US20060199553A1 - Integrated transceiver with envelope tracking - Google Patents
Integrated transceiver with envelope tracking Download PDFInfo
- Publication number
- US20060199553A1 US20060199553A1 US11/073,535 US7353505A US2006199553A1 US 20060199553 A1 US20060199553 A1 US 20060199553A1 US 7353505 A US7353505 A US 7353505A US 2006199553 A1 US2006199553 A1 US 2006199553A1
- Authority
- US
- United States
- Prior art keywords
- input signal
- envelope
- signal
- power supply
- input
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000012545 processing Methods 0.000 claims abstract description 40
- 230000004044 response Effects 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims description 37
- 238000001514 detection method Methods 0.000 claims description 10
- 230000009467 reduction Effects 0.000 claims description 3
- 230000001934 delay Effects 0.000 description 11
- 230000003321 amplification Effects 0.000 description 8
- 238000003199 nucleic acid amplification method Methods 0.000 description 8
- 230000008569 process Effects 0.000 description 5
- 230000006978 adaptation Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 238000012937 correction Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000000875 corresponding effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 230000001413 cellular effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/02—Transmitters
- H04B1/04—Circuits
- H04B1/0475—Circuits with means for limiting noise, interference or distortion
Definitions
- RF power amplifiers are used to provide the desired signal coverage for the particular wireless application.
- RF power amplification techniques and particularly RF power amplification techniques used for wireless applications, have inherent drawbacks to which the industry continues to direct its efforts. Specifically, in developing an RF transmission system, considerable attention is given to amplifier efficiency and signal distortion of the amplified signal.
- Amplifier efficiency which is generally defined as the level of RF power that may be achieved at the output signal compared to the power that is input into the overall amplification process, is conventionally somewhat low in wireless applications. Therefore, considerable attention within the power amplifier industry has been devoted to methods of enhancing power amplifier efficiency. Small increases in amplifier efficiency can provide significant benefits in a wireless system and reduce the overall costs necessary to run the system.
- one current technique involves the use of envelope tracking of the input signal to the amplifier and use of the detected envelope to vary the amplifier operation.
- a variable power supply is utilized for supplying power to the amplifier.
- the envelope power levels of the input signal are monitored, and the power that is supplied to the power amplifier, or typically to the final stage(s) of the power amplifier, is varied based on the monitored envelope levels. More specifically, the power that is supplied to the amplifier is varied so as to be just sufficient to reproduce the power level required by the amplifier at a given instant of time. Therefore, at low envelope power levels, a low supply voltage is provided to the amplifier, and the full supply voltage is provided to the amplifier only when the maximum power is required, that is, at the envelope peaks.
- envelope-tracking techniques improve efficiency, it is desirable to improve upon envelope tracking features. Particularly, it is desirable to improve upon and efficiently incorporate an envelope tracking power supply into a transceiver. Furthermore, it is desirable to improve upon the efficiency and linearity of an RF power amplifier, in a transceiver system. Still further, it is desirable to utilize the digital signal processing capabilities of a transceiver for implementing envelope tracking capabilities. It is further desirable to implement such features of envelope tracking while addressing imperfections or non-linearities in the tracking behavior of the power supply,
- FIG. 1 illustrates an embodiment of the present invention or an envelope-tracking power amplifier in a transceiver.
- FIG. 1A illustrates an alternative embodiment of the present invention.
- FIG. 1B illustrates another alternative embodiment of the present invention.
- FIG. 2 illustrates an alternative embodiment of the circuit of FIG. 1 utilizing predistortion of an envelope signal.
- FIG. 2A illustrates another alternative embodiment of the circuit of FIG. 1 utilizing predistortion of an envelope signal.
- the present invention addresses the above-noted drawbacks in the prior art, and specifically addresses the utilization of an envelope tracking power supply in a transceiver.
- the present invention utilizes digital signal processing within a transceiver to perform envelope extraction and provide appropriate Delay matching of the envelope and main signal paths.
- predistortion of the envelope signal is utilized to address non-linearities in the envelope tracking power supply.
- FIG. 1 illustrates one embodiment of the present invention utilized to improve the performance, efficiency and cost-effectiveness of a transceiver system.
- the overall transceiver system, or transceiver 5 includes an amplification device or amplifier 10 , such as an RF power amplifier that produces an RF output signal 14 in response to an input signal 12 .
- the input signal 12 is a digital signal that is processed by the DSP 50 , converted to analog and then appropriately upconverted to RF prior to amplification by amplifier 10 .
- the power amplifier 10 may be a single stage or multiple stage amplifier of a suitable variety for RF power amplification.
- the input signal 12 is directed along several different paths for realizing the various aspects of the invention.
- the transmit side of the transceiver 5 is illustrated.
- a receiver path is also generally part of a transceiver.
- the input signal 12 is directed along a main signal path (MSP) 16 to be amplified by amplifier 10 .
- the input signal 12 is also coupled to an envelope-tracking path 18 and is coupled to a signal processing path 20 in FIG. 1 .
- MSP 16 input signal 12 proceeds to the input of amplifier 10 , where it is amplified and produced as an output signal 14 .
- the input signal may be further processed for improving the operation of the RF power amplifier.
- a signal in the MSP 16 may be predistorted, either digitally or in an analog fashion, to address non-linearities in the power amplifier 10 , according to known predistortion principles.
- linearization techniques might also be utilized along the MSP to address non-linearities in the amplifier 10 .
- the predistortion of the input signal along the MSP 16 is disclosed in the Figures as digital predistortion and various digital predistortion techniques may be used.
- various other linearization techniques, digital or analog might be utilized along the MSP 16 for addressing amplifier non-linearities and distortion and for enhancing the performance of power amplifier 10 .
- the present invention is thus not limited to the linearity techniques or predistortion techniques of the MSP that are illustrated or specifically discussed.
- the input signal or signals 12 are shown in a digital form as quadrature I/Q signals, which, along the MSP 16 , are directed to a predistortion circuit incorporated in the DSP 50 that includes predistorter 22 and algorithm/update circuitry 28 .
- the predistorter 22 predistorts the input signal 12 , whereupon the predistorted input signal is converted to an analog signal by a D/A converter 24 and upconverted from baseband to RF by upconversion circuitry 26 .
- the RF signal is then amplified by the RF power amplifier 10 to produce analog RF output signal 14 .
- a digital predistorter 22 which may be a lookup table (LUT) circuit, for example, will generally include additional digital signal processing (DSP) circuitry 28 , which includes signal processing circuitry for implementing the digital predistortion algorithm, and any updating or adaptation of the predistortion circuit.
- DSP digital signal processing
- the LUTs of predistorter 22 may need to be adaptively populated and updated, which may be handled by the DSP 28 .
- any correction or updates to the predistortion is handled by the DSP 28 .
- the I/Q input signals 12 are directed via path 20 to the DSP 28 and are utilized to drive the predistortion process.
- the DSP 28 via path 32 , may utilize the values of the I/Q input signals to index and look up corresponding predistortion I/Q values in the respective LUTs.
- DSP 28 can also be utilized to adaptively update the values of the LUTs in predistorter 22 , or to provide additional correction algorithms through the predistorter 22 according to known digital predistortion techniques.
- a coupler 40 might be utilized to couple a portion of the analog output signal 14 to DSP 28 as a feedback signal along feedback path 42 , which includes appropriate downconversion circuitry 44 and A/D conversion circuitry 46 .
- DSP 28 utilizes the output feedback signal on path 42 to adapt the predistorter 22 based upon the knowledge of the performance of the predistortion that is provided by that feedback signal 42 .
- digital predistortion circuits 22 and the supporting DSP 28 will all be incorporated together within a larger overall DSP circuit or block indicated by reference numeral 50 in FIG. 1 . However, separate blocks or circuits might also be utilized.
- the present invention is not limited to specific layouts or positions of the DSP blocks, which handle the predistortion and/or the adaptation of the predistortion, as well as the timing alignment of the various signals of the transceiver.
- a delay element 86 (Delay 3 ) is incorporated into feedback path 42 for correlating the predistortion updating and predistortion algorithm with the input signal 12 .
- an envelope-tracking power supply 60 is utilized and is coupled to power amplifier 10 for supplying power to the amplifier via path 62 .
- the power supply 60 is operable for tracking the input signal envelope, derived from path 18 in order to vary the level of power supplied to the amplifier 10 in response to variation of the input signal envelope. More specifically, the power supplied to amplifier 10 via power supply 60 is varied so as to be sufficient to reproduce, at the amplifier output 14 , the power level required at a given instant. Therefore, at low envelope power levels, a low supply voltage is provided to amplifier 10 . A full supply voltage is only provided when maximum envelope power is required, such as at the envelope peaks of the input signal.
- the present invention utilizes envelope tracking to improve the operation of the transceiver and specifically to improve the operation and efficiency of amplifier 10 .
- the invention incorporates digital envelope detection from a digital envelope detector 70 .
- Digital envelope detector 70 may be a stand-alone function in the DSP 50 , or it may be incorporated into other digital signal processing features of the DSP of transceiver 5 .
- the present invention exploits the superior capabilities of the digital signal processing within a transceiver to perform the envelope extraction and modulation functions for the envelope tracking power supply 60 . Furthermore, the invention utilizes the digital signal processing functions of the transceiver to achieve suitable envelope tracking advantages by providing the appropriate timing and delay matching of the envelope tracking and main signal paths.
- the transceiver 5 utilizes digital signal processing block 50 to achieve peak-to-average signal reduction, such as crest factor reduction (CFR) 72 .
- the CFR 72 uses envelope detection.
- the transceiver 5 utilizes the digital envelope detection function 70 of the CFR function 72 for the purposes of incorporating an envelope-tracking PSU 60 .
- the digital envelope detection functionality 70 of the transceiver may be incorporated for various different purposes, including envelope tracking, providing an overall efficiency improvement and lower cost in the design of the DSP block 50 of the transceiver, while providing the power efficiency of envelope tracking.
- the input signal 12 is coupled from the MSP 16 onto path 18 where it is directed to digital envelope detector 70 , which is shown as part of the CFR function.
- the digital signal processing (DSP) block 50 utilizes digital envelope detector 70 to extract magnitude information of the input signal with respect to envelope detection.
- the DSP block 50 provides an envelope signal 74 to PSU 60 .
- the PSU 60 uses the envelope signal 74 to drive the PSU 60 and thereby output a signal on path 62 that meets the power requirements of power amplifier 10 .
- DSP block 50 of transceiver 5 provides precise timing control of the signals in the system by accurately matching the delays between the envelope tracking 18 and main signal paths 16 to ensure that the envelope-varying supply voltage 62 has the correct timing alignment with the input signal to the amplifier 10 .
- the present invention thus provides an efficient, cost-effective DSP implementation of timing control in a transceiver utilizing an envelope-tracking amplifier.
- the present invention eliminates such bulky and expensive components and provides a transceiver that incorporates envelope tracking capabilities and timing alignment features all in the same DSP block 50 .
- the DSP block 50 incorporates a number of delays within the main signal path 16 , the envelope-tracking path 18 and the processing paths 20 and 42 .
- the DSP block 50 ensures that PSU 60 provides appropriate power to the amplifier 10 to coincide with peaks in the envelope of the input signal 12 .
- the DSP provides proper alignment in the digital predistortion algorithm of block 28 to ensure that the proper correction is provided via predistortion from predistorter 22 for a correlated input signal 12 .
- DSP block 50 incorporates a delay element 80 referred to as Delay 1 .
- Digital-to-analog converter 82 is also utilized to convert the digitally detected envelope signal from Delay 1 into an appropriate analog signal for use by PSU 60 .
- Another delay element 84 also referred to herein as Delay 2 , is provided in the main signal path 16 .
- Delay 1 and Delay 2 are utilized to provide correlation between the peaks of the input signal 12 and the power signal 62 provided to amplifier 10 by PSU 60 . This provides sufficient power to the amplifier 10 to handle input signal peaks. While the embodiment illustrated in FIG. 1 shows two delay elements (Delay 1 , Delay 2 ), it may be suitable to utilize only one delay element.
- the inherent delay in the envelope-tracking path 18 may be significant due to the operation of the power supply and, thus, it may be suitable to eliminate Delay 1 and only utilize Delay 2 .
- Delay 2 might be eliminated and only Delay one utilized.
- Delay 1 may provide fine-tuning of timing, whereas Delay 2 may provide a coarser delay control, or vice versa.
- a Delay element 86 is incorporated into a feedback path indicated by reference numeral 42 .
- Delay component 86 is also referred to as Delay 3 .
- a Delay element 88 is incorporated into the processing path 20 , which provides a portion of the input signal to DSP block 28 for driving the digital predistortion provided by predistorter 22 .
- DSP 50 provides digital implementation of Delay 3 and Delay 4 to provide correlation between the input signal 12 and the resulting amplified output signal 14 as they are provided as inputs to DSP block 28 . This ensures that the predistorter 22 addresses the distortion in the output signal 14 that may be provided by the characteristics of amplifier 10 .
- DSP block 50 of the transceiver 5 provides Delay elements 14 in FIG. 1 and provides adjustability of those elements for the purposes of implementing the precise timing control of the invention to ensure the proper operation of the envelope-tracking functions of the transceiver.
- Delay 2 is set in DSP 50 .
- the amount of Delay 2 may be configured to be somewhat significant due to inherent signal delay provided within PSU 60 .
- the large Delay 2 might be determined empirically, such as on a lab bench, and then the initial delay preloaded into DSP 50 .
- Delay 2 is preferably set to be slightly larger than the delay of the signal in the envelope tracking path 18 , which includes Delay 1 (which can be ‘fine adjusted’ to equalize the delays in the two paths), D/A converter 82 , and PSU 60 .
- Delay 3 and Delay 4 are set by DSP 50 to provide correlation at DSP block 28 for the predistorter 22 .
- Delay 4 may also be a significant delay. While DSP 50 may incorporate variable delays in both Delay 3 and Delay 4 , in one embodiment, Delay 4 might be preset or initialized to take into account the delays of the main signal path 16 and feedback path 42 , and then Delay 3 might be incrementally adjusted by DSP 50 to achieve timing alignment between the input signal in path 20 to the predistorter DSP block 28 and the feedback of the amplified output 14 , which is coupled off and fed back on path 42 .
- the delay of element Delay 4 would generally be equal to the delay associated with predistorter 22 , Delay 2 , D/A converter 24 , upconverter 26 , amplifier 10 , coupler 40 , downconverter 44 , A/D converter 46 , and Delay 3 .
- the predistorter 22 does not need to be providing predistortion, whilst PSU 60 must not be tracking and must provide a high level or maximum level signal to the power amplifier 10 .
- the DSP block 50 adjusts Delay 3 to provide correlation of the feedback signal 42 with the input signal 12 at the predistorter DSP block 28 .
- the input signal is amplified by amplifier 10 , coupled, and then fed back in path 42 to DSP block 28 .
- a portion of the input signal 12 is also coupled off on path 20 as an input to the DSP block 28 .
- Delay 3 is adjusted by DSP 50 to provide timing alignment between the input signal and the resulting feedback of the amplified output. While Delay 3 is discussed herein as being the adjusted component with Delay 4 generally fixed by DSP 50 , it may be that both Delay 3 and Delay 4 are adjusted by DSP 50 for the purpose of the timing alignment. Or, Delay 3 might be fixed and Delay 4 adjusted (or Delay 3 might be omitted and Delay 4 adjusted).
- coarse delay adjustment may be provided by DSP 50 utilizing whole clock cycles, such as by the delays provided by shift registers or FIFO stacks, for example.
- DSP 50 might provide a fine delay adjustment incorporating fractions of clock cycles, such as with a variable delay filter.
- a coarse delay adjustment might be provided by Delay 4 and a fine adjustment by Delay 3 .
- coarse delay adjustment might be provided by Delay 3 with fine delay adjustment provided by Delay 4 .
- only one delay element, Delay 3 or Delay 4 might be used and may provide both coarse and fine adjustment.
- Delay 3 Once Delay 3 has been set in the above example, the system then runs providing predistortion and updates of DSP block 28 until a steady state condition is reached in the DSP 50 and the predistortion function.
- Delay 1 and/or Delay 2 might be calibrated and adjusted utilizing DSP 50 , but without a predistortion function.
- the predistortion function is fixed.
- the LUTs might be fixed so that they are not updated from their condition as determined in the full power supply steady state condition after calibration of Delay 3 and Delay 4 .
- the tracking functionality of envelope tracking PSU 60 is enabled. PSU 60 is then responsive to the detected envelope signal 74 for varying the power delivered to amplifier 10 . That is, the power supply 60 tracks the input signal envelope.
- the DSP 50 uses adjustments to Delay 1 and/or Delay 2 to align the input signal to amplifier 10 with the power supply signal 62 .
- the DSP block 50 tracks the distortion at amplifier 10 , such as along path 42 . Since the predistortion is fixed and is not updated, the distortion in the output on path 42 is the result of misalignment between the envelope tracking signal 62 and the signal along the MSP 16 .
- the DSP block 50 tracks a minimum in the distortion of output signal 14 and adjusts Delay 1 and/or Delay 2 . In one embodiment, Delay 2 may provide coarse delay adjustments or may be fixed and Delay 1 may provide a fine delay adjustment between the output signal and the power signal 62 to amplifier 10 from PSU 60 .
- Delay 1 may provide coarse adjustment or be fixed, while Delay 2 provides fine adjustment for the purposes of alignment.
- One of the delays might provide a coarse adjustment, including entire clock cycles (e.g., shift register, FIFO stack) or might utilize a fine delay adjustment such as provided by a variable delay filter to achieve delays that are fractions of a clock cycle.
- one of Delay 1 or Delay 2 might be eliminated entirely, wherein the other element would handle both coarse and fine adjustment for the purposes of timing alignment of the input signal to amplifier 10 and the power supply signal 62 to amplifier 10 .
- the transceiver 5 runs in an appropriate fashion with the predistorter being regularly updated pursuant to feedback on path 42 .
- Delay 1 might be periodically adjusted.
- FIG. 1A illustrates another embodiment of the invention wherein the Delay 1 component has been removed and the Delay 2 component alone is utilized to align the signals in the envelope detection path 18 and the main signal path 16 at the amplifier 10 .
- FIG. 1B illustrates an embodiment of the invention wherein the Delay 2 component has been removed to provide alignment adjustment primarily through Delay 1 .
- FIG. 2 illustrates another embodiment of the invention wherein the DSP 50 incorporates a predistortion function or circuit 90 to predistort the envelope signal.
- the predistortion circuit 70 may provide any number of various suitable predistortion techniques to predistort the envelope signals 18 including, for example, an LUT predistorter. Similar to LUTs utilized for signal predistortion on the MSP, predistortion circuit 90 may be supported by DSP 92 , utilized to execute the predistortion algorithm for the envelope predistortion and also to populate and/or update the LUTs of circuit 90 and to provide overall adaptation of the predistortion circuit 90 and its operation based upon the achieved output of power amplifier 10 .
- the input signals 12 on path 91 are utilized by DSP 92 to implement the predistortion algorithm, such as to index and select LUT values in the example of an LUT predistorter.
- the amplifier output 14 that is fed back on path 42 and path 93 is also utilized by DSP 92 for updating, correcting, and adapting predistorter circuit 90 .
- DSP circuit 92 which operates in conjunction with the predistortion circuit 90 , may also implement an envelope detector (not shown) in the respective input line 91 for the purpose of utilizing the detected envelope to drive the predistortion generation process.
- the detected envelope associated with line 18 is utilized to drive the predistortion process of circuit 90 .
- Signals 91 and 93 input to the DSP 92 are converted to their respective envelopes before processing by DSP 92 .
- the corrected or predistorted envelope signal on line 74 is then converted by D/A converter 82 to an appropriate analog signal for utilization by the envelope-tracking PSU 60 .
- the predistorted envelope signal feeds the envelope modulation input of the envelope-tracking power supply 60 to thus ensure that the output voltage on line 62 provides adequate tracking of the input signal envelope on line 18 .
- a delay element 95 or Delay 5 in path 91 is used to equalize the delays to DSP 92 in the embodiment of FIG. 2 .
- the inputs to the DSP 92 are the same as those to DSP 28 as shown. In such an embodiment, the DSP 92 performs the appropriate envelope detection on the signals of paths 20 and 42 prior to further processing by the DSP 92 .
- the predistortion circuit 90 is configured and operable for predistorting the input signal envelope to address the input signal tracking capabilities of the power supply.
- the predistortion addresses the operational parameters of power supply 60 , such as the non-linearities in the transfer function of the power supply and addresses other imperfections in the tracking behavior of power supply 60 , such as slew rate limitations, for example.
- the predistortion circuit 90 may be configured to provide any desired predistortion of envelope signal 18 in order to offset the effects of the power supply 60 .
- the predistortion will be a variation from ordinary MSP predistortion.
- MSP predistortion even order components are usually set to zero to correct the intermodulation distortion (IMD) created by the odd order components in the amplifier transfer characteristic.
- IMD intermodulation distortion
- envelope predistorter even order components are also utilized and considered.
- LUT predistorter for the envelope predistortion, both odd and even order components are generated. The same holds true if polynomial predistortion of the envelope is used.
- the predistortion circuitry 90 is operable for predistorting the input signal envelope to cause over-compensation in the level of power that is supplied to the amplifier 10 to ensure proper efficient and linear amplification. That is, the predistortion algorithm provided through DSP 92 and predistortion circuit 90 might be configured to create a small margin above the required minimum envelope level at any given instant in time to ensure that the envelope-tracking process provides sufficient power to amplifier 10 so as not to degrade the intermodulation distortion (IMD) performance of the amplifier. In that way, the amplifier 10 is able to handle significant envelope peaks.
- IMD intermodulation distortion
- the present invention thus operates on the realization that the power supply output 62 does not need to precisely follow the input envelope in order to achieve the desired results of the invention. Rather, the output of supply 60 merely needs to “at least” follow the envelope or be slightly above the envelope. While the built-in over-compensation provided by the predistortion circuit 90 may result in a very small and almost negligible loss in efficiency of the overall transmitter 5 , it will ensure that adequate IMD performance is guaranteed without significantly adding to the overall system complexity. The IMD performance of the transmitter 5 is also addressed by the conventional predistortion circuitry in the MSP 16 , separate and apart from the envelope predistortion provided by the invention.
- the overcompensation provided by the predistortion circuit 90 might be related to the level of the input signal envelope.
- the predistortion might be tailored according to the envelope level. For example, for low envelope levels, the predistortion circuit 90 might be operable to predistort the envelope so that the predistorted envelope 74 closely tracks the input signal envelope 18 . However, for high envelope levels, the predistortion of the envelope by circuit 90 provides overcompensation in the envelope so the amplifier can address the higher input signal levels.
- the predistorter circuit might be configured to only predistort the envelope at higher levels above a certain threshold level.
Abstract
Description
- In wireless communication applications, such as cellular phone services or other wireless services, amplifiers are used to provide the desired signal coverage for the particular wireless application. For example, radio frequency (RF) power amplifiers are used for boosting the level of an RF signal prior to transmission of that signal. RF power amplification techniques, and particularly RF power amplification techniques used for wireless applications, have inherent drawbacks to which the industry continues to direct its efforts. Specifically, in developing an RF transmission system, considerable attention is given to amplifier efficiency and signal distortion of the amplified signal.
- Amplifier efficiency, which is generally defined as the level of RF power that may be achieved at the output signal compared to the power that is input into the overall amplification process, is conventionally somewhat low in wireless applications. Therefore, considerable attention within the power amplifier industry has been devoted to methods of enhancing power amplifier efficiency. Small increases in amplifier efficiency can provide significant benefits in a wireless system and reduce the overall costs necessary to run the system.
- Another drawback in RF power amplification, which must be addressed and taken into account with any methods for improving efficiency, is signal distortion. An RF power amplifier, to a greater or lesser extent, exerts a distorting effect on the RF signals that are amplified. Non-linearities of the amplifier, as well as other factors, contribute to the distortion. Such distortion must be controlled to ensure that the RF transmitter meets the various standards regarding RF interference.
- To address amplifier efficiency, one current technique involves the use of envelope tracking of the input signal to the amplifier and use of the detected envelope to vary the amplifier operation. In an envelope tracking system, a variable power supply is utilized for supplying power to the amplifier. The envelope power levels of the input signal are monitored, and the power that is supplied to the power amplifier, or typically to the final stage(s) of the power amplifier, is varied based on the monitored envelope levels. More specifically, the power that is supplied to the amplifier is varied so as to be just sufficient to reproduce the power level required by the amplifier at a given instant of time. Therefore, at low envelope power levels, a low supply voltage is provided to the amplifier, and the full supply voltage is provided to the amplifier only when the maximum power is required, that is, at the envelope peaks.
- However, while envelope-tracking techniques improve efficiency, it is desirable to improve upon envelope tracking features. Particularly, it is desirable to improve upon and efficiently incorporate an envelope tracking power supply into a transceiver. Furthermore, it is desirable to improve upon the efficiency and linearity of an RF power amplifier, in a transceiver system. Still further, it is desirable to utilize the digital signal processing capabilities of a transceiver for implementing envelope tracking capabilities. It is further desirable to implement such features of envelope tracking while addressing imperfections or non-linearities in the tracking behavior of the power supply,
- The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given below, serve to explain the principles of the invention.
-
FIG. 1 illustrates an embodiment of the present invention or an envelope-tracking power amplifier in a transceiver. -
FIG. 1A illustrates an alternative embodiment of the present invention. -
FIG. 1B illustrates another alternative embodiment of the present invention. -
FIG. 2 illustrates an alternative embodiment of the circuit ofFIG. 1 utilizing predistortion of an envelope signal. -
FIG. 2A illustrates another alternative embodiment of the circuit ofFIG. 1 utilizing predistortion of an envelope signal. - The present invention addresses the above-noted drawbacks in the prior art, and specifically addresses the utilization of an envelope tracking power supply in a transceiver. Specifically, the present invention utilizes digital signal processing within a transceiver to perform envelope extraction and provide appropriate Delay matching of the envelope and main signal paths. In another embodiment, predistortion of the envelope signal is utilized to address non-linearities in the envelope tracking power supply.
-
FIG. 1 illustrates one embodiment of the present invention utilized to improve the performance, efficiency and cost-effectiveness of a transceiver system. For example, referring toFIG. 1 , the overall transceiver system, ortransceiver 5, includes an amplification device oramplifier 10, such as an RF power amplifier that produces anRF output signal 14 in response to aninput signal 12. Theinput signal 12 is a digital signal that is processed by theDSP 50, converted to analog and then appropriately upconverted to RF prior to amplification byamplifier 10. Thepower amplifier 10 may be a single stage or multiple stage amplifier of a suitable variety for RF power amplification. In thetransceiver 5 illustrated inFIG. 1 , generally theinput signal 12 is directed along several different paths for realizing the various aspects of the invention. For the purposes of discussion herein, only the transmit side of thetransceiver 5 is illustrated. However, a person of ordinary skill in the art will realize that a receiver path is also generally part of a transceiver. - The
input signal 12 is directed along a main signal path (MSP) 16 to be amplified byamplifier 10. Theinput signal 12 is also coupled to an envelope-tracking path 18 and is coupled to asignal processing path 20 inFIG. 1 . Along theMSP 16,input signal 12 proceeds to the input ofamplifier 10, where it is amplified and produced as anoutput signal 14. In the MSP, the input signal may be further processed for improving the operation of the RF power amplifier. For example, as shown inFIG. 1 , a signal in theMSP 16 may be predistorted, either digitally or in an analog fashion, to address non-linearities in thepower amplifier 10, according to known predistortion principles. Of course, other linearization techniques might also be utilized along the MSP to address non-linearities in theamplifier 10. For the purposes of illustrating one embodiment of the present invention, the predistortion of the input signal along theMSP 16 is disclosed in the Figures as digital predistortion and various digital predistortion techniques may be used. However, it would be understood by a person of ordinary skill in the art, that various other linearization techniques, digital or analog, might be utilized along theMSP 16 for addressing amplifier non-linearities and distortion and for enhancing the performance ofpower amplifier 10. The present invention is thus not limited to the linearity techniques or predistortion techniques of the MSP that are illustrated or specifically discussed. - Referring again to
FIG. 1 , the input signal orsignals 12 are shown in a digital form as quadrature I/Q signals, which, along theMSP 16, are directed to a predistortion circuit incorporated in theDSP 50 that includespredistorter 22 and algorithm/update circuitry 28. Thepredistorter 22 predistorts theinput signal 12, whereupon the predistorted input signal is converted to an analog signal by a D/A converter 24 and upconverted from baseband to RF byupconversion circuitry 26. The RF signal is then amplified by theRF power amplifier 10 to produce analogRF output signal 14. - A
digital predistorter 22, which may be a lookup table (LUT) circuit, for example, will generally include additional digital signal processing (DSP)circuitry 28, which includes signal processing circuitry for implementing the digital predistortion algorithm, and any updating or adaptation of the predistortion circuit. For example, if look-up table (LUT) predistortion is used, the LUTs ofpredistorter 22 may need to be adaptively populated and updated, which may be handled by the DSP 28. Furthermore, any correction or updates to the predistortion is handled by theDSP 28. - Generally, according to known LUT predistortion principles, the I/
Q input signals 12 are directed viapath 20 to theDSP 28 and are utilized to drive the predistortion process. For example, theDSP 28, viapath 32, may utilize the values of the I/Q input signals to index and look up corresponding predistortion I/Q values in the respective LUTs. DSP 28 can also be utilized to adaptively update the values of the LUTs inpredistorter 22, or to provide additional correction algorithms through thepredistorter 22 according to known digital predistortion techniques. - Referring to
FIG. 1 , acoupler 40 might be utilized to couple a portion of theanalog output signal 14 to DSP 28 as a feedback signal alongfeedback path 42, which includesappropriate downconversion circuitry 44 and A/D conversion circuitry 46. DSP 28 utilizes the output feedback signal onpath 42 to adapt thepredistorter 22 based upon the knowledge of the performance of the predistortion that is provided by thatfeedback signal 42. Generally,digital predistortion circuits 22 and the supportingDSP 28 will all be incorporated together within a larger overall DSP circuit or block indicated byreference numeral 50 inFIG. 1 . However, separate blocks or circuits might also be utilized. Accordingly, the present invention is not limited to specific layouts or positions of the DSP blocks, which handle the predistortion and/or the adaptation of the predistortion, as well as the timing alignment of the various signals of the transceiver. Furthermore, as discussed further below, a delay element 86 (Delay 3) is incorporated intofeedback path 42 for correlating the predistortion updating and predistortion algorithm with theinput signal 12. - In the present invention, an envelope-tracking
power supply 60 is utilized and is coupled topower amplifier 10 for supplying power to the amplifier viapath 62. As noted above, in an envelope-tracking power supply, thepower supply 60 is operable for tracking the input signal envelope, derived frompath 18 in order to vary the level of power supplied to theamplifier 10 in response to variation of the input signal envelope. More specifically, the power supplied toamplifier 10 viapower supply 60 is varied so as to be sufficient to reproduce, at theamplifier output 14, the power level required at a given instant. Therefore, at low envelope power levels, a low supply voltage is provided toamplifier 10. A full supply voltage is only provided when maximum envelope power is required, such as at the envelope peaks of the input signal. - Referring again to
FIG. 1 , the present invention utilizes envelope tracking to improve the operation of the transceiver and specifically to improve the operation and efficiency ofamplifier 10. The invention incorporates digital envelope detection from adigital envelope detector 70.Digital envelope detector 70 may be a stand-alone function in theDSP 50, or it may be incorporated into other digital signal processing features of the DSP oftransceiver 5. - The present invention exploits the superior capabilities of the digital signal processing within a transceiver to perform the envelope extraction and modulation functions for the envelope tracking
power supply 60. Furthermore, the invention utilizes the digital signal processing functions of the transceiver to achieve suitable envelope tracking advantages by providing the appropriate timing and delay matching of the envelope tracking and main signal paths. - More specifically, in one embodiment, the
transceiver 5 utilizes digitalsignal processing block 50 to achieve peak-to-average signal reduction, such as crest factor reduction (CFR) 72. TheCFR 72 uses envelope detection. Thetransceiver 5 utilizes the digitalenvelope detection function 70 of theCFR function 72 for the purposes of incorporating an envelope-trackingPSU 60. In that way, the digitalenvelope detection functionality 70 of the transceiver may be incorporated for various different purposes, including envelope tracking, providing an overall efficiency improvement and lower cost in the design of theDSP block 50 of the transceiver, while providing the power efficiency of envelope tracking. - The
input signal 12 is coupled from theMSP 16 ontopath 18 where it is directed todigital envelope detector 70, which is shown as part of the CFR function. Because the input signal envelope is utilized for the purposes of an envelope-tracking power supply, the digital signal processing (DSP)block 50 utilizesdigital envelope detector 70 to extract magnitude information of the input signal with respect to envelope detection. For example, one type of envelope detector is noted by the relationship:
env=√{square root over (I 2 +Q 2)}
Utilizing the detected envelope, theDSP block 50 provides anenvelope signal 74 toPSU 60. ThePSU 60 then uses theenvelope signal 74 to drive thePSU 60 and thereby output a signal onpath 62 that meets the power requirements ofpower amplifier 10. - In accordance with another aspect of the present invention,
DSP block 50 oftransceiver 5 provides precise timing control of the signals in the system by accurately matching the delays between the envelope tracking 18 andmain signal paths 16 to ensure that the envelope-varyingsupply voltage 62 has the correct timing alignment with the input signal to theamplifier 10. The present invention thus provides an efficient, cost-effective DSP implementation of timing control in a transceiver utilizing an envelope-tracking amplifier. - In the prior art, such timing alignment for the purposes of an
envelope tracking PSU 60 would otherwise require significant lengths of co-axial cable or expensive delay filters in order to achieve the required alignment. The present invention eliminates such bulky and expensive components and provides a transceiver that incorporates envelope tracking capabilities and timing alignment features all in thesame DSP block 50. - Referring to
FIG. 1 , theDSP block 50 incorporates a number of delays within themain signal path 16, the envelope-trackingpath 18 and theprocessing paths DSP block 50 ensures thatPSU 60 provides appropriate power to theamplifier 10 to coincide with peaks in the envelope of theinput signal 12. Furthermore, the DSP provides proper alignment in the digital predistortion algorithm ofblock 28 to ensure that the proper correction is provided via predistortion frompredistorter 22 for a correlatedinput signal 12. - More specifically, in the
envelope detection path 18,DSP block 50 incorporates adelay element 80 referred to asDelay 1. Digital-to-analog converter 82 is also utilized to convert the digitally detected envelope signal fromDelay 1 into an appropriate analog signal for use byPSU 60. Anotherdelay element 84, also referred to herein as Delay 2, is provided in themain signal path 16.Delay 1 and Delay 2 are utilized to provide correlation between the peaks of theinput signal 12 and thepower signal 62 provided toamplifier 10 byPSU 60. This provides sufficient power to theamplifier 10 to handle input signal peaks. While the embodiment illustrated inFIG. 1 shows two delay elements (Delay 1, Delay 2), it may be suitable to utilize only one delay element. For example, the inherent delay in the envelope-trackingpath 18 may be significant due to the operation of the power supply and, thus, it may be suitable to eliminateDelay 1 and only utilize Delay 2. Alternatively, Delay 2 might be eliminated and only Delay one utilized. In one aspect of the invention,Delay 1 may provide fine-tuning of timing, whereas Delay 2 may provide a coarser delay control, or vice versa. - In another aspect of the present invention, a
Delay element 86 is incorporated into a feedback path indicated byreference numeral 42.Delay component 86 is also referred to asDelay 3. ADelay element 88, also referred to asDelay 4, is incorporated into theprocessing path 20, which provides a portion of the input signal to DSP block 28 for driving the digital predistortion provided bypredistorter 22. - In accordance with one aspect of the invention,
DSP 50 provides digital implementation ofDelay 3 andDelay 4 to provide correlation between theinput signal 12 and the resulting amplifiedoutput signal 14 as they are provided as inputs toDSP block 28. This ensures that thepredistorter 22 addresses the distortion in theoutput signal 14 that may be provided by the characteristics ofamplifier 10.DSP block 50 of thetransceiver 5 providesDelay elements 14 inFIG. 1 and provides adjustability of those elements for the purposes of implementing the precise timing control of the invention to ensure the proper operation of the envelope-tracking functions of the transceiver. - Specifically, in order to realize the delays provided by
DSP block 50 in accordance with the principles of the present invention, calibration is utilized for the delays. First, in addressing the timing alignment inMSP 16 andenvelope tracking path 18, Delay 2 is set inDSP 50. The amount of Delay 2 may be configured to be somewhat significant due to inherent signal delay provided withinPSU 60. In one embodiment of the invention, the large Delay 2 might be determined empirically, such as on a lab bench, and then the initial delay preloaded intoDSP 50. Delay 2 is preferably set to be slightly larger than the delay of the signal in theenvelope tracking path 18, which includes Delay 1 (which can be ‘fine adjusted’ to equalize the delays in the two paths), D/A converter 82, andPSU 60. Next, after Delay 2 is initialized,Delay 3 andDelay 4 are set byDSP 50 to provide correlation atDSP block 28 for thepredistorter 22. - Specifically, the envelope tracking features of
DSP 50 and thetransceiver 5 are disabled so that full power is provided toamplifier 10 throughsignal 62.Delay 4 may also be a significant delay. WhileDSP 50 may incorporate variable delays in bothDelay 3 andDelay 4, in one embodiment,Delay 4 might be preset or initialized to take into account the delays of themain signal path 16 andfeedback path 42, and then Delay 3 might be incrementally adjusted byDSP 50 to achieve timing alignment between the input signal inpath 20 to thepredistorter DSP block 28 and the feedback of the amplifiedoutput 14, which is coupled off and fed back onpath 42. The delay ofelement Delay 4 would generally be equal to the delay associated withpredistorter 22, Delay 2, D/A converter 24,upconverter 26,amplifier 10,coupler 40,downconverter 44, A/D converter 46, andDelay 3. For the purposes of calibratingDelay 3/Delay 4, thepredistorter 22 does not need to be providing predistortion, whilstPSU 60 must not be tracking and must provide a high level or maximum level signal to thepower amplifier 10. With a non-tracking power supply and anappropriate input signal 12, theDSP block 50 adjustsDelay 3 to provide correlation of thefeedback signal 42 with theinput signal 12 at thepredistorter DSP block 28. Specifically, the input signal is amplified byamplifier 10, coupled, and then fed back inpath 42 toDSP block 28. A portion of theinput signal 12 is also coupled off onpath 20 as an input to theDSP block 28.Delay 3 is adjusted byDSP 50 to provide timing alignment between the input signal and the resulting feedback of the amplified output. WhileDelay 3 is discussed herein as being the adjusted component withDelay 4 generally fixed byDSP 50, it may be that bothDelay 3 andDelay 4 are adjusted byDSP 50 for the purpose of the timing alignment. Or,Delay 3 might be fixed andDelay 4 adjusted (orDelay 3 might be omitted andDelay 4 adjusted). - In the adjustment of
Delay 3 and/orDelay 4, coarse delay adjustment may be provided byDSP 50 utilizing whole clock cycles, such as by the delays provided by shift registers or FIFO stacks, for example. Alternatively,DSP 50 might provide a fine delay adjustment incorporating fractions of clock cycles, such as with a variable delay filter. In one embodiment, a coarse delay adjustment might be provided byDelay 4 and a fine adjustment byDelay 3. In an alternative embodiment, coarse delay adjustment might be provided byDelay 3 with fine delay adjustment provided byDelay 4. In still another embodiment, only one delay element,Delay 3 orDelay 4, might be used and may provide both coarse and fine adjustment. - Once
Delay 3 has been set in the above example, the system then runs providing predistortion and updates ofDSP block 28 until a steady state condition is reached in theDSP 50 and the predistortion function. - After steady state is reached,
Delay 1 and/or Delay 2 might be calibrated and adjusted utilizingDSP 50, but without a predistortion function. Specifically, for the purposes of calibratingDelay 1 and/or Delay 2, the predistortion function is fixed. For example, the LUTs might be fixed so that they are not updated from their condition as determined in the full power supply steady state condition after calibration ofDelay 3 andDelay 4. Simultaneously with setting the predistortion function, the tracking functionality ofenvelope tracking PSU 60 is enabled.PSU 60 is then responsive to the detectedenvelope signal 74 for varying the power delivered toamplifier 10. That is, thepower supply 60 tracks the input signal envelope. TheDSP 50 then uses adjustments to Delay 1 and/or Delay 2 to align the input signal toamplifier 10 with thepower supply signal 62. - When the
signal 62 fromPSU 60 toamplifier 10 does not track properly to provide maximum power corresponding with various peaks of theinput signal 12 along themain signal path 16, distortion results inamplifier 10. TheDSP block 50 tracks the distortion atamplifier 10, such as alongpath 42. Since the predistortion is fixed and is not updated, the distortion in the output onpath 42 is the result of misalignment between theenvelope tracking signal 62 and the signal along theMSP 16. TheDSP block 50 tracks a minimum in the distortion ofoutput signal 14 and adjustsDelay 1 and/or Delay 2. In one embodiment, Delay 2 may provide coarse delay adjustments or may be fixed andDelay 1 may provide a fine delay adjustment between the output signal and thepower signal 62 toamplifier 10 fromPSU 60. In an alternative embodiment,Delay 1 may provide coarse adjustment or be fixed, while Delay 2 provides fine adjustment for the purposes of alignment. One of the delays might provide a coarse adjustment, including entire clock cycles (e.g., shift register, FIFO stack) or might utilize a fine delay adjustment such as provided by a variable delay filter to achieve delays that are fractions of a clock cycle. In another embodiment of the invention, one ofDelay 1 or Delay 2 might be eliminated entirely, wherein the other element would handle both coarse and fine adjustment for the purposes of timing alignment of the input signal toamplifier 10 and thepower supply signal 62 toamplifier 10. - Once
Delay 1 and/or Delay 2 has been adjusted to provide the desired alignment, thetransceiver 5 runs in an appropriate fashion with the predistorter being regularly updated pursuant to feedback onpath 42.Delay 1 might be periodically adjusted. -
FIG. 1A illustrates another embodiment of the invention wherein theDelay 1 component has been removed and the Delay 2 component alone is utilized to align the signals in theenvelope detection path 18 and themain signal path 16 at theamplifier 10.FIG. 1B illustrates an embodiment of the invention wherein the Delay 2 component has been removed to provide alignment adjustment primarily throughDelay 1. -
FIG. 2 illustrates another embodiment of the invention wherein theDSP 50 incorporates a predistortion function orcircuit 90 to predistort the envelope signal. Thepredistortion circuit 70 may provide any number of various suitable predistortion techniques to predistort the envelope signals 18 including, for example, an LUT predistorter. Similar to LUTs utilized for signal predistortion on the MSP,predistortion circuit 90 may be supported byDSP 92, utilized to execute the predistortion algorithm for the envelope predistortion and also to populate and/or update the LUTs ofcircuit 90 and to provide overall adaptation of thepredistortion circuit 90 and its operation based upon the achieved output ofpower amplifier 10. To that end, the input signals 12 onpath 91 are utilized byDSP 92 to implement the predistortion algorithm, such as to index and select LUT values in the example of an LUT predistorter. Similarly, theamplifier output 14 that is fed back onpath 42 andpath 93 is also utilized byDSP 92 for updating, correcting, and adaptingpredistorter circuit 90.DSP circuit 92, which operates in conjunction with thepredistortion circuit 90, may also implement an envelope detector (not shown) in therespective input line 91 for the purpose of utilizing the detected envelope to drive the predistortion generation process. For the envelope predistortion, the detected envelope associated withline 18 is utilized to drive the predistortion process ofcircuit 90. If an LUT predistortion is utilized, a stream of digital samples of the envelope is fed toDSP 92 that operates on the envelope signals (e.g. env=√{square root over (I2+Q2)}) and provides desired driving signals for thepredistorter 90.Signals DSP 92 are converted to their respective envelopes before processing byDSP 92. - The corrected or predistorted envelope signal on
line 74 is then converted by D/A converter 82 to an appropriate analog signal for utilization by the envelope-trackingPSU 60. Specifically, the predistorted envelope signal feeds the envelope modulation input of the envelope-trackingpower supply 60 to thus ensure that the output voltage online 62 provides adequate tracking of the input signal envelope online 18. Adelay element 95 orDelay 5 inpath 91 is used to equalize the delays toDSP 92 in the embodiment ofFIG. 2 . In another embodiment as illustrated inFIG. 2A , the inputs to theDSP 92 are the same as those toDSP 28 as shown. In such an embodiment, theDSP 92 performs the appropriate envelope detection on the signals ofpaths DSP 92. - In one aspect of the invention, the
predistortion circuit 90 is configured and operable for predistorting the input signal envelope to address the input signal tracking capabilities of the power supply. The predistortion addresses the operational parameters ofpower supply 60, such as the non-linearities in the transfer function of the power supply and addresses other imperfections in the tracking behavior ofpower supply 60, such as slew rate limitations, for example. - The
predistortion circuit 90 may be configured to provide any desired predistortion ofenvelope signal 18 in order to offset the effects of thepower supply 60. In one aspect of the invention, the predistortion will be a variation from ordinary MSP predistortion. For example, in MSP predistortion, even order components are usually set to zero to correct the intermodulation distortion (IMD) created by the odd order components in the amplifier transfer characteristic. For the envelope predistorter, however, even order components are also utilized and considered. For example, using an LUT predistorter for the envelope predistortion, both odd and even order components are generated. The same holds true if polynomial predistortion of the envelope is used. - In accordance with another aspect of the present invention, the
predistortion circuitry 90 is operable for predistorting the input signal envelope to cause over-compensation in the level of power that is supplied to theamplifier 10 to ensure proper efficient and linear amplification. That is, the predistortion algorithm provided throughDSP 92 andpredistortion circuit 90 might be configured to create a small margin above the required minimum envelope level at any given instant in time to ensure that the envelope-tracking process provides sufficient power to amplifier 10 so as not to degrade the intermodulation distortion (IMD) performance of the amplifier. In that way, theamplifier 10 is able to handle significant envelope peaks. The present invention thus operates on the realization that thepower supply output 62 does not need to precisely follow the input envelope in order to achieve the desired results of the invention. Rather, the output ofsupply 60 merely needs to “at least” follow the envelope or be slightly above the envelope. While the built-in over-compensation provided by thepredistortion circuit 90 may result in a very small and almost negligible loss in efficiency of theoverall transmitter 5, it will ensure that adequate IMD performance is guaranteed without significantly adding to the overall system complexity. The IMD performance of thetransmitter 5 is also addressed by the conventional predistortion circuitry in theMSP 16, separate and apart from the envelope predistortion provided by the invention. - In an alternative embodiment of the invention, the overcompensation provided by the
predistortion circuit 90 might be related to the level of the input signal envelope. In such a case, the predistortion might be tailored according to the envelope level. For example, for low envelope levels, thepredistortion circuit 90 might be operable to predistort the envelope so that thepredistorted envelope 74 closely tracks theinput signal envelope 18. However, for high envelope levels, the predistortion of the envelope bycircuit 90 provides overcompensation in the envelope so the amplifier can address the higher input signal levels. In still another alternative, the predistorter circuit might be configured to only predistort the envelope at higher levels above a certain threshold level. - Further discussion and embodiments for providing envelope tracking signal predistortion are set forth in U.S. patent application Ser. No. 11/016,508, entitled “A Transmitter with an Envelope Tracking Power Amplifier Utilizing Digital Predistortion of the Signal Envelope,” and filed on Dec. 17, 2004, which application is incorporated herein by reference in its entirety
- While the present invention has been illustrated by a description of various embodiments and while these embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept.
Claims (40)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/073,535 US20060199553A1 (en) | 2005-03-07 | 2005-03-07 | Integrated transceiver with envelope tracking |
US12/257,944 US7715811B2 (en) | 2005-03-07 | 2008-10-24 | Integrated transceiver with envelope tracking |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/073,535 US20060199553A1 (en) | 2005-03-07 | 2005-03-07 | Integrated transceiver with envelope tracking |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/257,944 Division US7715811B2 (en) | 2005-03-07 | 2008-10-24 | Integrated transceiver with envelope tracking |
Publications (1)
Publication Number | Publication Date |
---|---|
US20060199553A1 true US20060199553A1 (en) | 2006-09-07 |
Family
ID=36944726
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/073,535 Abandoned US20060199553A1 (en) | 2005-03-07 | 2005-03-07 | Integrated transceiver with envelope tracking |
US12/257,944 Expired - Fee Related US7715811B2 (en) | 2005-03-07 | 2008-10-24 | Integrated transceiver with envelope tracking |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/257,944 Expired - Fee Related US7715811B2 (en) | 2005-03-07 | 2008-10-24 | Integrated transceiver with envelope tracking |
Country Status (1)
Country | Link |
---|---|
US (2) | US20060199553A1 (en) |
Cited By (35)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070178854A1 (en) * | 2006-01-27 | 2007-08-02 | Sehat Sutardja | Variable power adaptive transmitter |
US20070178860A1 (en) * | 2006-01-27 | 2007-08-02 | Sehat Sutardja | Variable power adaptive transmitter |
EP2306638A1 (en) * | 2009-09-30 | 2011-04-06 | Alcatel Lucent | Envelope tracking amplifier arrangement |
US20110260790A1 (en) * | 2010-04-22 | 2011-10-27 | Samsung Electronics Co., Ltd. | Dual time alignment architecture for transmitters using eer/et amplifiers and others |
US20120021695A1 (en) * | 2010-07-23 | 2012-01-26 | Motorola, Inc. | Method and Apparatus for Improving Efficiency in a Power Supply Modulated System |
WO2012114217A1 (en) * | 2011-02-22 | 2012-08-30 | Koninklijke Philips Electronics N.V. | Mri rf power amplifier with modulated power supply |
WO2012170831A1 (en) * | 2011-06-08 | 2012-12-13 | Broadcom Corporation | Method of calibrating the delay of an envelope tracking signal |
US8483633B2 (en) | 2010-07-23 | 2013-07-09 | Motorola Solutions, Inc. | Method and apparatus for alarming in a power supply modulated system |
US20130194979A1 (en) * | 2012-01-31 | 2013-08-01 | Rf Micro Devices, Inc. | Optimal switching frequency for envelope tracking power supply |
US8718579B2 (en) | 2012-03-04 | 2014-05-06 | Quantance, Inc. | Envelope tracking power amplifier system with delay calibration |
US8913967B2 (en) | 2010-04-20 | 2014-12-16 | Rf Micro Devices, Inc. | Feedback based buck timing of a direct current (DC)-DC converter |
CN104300915A (en) * | 2013-07-18 | 2015-01-21 | 英特尔移动通信有限责任公司 | Systems and methods utilizing adaptive envelope tracking |
US8942651B2 (en) | 2010-04-20 | 2015-01-27 | Rf Micro Devices, Inc. | Cascaded converged power amplifier |
US8942650B2 (en) | 2010-04-20 | 2015-01-27 | Rf Micro Devices, Inc. | RF PA linearity requirements based converter operating mode selection |
US8947157B2 (en) | 2010-04-20 | 2015-02-03 | Rf Micro Devices, Inc. | Voltage multiplier charge pump buck |
US8958763B2 (en) | 2010-04-20 | 2015-02-17 | Rf Micro Devices, Inc. | PA bias power supply undershoot compensation |
US8983407B2 (en) | 2010-04-20 | 2015-03-17 | Rf Micro Devices, Inc. | Selectable PA bias temperature compensation circuitry |
US8983409B2 (en) | 2010-04-19 | 2015-03-17 | Rf Micro Devices, Inc. | Auto configurable 2/3 wire serial interface |
US8983410B2 (en) | 2010-04-20 | 2015-03-17 | Rf Micro Devices, Inc. | Configurable 2-wire/3-wire serial communications interface |
US8989685B2 (en) | 2010-04-20 | 2015-03-24 | Rf Micro Devices, Inc. | Look-up table based configuration of multi-mode multi-band radio frequency power amplifier circuitry |
US9008597B2 (en) | 2010-04-20 | 2015-04-14 | Rf Micro Devices, Inc. | Direct current (DC)-DC converter having a multi-stage output filter |
US9020452B2 (en) | 2010-02-01 | 2015-04-28 | Rf Micro Devices, Inc. | Envelope power supply calibration of a multi-mode radio frequency power amplifier |
US9030256B2 (en) | 2010-04-20 | 2015-05-12 | Rf Micro Devices, Inc. | Overlay class F choke |
US9048787B2 (en) | 2010-04-20 | 2015-06-02 | Rf Micro Devices, Inc. | Combined RF detector and RF attenuator with concurrent outputs |
US9077405B2 (en) | 2010-04-20 | 2015-07-07 | Rf Micro Devices, Inc. | High efficiency path based power amplifier circuitry |
US9166471B1 (en) | 2009-03-13 | 2015-10-20 | Rf Micro Devices, Inc. | 3D frequency dithering for DC-to-DC converters used in multi-mode cellular transmitters |
US9184701B2 (en) | 2010-04-20 | 2015-11-10 | Rf Micro Devices, Inc. | Snubber for a direct current (DC)-DC converter |
US9214865B2 (en) | 2010-04-20 | 2015-12-15 | Rf Micro Devices, Inc. | Voltage compatible charge pump buck and buck power supplies |
US9214900B2 (en) | 2010-04-20 | 2015-12-15 | Rf Micro Devices, Inc. | Interference reduction between RF communications bands |
US9362825B2 (en) | 2010-04-20 | 2016-06-07 | Rf Micro Devices, Inc. | Look-up table based configuration of a DC-DC converter |
US9553550B2 (en) | 2010-04-20 | 2017-01-24 | Qorvo Us, Inc. | Multiband RF switch ground isolation |
US9577590B2 (en) | 2010-04-20 | 2017-02-21 | Qorvo Us, Inc. | Dual inductive element charge pump buck and buck power supplies |
US9762184B2 (en) | 2013-03-15 | 2017-09-12 | Quantance, Inc. | Envelope tracking system with internal power amplifier characterization |
US9794884B2 (en) | 2013-03-14 | 2017-10-17 | Quantance, Inc. | Envelope tracking system with adjustment for noise |
US9900204B2 (en) | 2010-04-20 | 2018-02-20 | Qorvo Us, Inc. | Multiple functional equivalence digital communications interface |
Families Citing this family (121)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7929917B1 (en) * | 2007-12-21 | 2011-04-19 | Nortel Networks Limited | Enhanced wideband transceiver |
US9112452B1 (en) | 2009-07-14 | 2015-08-18 | Rf Micro Devices, Inc. | High-efficiency power supply for a modulated load |
KR101118919B1 (en) * | 2009-07-27 | 2012-02-27 | 주식회사 에이스테크놀로지 | Base station antenna device with built-in transmitting and receiving module |
US8509713B2 (en) * | 2009-12-21 | 2013-08-13 | Ubidyne, Inc. | Single envelope tracking system for an active antenna array |
US8265572B2 (en) * | 2009-12-21 | 2012-09-11 | Ubidyne, Inc. | Multiple envelope tracking system for an active antenna array |
US9431974B2 (en) | 2010-04-19 | 2016-08-30 | Qorvo Us, Inc. | Pseudo-envelope following feedback delay compensation |
US8981848B2 (en) | 2010-04-19 | 2015-03-17 | Rf Micro Devices, Inc. | Programmable delay circuitry |
US8633766B2 (en) | 2010-04-19 | 2014-01-21 | Rf Micro Devices, Inc. | Pseudo-envelope follower power management system with high frequency ripple current compensation |
US9099961B2 (en) | 2010-04-19 | 2015-08-04 | Rf Micro Devices, Inc. | Output impedance compensation of a pseudo-envelope follower power management system |
EP3376667B1 (en) | 2010-04-19 | 2021-07-28 | Qorvo US, Inc. | Pseudo-envelope following power management system |
US9954436B2 (en) | 2010-09-29 | 2018-04-24 | Qorvo Us, Inc. | Single μC-buckboost converter with multiple regulated supply outputs |
US8782107B2 (en) | 2010-11-16 | 2014-07-15 | Rf Micro Devices, Inc. | Digital fast CORDIC for envelope tracking generation |
US20120142304A1 (en) * | 2010-12-02 | 2012-06-07 | Ofir Degani | Power Amplifiers for Wireless Systems |
US8588713B2 (en) | 2011-01-10 | 2013-11-19 | Rf Micro Devices, Inc. | Power management system for multi-carriers transmitter |
US8611402B2 (en) | 2011-02-02 | 2013-12-17 | Rf Micro Devices, Inc. | Fast envelope system calibration |
EP2673880B1 (en) * | 2011-02-07 | 2017-09-06 | Qorvo US, Inc. | Group delay calibration method for power amplifier envelope tracking |
US8624760B2 (en) | 2011-02-07 | 2014-01-07 | Rf Micro Devices, Inc. | Apparatuses and methods for rate conversion and fractional delay calculation using a coefficient look up table |
GB2489497A (en) * | 2011-03-31 | 2012-10-03 | Nujira Ltd | Matching the properties of the envelope path to the properties of the main signal path in an envelope tracking amplifier |
US9247496B2 (en) | 2011-05-05 | 2016-01-26 | Rf Micro Devices, Inc. | Power loop control based envelope tracking |
US9246460B2 (en) | 2011-05-05 | 2016-01-26 | Rf Micro Devices, Inc. | Power management architecture for modulated and constant supply operation |
US9379667B2 (en) | 2011-05-05 | 2016-06-28 | Rf Micro Devices, Inc. | Multiple power supply input parallel amplifier based envelope tracking |
GB2490892A (en) * | 2011-05-16 | 2012-11-21 | Nujira Ltd | Delay and amplitude matching of the main and envelope paths in an envelope-tracking RF amplifier |
GB2491186A (en) * | 2011-05-27 | 2012-11-28 | Nujira Ltd | A combined analogue and digital interface for the envelope path of an envelope-tracking amplifier |
EP2715945B1 (en) | 2011-05-31 | 2017-02-01 | Qorvo US, Inc. | Rugged iq receiver based rf gain measurements |
US9019011B2 (en) | 2011-06-01 | 2015-04-28 | Rf Micro Devices, Inc. | Method of power amplifier calibration for an envelope tracking system |
US9197175B2 (en) * | 2011-06-08 | 2015-11-24 | Broadcom Corporation | Methods and systems for pre-emphasis of an envelope tracking power amplifier supply voltage |
US8760228B2 (en) | 2011-06-24 | 2014-06-24 | Rf Micro Devices, Inc. | Differential power management and power amplifier architecture |
US8952710B2 (en) | 2011-07-15 | 2015-02-10 | Rf Micro Devices, Inc. | Pulsed behavior modeling with steady state average conditions |
WO2013012787A2 (en) | 2011-07-15 | 2013-01-24 | Rf Micro Devices, Inc. | Modified switching ripple for envelope tracking system |
US9263996B2 (en) | 2011-07-20 | 2016-02-16 | Rf Micro Devices, Inc. | Quasi iso-gain supply voltage function for envelope tracking systems |
US8618868B2 (en) | 2011-08-17 | 2013-12-31 | Rf Micro Devices, Inc. | Single charge-pump buck-boost for providing independent voltages |
WO2013033700A1 (en) | 2011-09-02 | 2013-03-07 | Rf Micro Devices, Inc. | Split vcc and common vcc power management architecture for envelope tracking |
US9041464B2 (en) * | 2011-09-16 | 2015-05-26 | Qualcomm Incorporated | Circuitry for reducing power consumption |
US20130076418A1 (en) * | 2011-09-27 | 2013-03-28 | Intel Mobile Communications GmbH | System and Method for Calibration of Timing Mismatch for Envelope Tracking Transmit Systems |
US8957728B2 (en) | 2011-10-06 | 2015-02-17 | Rf Micro Devices, Inc. | Combined filter and transconductance amplifier |
US9484797B2 (en) | 2011-10-26 | 2016-11-01 | Qorvo Us, Inc. | RF switching converter with ripple correction |
CN103959189B (en) | 2011-10-26 | 2015-12-23 | 射频小型装置公司 | Based on the parallel amplifier phase compensation of inductance |
US9024688B2 (en) | 2011-10-26 | 2015-05-05 | Rf Micro Devices, Inc. | Dual parallel amplifier based DC-DC converter |
US9294041B2 (en) | 2011-10-26 | 2016-03-22 | Rf Micro Devices, Inc. | Average frequency control of switcher for envelope tracking |
US8975959B2 (en) | 2011-11-30 | 2015-03-10 | Rf Micro Devices, Inc. | Monotonic conversion of RF power amplifier calibration data |
US9515621B2 (en) | 2011-11-30 | 2016-12-06 | Qorvo Us, Inc. | Multimode RF amplifier system |
US9250643B2 (en) | 2011-11-30 | 2016-02-02 | Rf Micro Devices, Inc. | Using a switching signal delay to reduce noise from a switching power supply |
US9256234B2 (en) | 2011-12-01 | 2016-02-09 | Rf Micro Devices, Inc. | Voltage offset loop for a switching controller |
US9280163B2 (en) | 2011-12-01 | 2016-03-08 | Rf Micro Devices, Inc. | Average power tracking controller |
WO2013082384A1 (en) | 2011-12-01 | 2013-06-06 | Rf Micro Devices, Inc. | Rf power converter |
US9041365B2 (en) | 2011-12-01 | 2015-05-26 | Rf Micro Devices, Inc. | Multiple mode RF power converter |
US8947161B2 (en) | 2011-12-01 | 2015-02-03 | Rf Micro Devices, Inc. | Linear amplifier power supply modulation for envelope tracking |
US9494962B2 (en) | 2011-12-02 | 2016-11-15 | Rf Micro Devices, Inc. | Phase reconfigurable switching power supply |
US9813036B2 (en) | 2011-12-16 | 2017-11-07 | Qorvo Us, Inc. | Dynamic loadline power amplifier with baseband linearization |
US9298198B2 (en) | 2011-12-28 | 2016-03-29 | Rf Micro Devices, Inc. | Noise reduction for envelope tracking |
GB2498391B (en) * | 2012-01-16 | 2018-11-21 | Snaptrack Inc | Pre-distortion in RF path in combination with shaping table in envelope path for envelope tracking amplifier |
US8981839B2 (en) | 2012-06-11 | 2015-03-17 | Rf Micro Devices, Inc. | Power source multiplexer |
CN104662792B (en) | 2012-07-26 | 2017-08-08 | Qorvo美国公司 | Programmable RF notch filters for envelope-tracking |
US8934854B2 (en) * | 2012-08-29 | 2015-01-13 | Crestcom, Inc. | Transmitter with peak-tracking PAPR reduction and method therefor |
US9225231B2 (en) | 2012-09-14 | 2015-12-29 | Rf Micro Devices, Inc. | Open loop ripple cancellation circuit in a DC-DC converter |
US9197256B2 (en) * | 2012-10-08 | 2015-11-24 | Rf Micro Devices, Inc. | Reducing effects of RF mixer-based artifact using pre-distortion of an envelope power supply signal |
US9207692B2 (en) | 2012-10-18 | 2015-12-08 | Rf Micro Devices, Inc. | Transitioning from envelope tracking to average power tracking |
US8829993B2 (en) | 2012-10-30 | 2014-09-09 | Eta Devices, Inc. | Linearization circuits and methods for multilevel power amplifier systems |
US9537456B2 (en) | 2012-10-30 | 2017-01-03 | Eta Devices, Inc. | Asymmetric multilevel backoff amplifier with radio-frequency splitter |
US9166536B2 (en) | 2012-10-30 | 2015-10-20 | Eta Devices, Inc. | Transmitter architecture and related methods |
US9627975B2 (en) | 2012-11-16 | 2017-04-18 | Qorvo Us, Inc. | Modulated power supply system and method with automatic transition between buck and boost modes |
US9281852B2 (en) * | 2013-01-04 | 2016-03-08 | Marvell World Trade Ltd. | Method and apparatus for calibrating time alignment |
US9300252B2 (en) | 2013-01-24 | 2016-03-29 | Rf Micro Devices, Inc. | Communications based adjustments of a parallel amplifier power supply |
US8824981B2 (en) * | 2013-01-31 | 2014-09-02 | Intel Mobile Communications GmbH | Recalibration of envelope tracking transfer function during active transmission |
US9178472B2 (en) | 2013-02-08 | 2015-11-03 | Rf Micro Devices, Inc. | Bi-directional power supply signal based linear amplifier |
US9203353B2 (en) | 2013-03-14 | 2015-12-01 | Rf Micro Devices, Inc. | Noise conversion gain limited RF power amplifier |
US9197162B2 (en) | 2013-03-14 | 2015-11-24 | Rf Micro Devices, Inc. | Envelope tracking power supply voltage dynamic range reduction |
US9729110B2 (en) * | 2013-03-27 | 2017-08-08 | Qualcomm Incorporated | Radio-frequency device calibration |
US9479118B2 (en) | 2013-04-16 | 2016-10-25 | Rf Micro Devices, Inc. | Dual instantaneous envelope tracking |
US9374005B2 (en) | 2013-08-13 | 2016-06-21 | Rf Micro Devices, Inc. | Expanded range DC-DC converter |
CN104581920B (en) * | 2013-10-25 | 2019-07-23 | 展讯通信(上海)有限公司 | A kind of multi channel signals emission system and launching technique |
US9231627B2 (en) * | 2013-11-06 | 2016-01-05 | Stmicroelectronics International N.V. | Adaptive ISO-Gain pre-distortion for an RF power amplifier operating in envelope tracking |
US9172330B2 (en) * | 2013-12-02 | 2015-10-27 | Futurewei Technologies, Inc. | Nonlinear load pre-distortion for open loop envelope tracking |
US9794006B2 (en) * | 2014-05-08 | 2017-10-17 | Telefonaktiebolaget Lm Ericsson (Publ) | Envelope tracking RF transmitter calibration |
US9614476B2 (en) | 2014-07-01 | 2017-04-04 | Qorvo Us, Inc. | Group delay calibration of RF envelope tracking |
US9768731B2 (en) | 2014-07-23 | 2017-09-19 | Eta Devices, Inc. | Linearity and noise improvement for multilevel power amplifier systems using multi-pulse drain transitions |
US9979421B2 (en) | 2015-03-02 | 2018-05-22 | Eta Devices, Inc. | Digital pre-distortion (DPD) training and calibration system and related techniques |
US9912297B2 (en) | 2015-07-01 | 2018-03-06 | Qorvo Us, Inc. | Envelope tracking power converter circuitry |
US9948240B2 (en) | 2015-07-01 | 2018-04-17 | Qorvo Us, Inc. | Dual-output asynchronous power converter circuitry |
US9973147B2 (en) | 2016-05-10 | 2018-05-15 | Qorvo Us, Inc. | Envelope tracking power management circuit |
US9991913B1 (en) | 2016-12-07 | 2018-06-05 | Intel IP Corporation | Discrete levels envelope tracking |
US10181826B2 (en) | 2017-04-25 | 2019-01-15 | Qorvo Us, Inc. | Envelope tracking amplifier circuit |
US10158329B1 (en) | 2017-07-17 | 2018-12-18 | Qorvo Us, Inc. | Envelope tracking power amplifier circuit |
US10284412B2 (en) | 2017-07-17 | 2019-05-07 | Qorvo Us, Inc. | Voltage memory digital pre-distortion circuit |
US10158330B1 (en) | 2017-07-17 | 2018-12-18 | Qorvo Us, Inc. | Multi-mode envelope tracking amplifier circuit |
US10326490B2 (en) | 2017-08-31 | 2019-06-18 | Qorvo Us, Inc. | Multi radio access technology power management circuit |
US10530305B2 (en) | 2017-10-06 | 2020-01-07 | Qorvo Us, Inc. | Nonlinear bandwidth compression circuitry |
US10439557B2 (en) | 2018-01-15 | 2019-10-08 | Qorvo Us, Inc. | Envelope tracking power management circuit |
US10637408B2 (en) | 2018-01-18 | 2020-04-28 | Qorvo Us, Inc. | Envelope tracking voltage tracker circuit and related power management circuit |
US10742170B2 (en) | 2018-02-01 | 2020-08-11 | Qorvo Us, Inc. | Envelope tracking circuit and related power amplifier system |
US10476437B2 (en) | 2018-03-15 | 2019-11-12 | Qorvo Us, Inc. | Multimode voltage tracker circuit |
US10944365B2 (en) | 2018-06-28 | 2021-03-09 | Qorvo Us, Inc. | Envelope tracking amplifier circuit |
US11088618B2 (en) | 2018-09-05 | 2021-08-10 | Qorvo Us, Inc. | PWM DC-DC converter with linear voltage regulator for DC assist |
US10911001B2 (en) | 2018-10-02 | 2021-02-02 | Qorvo Us, Inc. | Envelope tracking amplifier circuit |
US10938351B2 (en) | 2018-10-31 | 2021-03-02 | Qorvo Us, Inc. | Envelope tracking system |
US10985702B2 (en) | 2018-10-31 | 2021-04-20 | Qorvo Us, Inc. | Envelope tracking system |
US11018638B2 (en) | 2018-10-31 | 2021-05-25 | Qorvo Us, Inc. | Multimode envelope tracking circuit and related apparatus |
US10680556B2 (en) | 2018-11-05 | 2020-06-09 | Qorvo Us, Inc. | Radio frequency front-end circuit |
US11031909B2 (en) | 2018-12-04 | 2021-06-08 | Qorvo Us, Inc. | Group delay optimization circuit and related apparatus |
US11082007B2 (en) | 2018-12-19 | 2021-08-03 | Qorvo Us, Inc. | Envelope tracking integrated circuit and related apparatus |
US11146213B2 (en) | 2019-01-15 | 2021-10-12 | Qorvo Us, Inc. | Multi-radio access technology envelope tracking amplifier apparatus |
US10998859B2 (en) | 2019-02-07 | 2021-05-04 | Qorvo Us, Inc. | Dual-input envelope tracking integrated circuit and related apparatus |
US11025458B2 (en) | 2019-02-07 | 2021-06-01 | Qorvo Us, Inc. | Adaptive frequency equalizer for wide modulation bandwidth envelope tracking |
US11233481B2 (en) | 2019-02-18 | 2022-01-25 | Qorvo Us, Inc. | Modulated power apparatus |
US11374482B2 (en) | 2019-04-02 | 2022-06-28 | Qorvo Us, Inc. | Dual-modulation power management circuit |
US11082009B2 (en) | 2019-04-12 | 2021-08-03 | Qorvo Us, Inc. | Envelope tracking power amplifier apparatus |
US11018627B2 (en) | 2019-04-17 | 2021-05-25 | Qorvo Us, Inc. | Multi-bandwidth envelope tracking integrated circuit and related apparatus |
US11424719B2 (en) | 2019-04-18 | 2022-08-23 | Qorvo Us, Inc. | Multi-bandwidth envelope tracking integrated circuit |
US11031911B2 (en) | 2019-05-02 | 2021-06-08 | Qorvo Us, Inc. | Envelope tracking integrated circuit and related apparatus |
US11349436B2 (en) | 2019-05-30 | 2022-05-31 | Qorvo Us, Inc. | Envelope tracking integrated circuit |
US11539289B2 (en) | 2019-08-02 | 2022-12-27 | Qorvo Us, Inc. | Multi-level charge pump circuit |
US11309922B2 (en) | 2019-12-13 | 2022-04-19 | Qorvo Us, Inc. | Multi-mode power management integrated circuit in a small formfactor wireless apparatus |
US11349513B2 (en) | 2019-12-20 | 2022-05-31 | Qorvo Us, Inc. | Envelope tracking system |
CN113132279A (en) * | 2019-12-30 | 2021-07-16 | 中兴通讯股份有限公司 | Pre-distortion processing method, device, equipment and storage medium |
US11539330B2 (en) | 2020-01-17 | 2022-12-27 | Qorvo Us, Inc. | Envelope tracking integrated circuit supporting multiple types of power amplifiers |
US11716057B2 (en) | 2020-01-28 | 2023-08-01 | Qorvo Us, Inc. | Envelope tracking circuitry |
US11728774B2 (en) | 2020-02-26 | 2023-08-15 | Qorvo Us, Inc. | Average power tracking power management integrated circuit |
US11196392B2 (en) | 2020-03-30 | 2021-12-07 | Qorvo Us, Inc. | Device and device protection system |
US11588449B2 (en) | 2020-09-25 | 2023-02-21 | Qorvo Us, Inc. | Envelope tracking power amplifier apparatus |
US11728796B2 (en) | 2020-10-14 | 2023-08-15 | Qorvo Us, Inc. | Inverted group delay circuit |
US11909385B2 (en) | 2020-10-19 | 2024-02-20 | Qorvo Us, Inc. | Fast-switching power management circuit and related apparatus |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6141541A (en) * | 1997-12-31 | 2000-10-31 | Motorola, Inc. | Method, device, phone and base station for providing envelope-following for variable envelope radio frequency signals |
US6160449A (en) * | 1999-07-22 | 2000-12-12 | Motorola, Inc. | Power amplifying circuit with load adjust for control of adjacent and alternate channel power |
US6240278B1 (en) * | 1998-07-30 | 2001-05-29 | Motorola, Inc. | Scalar cost function based predistortion linearizing device, method, phone and basestation |
US20030198300A1 (en) * | 2002-04-18 | 2003-10-23 | Nokia Corporation | Waveforms for envelope tracking transmitter |
US6646501B1 (en) * | 2002-06-25 | 2003-11-11 | Nortel Networks Limited | Power amplifier configuration |
US6788151B2 (en) * | 2002-02-06 | 2004-09-07 | Lucent Technologies Inc. | Variable output power supply |
US6794931B2 (en) * | 2000-02-25 | 2004-09-21 | Andrew Corporation | Switched amplifier |
US6853246B2 (en) * | 2002-04-18 | 2005-02-08 | Agere Systems Inc. | Adaptive predistortion system and a method of adaptively predistorting a signal |
US7023273B2 (en) * | 2003-10-06 | 2006-04-04 | Andrew Corporation | Architecture and implementation methods of digital predistortion circuitry |
US7043213B2 (en) * | 2003-06-24 | 2006-05-09 | Northrop Grumman Corporation | Multi-mode amplifier system |
US7058369B1 (en) * | 2001-11-21 | 2006-06-06 | Pmc-Sierra Inc. | Constant gain digital predistortion controller for linearization of non-linear amplifiers |
US7062236B2 (en) * | 2000-12-22 | 2006-06-13 | Nokia Corporation | Transmitter circuits |
US7183847B2 (en) * | 2004-01-28 | 2007-02-27 | Ntt Docomo, Inc. | Multi-band look-up table type predistorter |
US7339426B2 (en) * | 2004-03-19 | 2008-03-04 | Powerwave Technologies, Inc. | High efficiency linear amplifier employing dynamically controlled back off |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5420536A (en) | 1993-03-16 | 1995-05-30 | Victoria University Of Technology | Linearized power amplifier |
GB2345212B (en) | 1997-12-31 | 2000-11-29 | Motorola Inc | Device having a tracking power converter for providing a linear power amplifier |
-
2005
- 2005-03-07 US US11/073,535 patent/US20060199553A1/en not_active Abandoned
-
2008
- 2008-10-24 US US12/257,944 patent/US7715811B2/en not_active Expired - Fee Related
Patent Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6141541A (en) * | 1997-12-31 | 2000-10-31 | Motorola, Inc. | Method, device, phone and base station for providing envelope-following for variable envelope radio frequency signals |
US6240278B1 (en) * | 1998-07-30 | 2001-05-29 | Motorola, Inc. | Scalar cost function based predistortion linearizing device, method, phone and basestation |
US6160449A (en) * | 1999-07-22 | 2000-12-12 | Motorola, Inc. | Power amplifying circuit with load adjust for control of adjacent and alternate channel power |
US6794931B2 (en) * | 2000-02-25 | 2004-09-21 | Andrew Corporation | Switched amplifier |
US7062236B2 (en) * | 2000-12-22 | 2006-06-13 | Nokia Corporation | Transmitter circuits |
US7200367B1 (en) * | 2001-11-21 | 2007-04-03 | Pmc-Sierra, Inc. | Constant gain digital predistortion controller for linearization of non-linear amplifiers |
US7058369B1 (en) * | 2001-11-21 | 2006-06-06 | Pmc-Sierra Inc. | Constant gain digital predistortion controller for linearization of non-linear amplifiers |
US6788151B2 (en) * | 2002-02-06 | 2004-09-07 | Lucent Technologies Inc. | Variable output power supply |
US6853246B2 (en) * | 2002-04-18 | 2005-02-08 | Agere Systems Inc. | Adaptive predistortion system and a method of adaptively predistorting a signal |
US20030198300A1 (en) * | 2002-04-18 | 2003-10-23 | Nokia Corporation | Waveforms for envelope tracking transmitter |
US6774719B1 (en) * | 2002-06-25 | 2004-08-10 | Nortel Networks Limited | Power amplifier configuration |
US6646501B1 (en) * | 2002-06-25 | 2003-11-11 | Nortel Networks Limited | Power amplifier configuration |
US7043213B2 (en) * | 2003-06-24 | 2006-05-09 | Northrop Grumman Corporation | Multi-mode amplifier system |
US7023273B2 (en) * | 2003-10-06 | 2006-04-04 | Andrew Corporation | Architecture and implementation methods of digital predistortion circuitry |
US7183847B2 (en) * | 2004-01-28 | 2007-02-27 | Ntt Docomo, Inc. | Multi-band look-up table type predistorter |
US7339426B2 (en) * | 2004-03-19 | 2008-03-04 | Powerwave Technologies, Inc. | High efficiency linear amplifier employing dynamically controlled back off |
Cited By (52)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070178860A1 (en) * | 2006-01-27 | 2007-08-02 | Sehat Sutardja | Variable power adaptive transmitter |
US7761066B2 (en) | 2006-01-27 | 2010-07-20 | Marvell World Trade Ltd. | Variable power adaptive transmitter |
US7835710B2 (en) * | 2006-01-27 | 2010-11-16 | Marvell World Trade Ltd. | Variable power adaptive transmitter |
US20070178854A1 (en) * | 2006-01-27 | 2007-08-02 | Sehat Sutardja | Variable power adaptive transmitter |
US9166471B1 (en) | 2009-03-13 | 2015-10-20 | Rf Micro Devices, Inc. | 3D frequency dithering for DC-to-DC converters used in multi-mode cellular transmitters |
EP2306638A1 (en) * | 2009-09-30 | 2011-04-06 | Alcatel Lucent | Envelope tracking amplifier arrangement |
US9197182B2 (en) | 2010-02-01 | 2015-11-24 | Rf Micro Devices, Inc. | Envelope power supply calibration of a multi-mode radio frequency power amplifier |
US9031522B2 (en) | 2010-02-01 | 2015-05-12 | Rf Micro Devices, Inc. | Envelope power supply calibration of a multi-mode radio frequency power amplifier |
US9020452B2 (en) | 2010-02-01 | 2015-04-28 | Rf Micro Devices, Inc. | Envelope power supply calibration of a multi-mode radio frequency power amplifier |
US8983409B2 (en) | 2010-04-19 | 2015-03-17 | Rf Micro Devices, Inc. | Auto configurable 2/3 wire serial interface |
US9214865B2 (en) | 2010-04-20 | 2015-12-15 | Rf Micro Devices, Inc. | Voltage compatible charge pump buck and buck power supplies |
US9553550B2 (en) | 2010-04-20 | 2017-01-24 | Qorvo Us, Inc. | Multiband RF switch ground isolation |
US9900204B2 (en) | 2010-04-20 | 2018-02-20 | Qorvo Us, Inc. | Multiple functional equivalence digital communications interface |
US9722492B2 (en) | 2010-04-20 | 2017-08-01 | Qorvo Us, Inc. | Direct current (DC)-DC converter having a multi-stage output filter |
US8913967B2 (en) | 2010-04-20 | 2014-12-16 | Rf Micro Devices, Inc. | Feedback based buck timing of a direct current (DC)-DC converter |
US9577590B2 (en) | 2010-04-20 | 2017-02-21 | Qorvo Us, Inc. | Dual inductive element charge pump buck and buck power supplies |
US8942651B2 (en) | 2010-04-20 | 2015-01-27 | Rf Micro Devices, Inc. | Cascaded converged power amplifier |
US8942650B2 (en) | 2010-04-20 | 2015-01-27 | Rf Micro Devices, Inc. | RF PA linearity requirements based converter operating mode selection |
US8947157B2 (en) | 2010-04-20 | 2015-02-03 | Rf Micro Devices, Inc. | Voltage multiplier charge pump buck |
US8958763B2 (en) | 2010-04-20 | 2015-02-17 | Rf Micro Devices, Inc. | PA bias power supply undershoot compensation |
US8983407B2 (en) | 2010-04-20 | 2015-03-17 | Rf Micro Devices, Inc. | Selectable PA bias temperature compensation circuitry |
US9077405B2 (en) | 2010-04-20 | 2015-07-07 | Rf Micro Devices, Inc. | High efficiency path based power amplifier circuitry |
US8983410B2 (en) | 2010-04-20 | 2015-03-17 | Rf Micro Devices, Inc. | Configurable 2-wire/3-wire serial communications interface |
US8989685B2 (en) | 2010-04-20 | 2015-03-24 | Rf Micro Devices, Inc. | Look-up table based configuration of multi-mode multi-band radio frequency power amplifier circuitry |
US9008597B2 (en) | 2010-04-20 | 2015-04-14 | Rf Micro Devices, Inc. | Direct current (DC)-DC converter having a multi-stage output filter |
US9362825B2 (en) | 2010-04-20 | 2016-06-07 | Rf Micro Devices, Inc. | Look-up table based configuration of a DC-DC converter |
US9214900B2 (en) | 2010-04-20 | 2015-12-15 | Rf Micro Devices, Inc. | Interference reduction between RF communications bands |
US9030256B2 (en) | 2010-04-20 | 2015-05-12 | Rf Micro Devices, Inc. | Overlay class F choke |
US9048787B2 (en) | 2010-04-20 | 2015-06-02 | Rf Micro Devices, Inc. | Combined RF detector and RF attenuator with concurrent outputs |
US9184701B2 (en) | 2010-04-20 | 2015-11-10 | Rf Micro Devices, Inc. | Snubber for a direct current (DC)-DC converter |
US20110260790A1 (en) * | 2010-04-22 | 2011-10-27 | Samsung Electronics Co., Ltd. | Dual time alignment architecture for transmitters using eer/et amplifiers and others |
US9099966B2 (en) * | 2010-04-22 | 2015-08-04 | Samsung Electronics Co., Ltd. | Dual time alignment architecture for transmitters using EER/ET amplifiers and others |
US8483633B2 (en) | 2010-07-23 | 2013-07-09 | Motorola Solutions, Inc. | Method and apparatus for alarming in a power supply modulated system |
US8417199B2 (en) * | 2010-07-23 | 2013-04-09 | Motorola Solutions, Inc. | Method and apparatus for improving efficiency in a power supply modulated system |
US20120021695A1 (en) * | 2010-07-23 | 2012-01-26 | Motorola, Inc. | Method and Apparatus for Improving Efficiency in a Power Supply Modulated System |
WO2012114217A1 (en) * | 2011-02-22 | 2012-08-30 | Koninklijke Philips Electronics N.V. | Mri rf power amplifier with modulated power supply |
US9066368B2 (en) | 2011-06-08 | 2015-06-23 | Broadcom Corporation | Method of calibrating the delay of an envelope tracking signal |
WO2012170831A1 (en) * | 2011-06-08 | 2012-12-13 | Broadcom Corporation | Method of calibrating the delay of an envelope tracking signal |
US9065505B2 (en) * | 2012-01-31 | 2015-06-23 | Rf Micro Devices, Inc. | Optimal switching frequency for envelope tracking power supply |
US20130194979A1 (en) * | 2012-01-31 | 2013-08-01 | Rf Micro Devices, Inc. | Optimal switching frequency for envelope tracking power supply |
KR20150040787A (en) * | 2012-03-04 | 2015-04-15 | 퀀탄스, 인코포레이티드 | Envelope tracking power amplifier system with delay calibration |
CN104620509A (en) * | 2012-03-04 | 2015-05-13 | 匡坦斯公司 | Envelope tracking power amplifier system with delay calibration |
US9106293B2 (en) | 2012-03-04 | 2015-08-11 | Quantance, Inc. | Envelope tracking power amplifier system with delay calibration |
US9712114B2 (en) | 2012-03-04 | 2017-07-18 | Quantance, Inc. | Systems and methods for delay calibration in power amplifier systems |
WO2013134026A3 (en) * | 2012-03-04 | 2014-12-11 | Quantance, Inc. | Envelope tracking power amplifier system with delay calibration |
CN107171645A (en) * | 2012-03-04 | 2017-09-15 | 匡坦斯公司 | Power amplifier system and delay calibration method |
US8718579B2 (en) | 2012-03-04 | 2014-05-06 | Quantance, Inc. | Envelope tracking power amplifier system with delay calibration |
KR102037551B1 (en) | 2012-03-04 | 2019-10-28 | 퀀탄스, 인코포레이티드 | Envelope tracking power amplifier system with delay calibration |
US9794884B2 (en) | 2013-03-14 | 2017-10-17 | Quantance, Inc. | Envelope tracking system with adjustment for noise |
US9762184B2 (en) | 2013-03-15 | 2017-09-12 | Quantance, Inc. | Envelope tracking system with internal power amplifier characterization |
CN106301239A (en) * | 2013-07-18 | 2017-01-04 | 英特尔移动通信有限责任公司 | Utilize the system and method for self adaptation envelope-tracking |
CN104300915A (en) * | 2013-07-18 | 2015-01-21 | 英特尔移动通信有限责任公司 | Systems and methods utilizing adaptive envelope tracking |
Also Published As
Publication number | Publication date |
---|---|
US20090045872A1 (en) | 2009-02-19 |
US7715811B2 (en) | 2010-05-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7715811B2 (en) | Integrated transceiver with envelope tracking | |
US7706467B2 (en) | Transmitter with an envelope tracking power amplifier utilizing digital predistortion of the signal envelope | |
US8472897B1 (en) | Power amplifier predistortion methods and apparatus | |
US10148296B2 (en) | Transmitter, communication unit and methods for limiting spectral re-growth | |
US8433263B2 (en) | Wireless communication unit, integrated circuit and method of power control of a power amplifier therefor | |
US8665018B2 (en) | Integrated circuit, wireless communication unit and method for a differential interface for an envelope tracking signal | |
US7561636B2 (en) | Digital predistortion apparatus and method in power amplifier | |
US8224266B2 (en) | Power amplifier predistortion methods and apparatus using envelope and phase detector | |
JP3447266B2 (en) | Apparatus and method for power amplification linearization in mobile communication system | |
EP2143209B1 (en) | Digital hybrid mode power amplifier system | |
US7831221B2 (en) | Predistortion system and amplifier for addressing group delay modulation | |
EP1011192A2 (en) | A linear amplifier arrangement | |
US20090085658A1 (en) | Analog power amplifier predistortion methods and apparatus | |
KR20050012835A (en) | Improved power amplifier configuration | |
WO2001080471A2 (en) | Transmitter linearization using fast predistortion | |
GB2438749A (en) | An EER transmitter with linearizing feedback | |
WO2008019287A2 (en) | Replica linearized power amplifier | |
KR20060023605A (en) | Adjusting the amplitude and phase characteristics of transmitter generated wireless communication signals in response to base station transmit power control signals and known transmitter amplifier characteristics | |
EP1518320B1 (en) | Efficient generation of radio frequency currents | |
CN101594324B (en) | Method for generating pre-distorted signals | |
US9088472B1 (en) | System for compensating for I/Q impairments in wireless communication system | |
US11251753B2 (en) | Envelope tracking supply modulator with zero peaking and associated envelope tracking calibration method and system | |
KR20190049344A (en) | Method and Apparatus for Digital Pre-Distortion |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ANDREW CORPORATION, ILLINOIS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KENINGTON, PETER BLAKESBOROUGH;REEL/FRAME:017113/0834 Effective date: 20050304 |
|
AS | Assignment |
Owner name: BANK OF AMERICA, N.A., AS ADMINISTRATIVE AGENT, CA Free format text: SECURITY AGREEMENT;ASSIGNORS:COMMSCOPE, INC. OF NORTH CAROLINA;ALLEN TELECOM, LLC;ANDREW CORPORATION;REEL/FRAME:020362/0241 Effective date: 20071227 Owner name: BANK OF AMERICA, N.A., AS ADMINISTRATIVE AGENT,CAL Free format text: SECURITY AGREEMENT;ASSIGNORS:COMMSCOPE, INC. OF NORTH CAROLINA;ALLEN TELECOM, LLC;ANDREW CORPORATION;REEL/FRAME:020362/0241 Effective date: 20071227 |
|
AS | Assignment |
Owner name: ANDREW LLC, NORTH CAROLINA Free format text: CHANGE OF NAME;ASSIGNOR:ANDREW CORPORATION;REEL/FRAME:021763/0976 Effective date: 20080827 Owner name: ANDREW LLC,NORTH CAROLINA Free format text: CHANGE OF NAME;ASSIGNOR:ANDREW CORPORATION;REEL/FRAME:021763/0976 Effective date: 20080827 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: ALLEN TELECOM LLC, NORTH CAROLINA Free format text: PATENT RELEASE;ASSIGNOR:BANK OF AMERICA, N.A., AS ADMINISTRATIVE AGENT;REEL/FRAME:026039/0005 Effective date: 20110114 Owner name: COMMSCOPE, INC. OF NORTH CAROLINA, NORTH CAROLINA Free format text: PATENT RELEASE;ASSIGNOR:BANK OF AMERICA, N.A., AS ADMINISTRATIVE AGENT;REEL/FRAME:026039/0005 Effective date: 20110114 Owner name: ANDREW LLC (F/K/A ANDREW CORPORATION), NORTH CAROL Free format text: PATENT RELEASE;ASSIGNOR:BANK OF AMERICA, N.A., AS ADMINISTRATIVE AGENT;REEL/FRAME:026039/0005 Effective date: 20110114 |