US6147555A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplification system having mask detection
Assignee: Intel Corp
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Filing: 1998-10-19
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Granted: 2000-11-14
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Expires: 2018-10-19
Abstract
Abstract A method and apparatus reduce the out-of-band frequency components of an RF amplified signal, preferably a CDMA signal, which has a carrier frequency which is not known in advance. The apparatus and method feature locating the frequency of the incoming signal by examining an RF output signal having both in-band frequency components and out-of-band frequency components. Typically the output signal is generated using a high-power, Class A/B amplifier. Once the frequency of the carrier has been determined, the out-of-band components are used to generate control signals which, in, for example, a feedback or feedforward circuitry, reduce the energy of the out-of-band signals and thereby provide a more linear amplifier transfer function.
Inventors
- 👤 Richard D. Posner
- 👤 Kwang Kim
- 👤 Stefan Klein
- 👤 Wayne Roberts
- 👤 Gregory French
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:49
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/32; H03F1/3241; H03F1/3223; H03F1/3229
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
121 words
Apparatus for reducing out-of-band frequency components of an RF signal having a carrier frequency which is not known in advance, and having both in-band frequency components and the out-of band frequency components, such apparatus comprising: a network for amplifying an input signal for producing said RF signal, said network having adjustable electrical characteristics; and a control system connected to the network for locating a frequency within the bandwidth of the amplified RF signal and for detecting energy in the out-of band frequency components for producing a control signal related to the energy in the out-of-band frequency components, such control signal being coupled to the network to adjust the electrical characteristics of the network and reduce the energy in the out-of-band frequencies.
Claim 2
Dependent Claim
121 words
Apparatus for reducing out-of-band frequency components of an RF signal having a carrier frequency which is not known in advance, and having both in-band frequency components and the out-of band frequency components, such apparatus comprising: a network for amplifying an input signal for producing said RF signal, said network having adjustable electrical characteristics; and a control system connected to the network for locating a frequency within the bandwidth of the amplified RF signal and for detecting energy in the out-of band frequency components for producing a control signal related to the energy in the out-of-band frequency components, such control signal being coupled to the network to adjust the electrical characteristics of the network and reduce the energy in the out-of-band frequencies.
Claim 3
Dependent Claim
19 words
The apparatus of claim 1, wherein the network comprises a predistorter having adjustable characteristics controlled by the control signal.
Claim 4
Dependent Claim
19 words
The apparatus of claim 1, wherein the network comprises an amplifier having adjustable characteristics controlled by the control signal.
Claim 5
Dependent Claim
19 words
The apparatus of claim 3, wherein at least one adjustable characteristic comprises a bias point parameter of the amplifier.
Claim 6
Dependent Claim
12 words
The apparatus of claim 1, wherein the network comprises a feedforward network.
Claim 7
Dependent Claim
12 words
The apparatus of claim 1, wherein the signal comprises a CDMA signal.
Claim 8
Dependent Claim
26 words
The apparatus of claim 1, further comprising a second network having adjustable characteristics, the characteristics of the second network also being controlled by the control system.
Claim 9
Dependent Claim
14 words
The apparatus of claim 1, wherein the control system comprises a digital signal processor.
Claim 10
Independent Claim
74 words
A method of reducing out-of-band-frequency components introduced into an RF signal having in-band frequency components, having a carrier frequency not known in advance, by a signal processing network with adjustable electrical characteristics, the method comprising: locating an in-band frequency component of the RF signal; detecting energy at frequencies at a predetermined offset from the located in-band frequency component; and adjusting network electrical characteristics based on said detected energy to reduce the out-of-band frequency energy.
Claim 11
Independent Claim
74 words
A method of reducing out-of-band-frequency components introduced into an RF signal having in-band frequency components, having a carrier frequency not known in advance, by a signal processing network with adjustable electrical characteristics, the method comprising: locating an in-band frequency component of the RF signal; detecting energy at frequencies at a predetermined offset from the located in-band frequency component; and adjusting network electrical characteristics based on said detected energy to reduce the out-of-band frequency energy.
Claim 12
Dependent Claim
49 words
The method of claim 9, wherein locating the in-band frequency component comprises: measuring the energy at a first frequency; measuring the energy at a second frequency; and determining whether the energy measured at the second frequency exceeds the energy measured at the first frequency by more than a threshold.
Claim 13
Dependent Claim
14 words
The method of claim 9, further comprising heterodyning the signal having out-of-band frequency energy.
Claim 14
Dependent Claim
182 words
Apparatus for reducing distortion components introduced into an input signal by passing such signal through an amplifier operating with a non-linear output signal versus input signal transfer characteristic, such signal having a bandwidth centered about a carrier frequency not known in advance, such distortion components being at frequencies outside the bandwidth, the apparatus comprising: (A) a predistorter, connected to receive the input signal and having an output coupled to the amplifier, such predistorter having a predistorter non-linear output signal versus input signal transfer characteristic selectably adjustable in accordance with an out-of-band feedback control signal to provide a substantially linear amplifier output power versus input signal power transfer characteristic; and (B) a feedback loop comprising a control system connected to the amplifier output for locating the carrier frequency of the input signal and for producing a feedback control signal related to energy in the distortion frequency components outside the bandwidth of the amplified input signal, such feedback control signal being coupled to the predistorter for adjusting characteristics of the predistorter to reduce the energy in the out-of-band frequency components of the amplifier output.
Claim 15
Dependent Claim
182 words
Apparatus for reducing distortion components introduced into an input signal by passing such signal through an amplifier operating with a non-linear output signal versus input signal transfer characteristic, such signal having a bandwidth centered about a carrier frequency not known in advance, such distortion components being at frequencies outside the bandwidth, the apparatus comprising: (A) a predistorter, connected to receive the input signal and having an output coupled to the amplifier, such predistorter having a predistorter non-linear output signal versus input signal transfer characteristic selectably adjustable in accordance with an out-of-band feedback control signal to provide a substantially linear amplifier output power versus input signal power transfer characteristic; and (B) a feedback loop comprising a control system connected to the amplifier output for locating the carrier frequency of the input signal and for producing a feedback control signal related to energy in the distortion frequency components outside the bandwidth of the amplified input signal, such feedback control signal being coupled to the predistorter for adjusting characteristics of the predistorter to reduce the energy in the out-of-band frequency components of the amplifier output.
References Cited (Backward Citations)
US5455538A
Cited
US5570063A
Cited
WO1997008822A1
Cited
US5712593A
Cited
WO1998004034A1
Cited
US5929704A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-11-14 | 2004-05-15 | 2004-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-11-14 | 2008-05-15 | 2008-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-11-14 | 2012-05-15 | 2012-11-14 | $7700.00 | Window Closed / Lapsed |