US6313703B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of antiphase signals for predistortion training within an amplifier system
Assignee: MaxLinear Asia Singapore Pte Ltd
•
Filing: 2000-03-02
•
Granted: 2001-11-06
•
Expires: 2020-03-02
Abstract
Abstract A LINC amplifier of a radio frequency transmitter provides substantially linear amplification from two nonlinear amplifiers by decomposing the original signal into two constant amplitude envelope, phase varying signals, which, when combined, constructively and destructively interfere to re-form the original signal. The output of the LINC amplifier, which is to be transmitted via an antenna, is an amplified form of the original signal. The LINC amplifier uses a digital control mechanism to control and adapt a digital compensation network that directly compensates for the imperfections of the analog RF environment, including the amplifiers. The mechanism monitors the combined amplifier output and adjusts the signal components in order to precisely compensate for any differences in the characteristics of the separate signal paths which would cause the combination not to accurately represent the original signal. The mechanism also corrects the component signals using information which can be applied to the amplifiers independent of the signal to be transmitted.
Inventors
- 👤 Andrew S. Wright
- 👤 Steven J. Bennett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:34
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/32; H03F1/3241; H03F1/3247; H03F1/02; H03F1/0205; H03F1/0294; H03F2201/00; H03F2201/32; H03F2201/3231; H03F2201/3233
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
123 words
A method of powering up an amplifier system having first and second amplification chains, wherein signal outputs of the first and second amplification chains are combined to produce an output transmission signal, the method comprising: (a) applying a first signal to the first amplification chain and a second signal to the second amplification chain, wherein the first and second signals are substantially in antiphase to inhibit emissions from an antenna; (b) adaptively predistorting the first and second signals until a desired level of balance is reached between the first and second amplification chains; (c) increasing amplification power levels of the first and second amplification chains by an incremental amount and repeating (b); and (d) repeating (c) until an operational power level is reached.
Claim 2
Independent Claim
123 words
A method of powering up an amplifier system having first and second amplification chains, wherein signal outputs of the first and second amplification chains are combined to produce an output transmission signal, the method comprising: (a) applying a first signal to the first amplification chain and a second signal to the second amplification chain, wherein the first and second signals are substantially in antiphase to inhibit emissions from an antenna; (b) adaptively predistorting the first and second signals until a desired level of balance is reached between the first and second amplification chains; (c) increasing amplification power levels of the first and second amplification chains by an incremental amount and repeating (b); and (d) repeating (c) until an operational power level is reached.
Claim 3
Dependent Claim
30 words
The method as in claim 1 , wherein the incremental amount is selected so as to maintain unwanted emissions within a predefined level during power up of the amplifier system.
Claim 4
Dependent Claim
32 words
The method as in claim 1 , further comprising performing a calibration process to determine and record amplifier control signal levels for adjusting the amplifier power levels in (c) in lock step.
Claim 5
Dependent Claim
31 words
The method of claim 1 , wherein (a) comprises varying the frequencies of the first and second signals to train the first and second amplification chains over a range of frequencies.
Claim 6
Independent Claim
119 words
A method of powering down an amplifier system having first and second amplification chains, wherein signal outputs of the first and second amplification chains are combined to produce an output transmission signal, the method comprising: (a) applying a first signal to the first amplification chain and a second signal to the second amplification chain, wherein the first and second signals are substantially in antiphase to inhibit emissions; (b) adaptively predistorting the first and second signals until a desired level of balance is reached between the first and second amplification chains; (c) decreasing amplification power levels of the first and second amplification chains by an incremental amount and repeating (b); (d) repeating (c) until a selected power level is reached.
Claim 7
Independent Claim
119 words
A method of powering down an amplifier system having first and second amplification chains, wherein signal outputs of the first and second amplification chains are combined to produce an output transmission signal, the method comprising: (a) applying a first signal to the first amplification chain and a second signal to the second amplification chain, wherein the first and second signals are substantially in antiphase to inhibit emissions; (b) adaptively predistorting the first and second signals until a desired level of balance is reached between the first and second amplification chains; (c) decreasing amplification power levels of the first and second amplification chains by an incremental amount and repeating (b); (d) repeating (c) until a selected power level is reached.
Claim 8
Dependent Claim
30 words
The method as in claim 5 , wherein the incremental amount is selected so as to maintain unwanted emissions within a predefined level during power down of the amplifier system.
Claim 9
Dependent Claim
32 words
The method as in claim 5 , further comprising performing a calibration process to determine and record amplifier control signal levels for adjusting the amplifier power levels in (c) in lock step.
Claim 10
Dependent Claim
31 words
The method of claim 5 , wherein (a) comprises varying the frequencies of the first and second signals to train the first and second amplification chains over a range of frequencies.
Claim 11
Dependent Claim
17 words
The method as in claim 5 , wherein the amplifier system is a LINC power amplifier system.
Claim 12
Independent Claim
131 words
A method of training an amplifier system having first and second amplification chains, wherein signal outputs of the first and second amplification chains are combined to produce an output transmission signal, the method comprising: (a) applying a first signal to the first amplification chain and a second signal to the second amplification chain, wherein the first and second signals fall within a first band, and are substantially in antiphase to inhibit emissions; (b) adaptively predistorting the first and second signals until a desired level of balance is reached between the first and second amplification chains; (c) increasing the bandwidth of the first and second signals and repeating (b); and (d) repeating (c) until the first and second signals have a bandwidth spanning a selected second band which encompasses the first band.
Claim 13
Independent Claim
131 words
A method of training an amplifier system having first and second amplification chains, wherein signal outputs of the first and second amplification chains are combined to produce an output transmission signal, the method comprising: (a) applying a first signal to the first amplification chain and a second signal to the second amplification chain, wherein the first and second signals fall within a first band, and are substantially in antiphase to inhibit emissions; (b) adaptively predistorting the first and second signals until a desired level of balance is reached between the first and second amplification chains; (c) increasing the bandwidth of the first and second signals and repeating (b); and (d) repeating (c) until the first and second signals have a bandwidth spanning a selected second band which encompasses the first band.
Claim 14
Dependent Claim
34 words
The method as in claim 10 , wherein the first band corresponds to a channel assigned to the amplifier system, and the second band encompasses the assigned channel and at least one adjacent channel.
Claim 15
Dependent Claim
29 words
The method as in claim 10 , wherein (c) comprises increasing the bandwidth by an increment which is sufficiently small to maintain unwanted emissions below a selected threshold level.
Claim 16
Dependent Claim
17 words
The method as in claim 10 , wherein the amplifier system is a LINC power amplifier system.
Claim 17
Independent Claim
129 words
A method of changing an operational frequency of an amplifier system having first and second amplification chains, wherein outputs of the first and second amplification chains are combined to produce an output transmission signal, the method comprising: (a) applying a first signal to the first amplification chain and a second signal to the second amplification chain, wherein the first and second signals fall within a first band, and are substantially in antiphase to inhibit emissions; (b) adaptively predistorting the first and second signals until a desired level of balance is reached between the first and second amplification chains; (c) shifting the band of the first and second signals while maintaining said signals substantially in antiphase, and repeating (b); and (d) repeating (c) until a selected second band is reached.
Claim 18
Independent Claim
129 words
A method of changing an operational frequency of an amplifier system having first and second amplification chains, wherein outputs of the first and second amplification chains are combined to produce an output transmission signal, the method comprising: (a) applying a first signal to the first amplification chain and a second signal to the second amplification chain, wherein the first and second signals fall within a first band, and are substantially in antiphase to inhibit emissions; (b) adaptively predistorting the first and second signals until a desired level of balance is reached between the first and second amplification chains; (c) shifting the band of the first and second signals while maintaining said signals substantially in antiphase, and repeating (b); and (d) repeating (c) until a selected second band is reached.
Claim 19
Dependent Claim
32 words
The method as in claim 14 , wherein the first band corresponds to a currently assigned operating frequency of the amplifier system, and the second band corresponds to a new operating frequency.
Claim 20
Dependent Claim
29 words
The method as in claim 14 , wherein (c) comprises shifting the band by an increment which is sufficiently small to maintain unwanted emissions below a selected threshold level.
Claim 21
Dependent Claim
17 words
The method as in claim 14 , wherein the amplifier system is a LINC power amplifier system.
Claim 22
Dependent Claim
111 words
A transmitter comprising: first and second amplification chains, each amplification chain including a digital compensation signal processor circuit which predistorts a respective signal passed therealong; an adaptive control processor which adaptively adjusts the digital compensation signal processor circuits to balance the first and second amplification chains; a combiner circuit coupled to outputs of the first and second amplification chains such that signals amplified along the first and second amplification chains are combined for transmission; and a signal generator circuit that applies training signals to the first and second amplification chains to train the digital compensation signal processor circuits during non-transmission events, wherein the training signals are in antiphase to inhibiting emissions.
Claim 23
Dependent Claim
111 words
A transmitter comprising: first and second amplification chains, each amplification chain including a digital compensation signal processor circuit which predistorts a respective signal passed therealong; an adaptive control processor which adaptively adjusts the digital compensation signal processor circuits to balance the first and second amplification chains; a combiner circuit coupled to outputs of the first and second amplification chains such that signals amplified along the first and second amplification chains are combined for transmission; and a signal generator circuit that applies training signals to the first and second amplification chains to train the digital compensation signal processor circuits during non-transmission events, wherein the training signals are in antiphase to inhibiting emissions.
Claim 24
Dependent Claim
57 words
The transmitter as in claim 18 , further comprising a control circuit that ramps up power levels of the first and second amplification chains, during application of the antiphase training signals thereto, while monitoring a level of balance between the amplification chains, to thereby power up the amplification chains while maintaining emissions below a selected threshold level.
Claim 25
Dependent Claim
31 words
The transmitter as in claim 19 , wherein the control circuit ramps up the power levels in steps that are selected so as to maintain unwanted emissions below the threshold level.
Claim 26
Dependent Claim
57 words
The transmitter as in claim 18 , further comprising a control circuit that ramps down power levels of the first and second amplification chains, during application of the antiphase training signals thereto, while monitoring a level of balance between the amplification chains, to thereby power down the amplification chains while maintaining emissions below a selected threshold level.
Claim 27
Dependent Claim
30 words
The transmitter as in claim 21 , wherein the control circuit ramps down the power levels in steps that are selected so as to maintain emissions below the threshold level.
Claim 28
Dependent Claim
46 words
The transmitter of claim 18 , wherein the signal generator circuit increases a bandwidth of the antiphase training signals over time from a first band to a second band that encompasses the first band to provide narrow-to-wide band training of the digital compensation signal processor circuits.
Claim 29
Dependent Claim
35 words
The transmitter of claim 23 , wherein the signal generator circuit increases the bandwidth of the antiphase training signals by incremental amounts that are selected so as to maintain emissions below a selected threshold level.
Claim 30
Dependent Claim
30 words
The transmitter as in claim 18 , wherein the signal generator circuit shifts a band of the antiphase training signals over time to change an operating frequency of the transmitter.
Claim 31
Dependent Claim
38 words
The transmitter as in claim 25 , wherein the signal generator circuit shifts the band of the antiphase training signals over time by incremental amounts that are selected so as to maintain emissions below a selected threshold level.
Claim 32
Dependent Claim
35 words
The transmitter as in claim 18 , wherein the signal generator circuit varies the frequencies of the antiphase training signals over time to train the first and second amplification chains over a range of frequencies.
Claim 33
Dependent Claim
45 words
The transmitter as in claim 18 , further comprising a signal component separator which divides an input transmission signal into first and second component signals having substantially constant amplitudes and varying phases, and which applies the component signals to the first and second amplification chains.
References Cited (Backward Citations)
US3777275A
Cited
US3908401A
Cited
US3978424A
Cited
US3896395A
Cited
US3909742A
Cited
US3927379A
Cited
US4068186A
Cited
US4090147A
Cited
US4319204A
Cited
US4178557A
Cited
US4420723A
Cited
US4346354A
Cited
US4433312A
Cited
US4490684A
Cited
US4540957A
Cited
US4584541A
Cited
US4656434A
Cited
US4835493A
Cited
US5107520A
Cited
US5148448A
Cited
EP0441110B1
Cited
US5287069A
Cited
EP0466123B1
Cited
US5264807A
Cited
US5093636A
Cited
US5249201A
Cited
US5659272A
Cited
EP0529874B1
Cited
US5469127A
Cited
US5329259A
Cited
US5410280A
Cited
US5365187A
Cited
US5631604A
Cited
US5574967A
Cited
US5568088A
Cited
US5638024A
Cited
US5675288A
Cited
US5568086A
Cited
US5748678A
Cited
US5732333A
Cited
US5760646A
Cited
US5705959A
Cited
US5892395A
Cited
US5867065A
Cited
US5886573A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-11-05 | 2005-05-07 | 2005-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-11-05 | 2009-05-07 | 2009-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-11-05 | 2013-05-07 | 2013-11-06 | $7700.00 | Window Closed / Lapsed |