one stage comprises two or more amplifiers at least one of which is biased at class AB and at least another of which may be switchably biased at class AB or class C.Again, alternatively, the said one stage may comprise two or more amplifiers, each of which may be switchably biased at class AB or class C and the gates widths of which may be different. The amplifier stages may comprise bipolar junction transistors or field effect transistors. Means are preferably provided enabling the power to be divided to the input to each amplifier in said one stage and means enabling the outputs of each of said amplifiers to be combined. There may be provided between the power dividing point to the input of each of said amplifiers a matching circuit enabling phase shifting to compensate for the amplitude and phase response of each of said amplifiers. In said one stage there may be provided between the output ports of each of said amplifiers and the combining point a matching circuit enabling phase shifting to compensate for the amplitude and phase response of each of said amplifiers.
Inventors
- 👤 Cao Jiang
- 👤 Wang Xinwei
- 👤 Hiroshi Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:08
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/20; H03F3/21; H03F3/211; H03F1/00; H03F1/02; H03F1/0205; H03F1/0277; H03F3/217; H03F3/2171; H03F2200/00; H03F2200/408; H03F2200/516; H03F2203/00; H03F2203/72; H03F2203/7236
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
126 words
A power amplifier having an input terminal for receiving an input signal to be amplified and an output terminal to which the amplified signal is passed, the power amplifier comprising a plurality of cascaded amplifier stages one of which comprises a plurality of amplifiers connected in parallel with their input ports interconnected and their output ports interconnected; and said plurality of amplifiers connected in parallel defining at least a class AB amplifier and a class C amplifier, wherein if the power level of the input signal is below a predetermined input signal, then the class AB amplifier alone is operational and if the power level of the input signal transitions above the predetermined input signal, then both the class AB and class C amplifiers are operational.
Claim 2
Dependent Claim
126 words
A power amplifier having an input terminal for receiving an input signal to be amplified and an output terminal to which the amplified signal is passed, the power amplifier comprising a plurality of cascaded amplifier stages one of which comprises a plurality of amplifiers connected in parallel with their input ports interconnected and their output ports interconnected; and said plurality of amplifiers connected in parallel defining at least a class AB amplifier and a class C amplifier, wherein if the power level of the input signal is below a predetermined input signal, then the class AB amplifier alone is operational and if the power level of the input signal transitions above the predetermined input signal, then both the class AB and class C amplifiers are operational.
Claim 3
Dependent Claim
23 words
An amplifier as claimed in claim 1 , wherein said one stage is the last stage in said plurality of cascaded amplifier stages.
Claim 4
Dependent Claim
43 words
An amplifier as claimed in claim 1 , wherein said one stage comprises two or more amplifiers at least one of which is biased at class AB and at least another of which may be switchably biased at class AB or class C.
Claim 5
Dependent Claim
45 words
An amplifier as claimed in claim 3 , arranged such that the amplifier with switchable bias is biased at class C when the power level of the input signal is low, and at class AB when the power level of the input signal is high.
Claim 6
Dependent Claim
39 words
An amplifier as claimed in claim 1 , wherein said one stage comprises two or more amplifiers each of which may be switchably biased at class AB or class C and the gates of widths of which are different.
Claim 7
Dependent Claim
82 words
An amplifier as claimed in claim 5 arranged such that the FET with a smaller gate width is biased at class AB and the other at class C when the input power is low, but the amplifier who's FET with a larger gate width is biased at class AB and the others are biased at class C when the input power level is medium and in which all the amplifiers are biased to class AB when the input power level is HIGH.
Claim 8
Dependent Claim
29 words
An amplifier as claimed in claim 2 , wherein the amplifiers in said one stage comprise different threshold voltage biased field effect transistors having the same gate bias voltages.
Claim 9
Dependent Claim
18 words
An amplifier as claimed in claim 1 , wherein said amplifier stages are formed of bipolar junction transistors.
Claim 10
Dependent Claim
18 words
An amplifier as claimed in claim 1 , wherein said amplifier stages are formed of field effect transistors.
Claim 11
Dependent Claim
25 words
An amplifier as claimed in claim 1 including means enabling the power to be divided to the input to each amplifier in said one stage.
Claim 12
Dependent Claim
20 words
An amplifier as claimed in claim 1 including means enabling the outputs of each of said amplifiers to be combined.
Claim 13
Dependent Claim
44 words
An amplifier as claimed in claim 1 wherein there is provided between the power dividing point to the input of each of said amplifiers and matching circuit means enabling phase shifting to compensate for the amplitude a phase response of each of said amplifiers.
Claim 14
Dependent Claim
48 words
An amplifier as claimed in claim 1 wherein in said final stage there is provided between the output port of each of said amplifiers and the combining point a matching circuit means enabling phase shifting to compensate for the amplitude and phase response of each of said amplifiers.
Claim 15
Dependent Claim
95 words
A power amplifier having an input terminal for receiving a signal to be amplified and an output terminal to which the amplified signal is passed, and which comprises a plurality of amplifiers connected in parallel with their input ports interconnected and their output ports interconnected; wherein said plurality of amplifiers connected in parallel includes a first amplifier and a second amplifier; and wherein the first amplifier alone is operational when the input signal is below a predetermined level, and both the first and second amplifiers are operational when the signal is above the predetermined level.
Claim 16
Dependent Claim
95 words
A power amplifier having an input terminal for receiving a signal to be amplified and an output terminal to which the amplified signal is passed, and which comprises a plurality of amplifiers connected in parallel with their input ports interconnected and their output ports interconnected; wherein said plurality of amplifiers connected in parallel includes a first amplifier and a second amplifier; and wherein the first amplifier alone is operational when the input signal is below a predetermined level, and both the first and second amplifiers are operational when the signal is above the predetermined level.
Claim 17
Dependent Claim
37 words
An amplifier as claimed in claim 14 , wherein there are provided two or more amplifiers at least one of which is biased at class AB and at least another of which is biased at class C.
Claim 18
Dependent Claim
49 words
An amplifier as claimed in claim 15 , arranged such that when the power level of the input signal is low the class AB amplifier alone is operational and when the power level of the input signal becomes high both the class AB and class C amplifiers are operational.
Claim 19
Dependent Claim
42 words
An amplifier as claimed in claim 14 , wherein there are provided two or more amplifiers at least one of which is biased at class AB and at least another of which may be switchably biased at class AB or class C.
Claim 20
Dependent Claim
45 words
An amplifier as claimed in claim 17 , arranged such that the amplifier with switchable bias is biased at class C when the power level of the input signal is low, and at class AB when the power level of the input signal is high.
Claim 21
Dependent Claim
37 words
An amplifier as claimed in claim 14 , wherein there are provided two or more amplifiers each of which may be switchably biased at class AB or class C and the gates widths of which are different.
Claim 22
Dependent Claim
81 words
An amplifier as claimed in claim 19 arranged such that the FET with a smaller gate width is biased at class AB and the other at class C when the input power is low, but the amplifier who's FET with a wider gate is biased at class AB and the others are biased at class C when the input power level is medium and in which all the amplifiers are biased to class AB when the input power level is HIGH.
Claim 23
Dependent Claim
24 words
An amplifier as claimed in claim 14 , wherein the amplifiers comprise different threshold voltage field effect transistors having the same gate bias voltages.
Claim 24
Dependent Claim
17 words
A power amplifier as claimed in claim 14 wherein said amplifiers are formed of bipolar junction transistors.
Claim 25
Dependent Claim
15 words
An amplifier as claimed in claim 14 , wherein said amplifiers are formed of FETs.
Claim 26
Dependent Claim
35 words
An amplifier as claimed in claim 14 , including means enabling the power to be divided to the input to each amplifier and means enabling the outputs of each of said amplifiers to be combined.
Claim 27
Dependent Claim
45 words
An amplifier as claimed in claim 14 , wherein there is provided between the power dividing point to the input of each of said amplifiers and matching circuit means enabling phase shifting to compensate for the amplitude and phase response of each of said amplifiers.
Claim 28
Dependent Claim
44 words
An amplifier as claimed in claim 14 , wherein there is provided between the output ports of each of said amplifiers and the combining point a matching circuit enabling phase shifting to compensate for the amplitude and phase response of each of said amplifiers.
Claim 29
Dependent Claim
21 words
An amplifier according to claim 14 , wherein the first amplifier is class AB and the second amplifier is class C.
Claim 30
Independent Claim
95 words
A method for amplifying a signal comprising the steps of: biasing a first amplifier at a predetermined level; biasing a second amplifier at a level that is different from the predetermined level of the first amplifier; coupling the first and second amplifiers in parallel; and applying an input signal to the first and second amplifiers coupled in parallel, wherein the first amplifier alone is substantially operational when the input signal is below a predetermined level and the first and the second amplifiers are both substantially operational when the input signal is above the predetermined level.
Claim 31
Independent Claim
95 words
A method for amplifying a signal comprising the steps of: biasing a first amplifier at a predetermined level; biasing a second amplifier at a level that is different from the predetermined level of the first amplifier; coupling the first and second amplifiers in parallel; and applying an input signal to the first and second amplifiers coupled in parallel, wherein the first amplifier alone is substantially operational when the input signal is below a predetermined level and the first and the second amplifiers are both substantially operational when the input signal is above the predetermined level.
Claim 32
Dependent Claim
16 words
A method according to claim 27 , wherein the first amplifier is a class AB amplifier.
Claim 33
Dependent Claim
16 words
A method according to claim 27 ; wherein the second amplifier is a class C amplifier.
Claim 34
Dependent Claim
26 words
A method according to claim 27 , wherein the gate voltage for the first amplifier is set to a value higher than its pinch off voltage.
Claim 35
Dependent Claim
25 words
A method according to claim 27 , wherein the gate voltage for the second amplifier is set to a value lower than its pinch-off voltage.
References Cited (Backward Citations)
US5420541A
Cited
US5548246A
Cited
US5635870A
Cited
US5949287A
Cited
US6091966A
Cited
US5977834A
Cited
US6128478A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-19 | 2004-09-18 | 2005-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-19 | 2008-09-18 | 2009-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-19 | 2012-09-18 | 2013-03-20 | $7700.00 | Window Closed / Lapsed |