WO2018109927A1 - Émetteur à correction aval et système d'émission - Google Patents

Émetteur à correction aval et système d'émission Download PDF

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Publication number
WO2018109927A1
WO2018109927A1 PCT/JP2016/087564 JP2016087564W WO2018109927A1 WO 2018109927 A1 WO2018109927 A1 WO 2018109927A1 JP 2016087564 W JP2016087564 W JP 2016087564W WO 2018109927 A1 WO2018109927 A1 WO 2018109927A1
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Prior art keywords
signal
amplifier
control
control circuit
feedforward
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PCT/JP2016/087564
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English (en)
Japanese (ja)
Inventor
一二三 能登
田島　賢一
浩行 圷
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三菱電機株式会社
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Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2017534364A priority Critical patent/JP6242548B1/ja
Priority to PCT/JP2016/087564 priority patent/WO2018109927A1/fr
Publication of WO2018109927A1 publication Critical patent/WO2018109927A1/fr

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/32—Modifications of amplifiers to reduce non-linear distortion
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
    • H03F3/24—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers of transmitter output stages

Definitions

  • the present invention relates to a technique for compensating nonlinearity of input / output characteristics of an amplifier that amplifies the power of a modulated wave signal of a plurality of channels, and more particularly, to an input of a common amplification configuration that amplifies the power of the modulated wave signals of a plurality of channels at once.
  • the present invention relates to a technique for compensating for nonlinearity of output characteristics.
  • the amplifier causes distortion (hereinafter also referred to as “nonlinear distortion”) in the output signal waveform when the input signal is amplified due to the nonlinearity.
  • nonlinear distortion distortion
  • a distortion compensation circuit is used to compensate for distortion generated in an amplifier.
  • the types of distortion compensation circuits are broadly classified into three types: negative feedback type, feed forward type, and predistortion type.
  • Negative feedback type amplifiers are mainly used for narrowband modulated wave signals, and feedforward and predistortion type amplifiers, for example, base stations that amplify relatively wideband modulated wave signals. It is used as an amplifier.
  • feedforward and predistortion type amplifiers for example, base stations that amplify relatively wideband modulated wave signals. It is used as an amplifier.
  • a predistortion type amplifier a digital predistortion technique using digital signal processing is often incorporated. In recent years, digital predistortion capable of feeding back information on a modulated wave signal generated by a modem has been widely adopted in base stations.
  • a feedforward amplifier is disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-013946.
  • a plurality of amplifiers are used to individually amplify the plurality of channel transmission signals, and a plurality of channel transmission signals are combined to form one combined signal.
  • the feedforward amplifier can reduce nonlinear distortion with high efficiency when the level of the synthesized signal is substantially constant.
  • the feedforward amplifier cannot always operate in a state suitable for that level or frequency band. Or the distortion compensation amount may be deteriorated.
  • an object of the present invention is to provide a feedforward transmitter and a transmission system having a common amplification configuration capable of amplifying and transmitting a transmission signal of a plurality of channels with high efficiency.
  • a feedforward transmitter includes: a plurality of input ports to which a plurality of channels of transmission signals are respectively input; a signal synthesizer that combines the plurality of channels of transmission signals; A feedforward amplifier that amplifies the power of the feedforward amplifier; a control circuit that generates an operation state that determines an operating state of at least one circuit element that constitutes the feedforward amplifier; and a control circuit that supplies the control signal to the feedforward amplifier; And a signal detection unit that detects a transmission signal input to the input port of the output signal and outputs a detection signal indicating the detection result to the control circuit, wherein the control circuit controls one or more controls based on the detection signal. Determining a parameter and generating the control signal using the control parameter or parameters. To.
  • FIG. 1 shows schematic structure of the transmission system of Embodiment 1 which concerns on this invention.
  • 2A and 2B are diagrams illustrating examples of the contents of the reference table in the control circuit according to the first embodiment.
  • 3A to 3D are schematic diagrams for explaining one of the operation states (state 1) of the feedforward amplifier according to the first embodiment.
  • 4A to 4D are schematic diagrams for explaining one of the operation states (state 2) of the feedforward amplifier according to the first embodiment.
  • 5A to 5D are schematic diagrams for explaining one of the operation states (state 3) of the feedforward amplifier according to the first embodiment.
  • 6 is a graph showing an example of distortion characteristics of a feedforward amplifier in states 1 to 3.
  • FIG. 7A and 7B are graphs showing the relationship between the number of operating modems and power consumption in states 1 to 3.
  • FIG. 3 is a flowchart illustrating an example of a processing procedure of a control circuit according to the first embodiment. It is a figure which shows schematic structure of the transmission system of Embodiment 2 which concerns on this invention.
  • 6 is a diagram illustrating a configuration example of a phase circuit according to a second embodiment.
  • FIG. FIG. 10 is a diagram illustrating another configuration example of the phase circuit according to the second embodiment.
  • FIG. 10 is a diagram schematically showing an example of the contents of a reference table in the control circuit of the second embodiment.
  • 13A to 13D are schematic diagrams for explaining one of the operation states (state 1) of the feedforward amplifier according to the second embodiment.
  • 14A to 14D are schematic diagrams for explaining one of the operation states (state 2) of the feedforward amplifier according to the second embodiment.
  • 15A to 15D are schematic diagrams for explaining one of the operation states (state 3) of the feedforward amplifier according to the second embodiment.
  • 16A to 16D are schematic diagrams for explaining one of the operation states (state 4) of the feedforward amplifier according to the second embodiment.
  • FIGS. 17A to 17D are schematic diagrams for explaining one of the operation states (state 5) of the feedforward amplifier according to the second embodiment.
  • 6 is a flowchart illustrating an example of a control procedure of the control circuit according to the second embodiment. 6 is a graph showing a correspondence relationship between a phase deviation and an amplitude deviation according to the second embodiment.
  • 20A and 20B are graphs showing examples of group delay time characteristics according to the second embodiment.
  • 6 is a graph showing an example of an output power spectrum of the FF amplifier according to the second embodiment. It is a figure which shows schematic structure of the transmission system of Embodiment 3 which concerns on this invention.
  • FIG. 1 is a diagram showing a schematic configuration of a transmission system according to Embodiment 1 of the present invention.
  • the transmission system of the present embodiment includes a modulator 10 capable of outputting n-channel (n is an integer of 4 or more) modulated wave signals in parallel as n-channel transmission RF signals, and these n-channel transmission RF signals.
  • a feed forward transmitter (FF transmitter) 20 having a common amplification configuration capable of amplifying the signals collectively.
  • the FF transmitter 20 combines n input ports 21 1 to 21 n to which n-channel transmission RF signals are respectively input, and a power combiner (RF that combines the n-channel transmission RF signals and outputs a combined signal.
  • a signal power combiner) 22 a feedforward amplifier (FF amplifier) 25 that amplifies the power of the combined signal and compensates for nonlinear distortion, and an output port 29 that outputs the amplified signal input from the FF amplifier 25 to the outside.
  • the control circuit 26 that generates the control signal CS that individually determines the operation state of the circuit elements 32, 33, 34, 41, 52, 53, and 54 constituting the FF amplifier 25 and the input ports 21 1 to 21 n are input.
  • Power detectors 23 1 to 23 n for detecting the transmitted RF signal.
  • the power detectors 23 1 to 23 n (hereinafter also referred to as “detectors 23 1 to 23 n ”) are signals D 1 to D that indicate the detection levels of the transmission RF signals respectively input to the input ports 21 1 to 21 n. D n is supplied to the control circuit 26 as the detection signal DS. These power detectors 23 1 to 23 n constitute the signal detector of the present embodiment.
  • the control circuit 26 determines control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge based on the detection signal DS, and these control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge. Has a function of generating the control signal CS.
  • the modulator 10 is composed of n modems M 1 to M n . These modems M 1 to M n generate n-channel modulated wave signals having different frequency bands, and output these n-channel modulated wave signals to the FF transmitter 20 as n-channel RF transmission signals.
  • the transmission system according to the present embodiment has a common amplification configuration that collectively amplifies four or more n-channel transmission RF signals, but the present invention is not limited to this. It is possible to appropriately change the common amplification configuration of the present embodiment so as to amplify 2-channel or 3-channel transmission RF signals all together.
  • the FF amplifier 25 includes a coupler 31, a variable attenuator 32, a variable phase shifter 33, a main amplifier 34, a coupler 40, a variable attenuator 41, as circuit element groups constituting a distortion extraction loop.
  • a delay line 35 and a coupler 42 are provided. Nonlinear distortion components generated in the main amplifier 34 are extracted by this distortion extraction loop.
  • the FF amplifier 25 includes a coupler 40, a variable attenuator 41, a coupler 42, a variable attenuator 52, a variable phase shifter 53, an error amplifier 54, a delay line 55, and a coupler 56 as circuit element groups constituting a distortion elimination loop. have.
  • variable attenuator 52, the variable phase shifter 53, and the error amplifier 54 adjust the amplitude and phase of the extracted nonlinear distortion component.
  • the coupler 56 synthesizes the amplified signal transmitted from the main amplifier 34 via the delay line 55 and the nonlinear distortion component transmitted from the error amplifier 54 in mutually opposite phases, thereby including the amplified signal in the amplified signal.
  • the nonlinear distortion component to be reduced can be reduced.
  • the configuration of the FF amplifier 25 is an example, and the feedforward amplifier of the present invention is not limited to this configuration.
  • the control parameter Ca indicates a signal value for controlling the signal attenuation amount in the variable attenuator 32
  • the control parameter Cb indicates a signal value for controlling the phase shift correction amount in the variable phase shifter 33
  • the control parameter Cc is variable.
  • the signal value for controlling the signal attenuation amount in the attenuator 41 is indicated.
  • the control parameter Cd indicates the signal value for controlling the signal attenuation amount in the variable attenuator 52.
  • the control parameter Ce is the phase shift correction in the variable phase shifter 53. Signal values that control the quantity are shown.
  • Each of the main amplifier 34 and the error amplifier 54 is configured by a field effect transistor (FET), but may be configured by using a bipolar transistor instead of the field effect transistor.
  • the control parameter Vdm indicates a control voltage for controlling the drain voltage (or collector voltage) of the main amplifier 34
  • Vgm indicates a control voltage for controlling the gate voltage (or base voltage) of the main amplifier 34.
  • the control circuit 26 can control the operation state (for example, operation grade or saturation power) of the main amplifier 34 by changing the control parameters Vdm and Vgm.
  • the control parameter Vde indicates a control voltage for controlling the drain voltage (or collector voltage) of the error amplifier 54
  • the control parameter Vge indicates a control voltage for controlling the gate voltage (or base voltage) of the error amplifier 54. Yes.
  • the control circuit 26 can control the operation state (for example, operation grade or saturation power) of the error amplifier 54 by changing the control parameters Vde and Vge.
  • the control circuit 26 Based on the detection signal DS, the control circuit 26 according to the present embodiment has the number of operating modems M 1 to M n , that is, the number of transmission RF signals input to the input ports 21 1 to 21 n (having power of a certain level or higher). The number of transmission RF signals) is estimated, and the control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge are determined according to the estimated value of the number using the reference table (TBL) 27. Can do.
  • TBL reference table
  • this modem M k when the k-th modem M k is operating, this modem M k outputs the transmission RF signal of the k-th channel, but when the modem M k stops operating, The modem M k does not output a transmission RF signal. For this reason, the number of operating modems M 1 to M n matches the number of transmission RF signals input to the input ports 21 1 to 21 n .
  • a value of “0” indicates that there is no input transmission RF signal, in other words, the corresponding modem is not operating.
  • a value of “1” indicates a case where the input transmission RF signal is present, in other words, a case where the corresponding modem is operating.
  • FIG. 2B shows control patterns PTN 1 to PTN 9 , the number of operating modems M 1 to M 8 (that is, the number of transmission RF signals input to the input ports 21 1 to 21 8 ), and four types of FF amplifiers 25.
  • FIG. 6 is a diagram illustrating a correspondence relationship between the states (“power off”, “state 1”, “state 2”, and “state 3”) in a table format.
  • the control circuit 26 selects “state 1” when 5 to 8 modems among the modems M 1 to M n are operating, and selects “state 2” when 3 to 4 modems are operating. And select “state 3” if one or two modems are operating.
  • state 2 the operation of the error amplifier 54 of the FF amplifier 25 is stopped, and only the main amplifier 34 operates.
  • the bias condition for the main amplifier 34 at this time is different from that in the state 1.
  • State 3 is a state in which the bias condition has been changed further than in state 2.
  • FIG. 3A, FIG. 3B, FIG. 3C, and FIG. 3D show the detection results D 1 to D 8 of the transmission RF signal in the “state 1”, the levels of these transmission RF signals, the contents of the control signal CS, and the FF amplifier 25 It is a figure which shows an operating state roughly, respectively.
  • FIG. 3D illustrates an outline of the signal levels S11 to S14 at each stage.
  • 4A, FIG. 4B, FIG. 4C and FIG. 4D show the detection results D 1 to D 8 of the transmission RF signal in the “state 2”, the levels of these transmission RF signals, the contents of the control signal CS, and the FF amplifier.
  • FIG. 25 is a diagram schematically showing 25 operation states.
  • FIG. 25 is a diagram schematically showing 25 operation states.
  • FIG. 4D illustrates an outline of the signal levels S21, S22, and S24 at each stage.
  • 5A, FIG. 5B, FIG. 5C, and FIG. 5D show the detection results D 1 to D 8 of the transmission RF signal in the “state 3”, the levels of these transmission RF signals, the contents of the control signal CS, and the FF amplifier.
  • FIG. 25 is a diagram schematically showing 25 operation states.
  • FIG. 5D illustrates an outline of signal levels S31, S32, and S34 at each stage.
  • the control circuit 26 controls the FF amplifier 25 so as to perform an operation suitable when the number of operation of the modems M 1 to M 8 is 5 to 8.
  • the control circuit 26 does not operate the error amplifier 54 by pinching off, and changes the gate voltage with the drain voltage of the main amplifier 34 being the same as in the state 1 to change the characteristics of the main amplifier 34 in the class A operation.
  • the characteristic is changed to a characteristic close to the characteristic.
  • State 3 is a state in which the drain voltage is further lowered from state 2 and the saturation power is lowered.
  • the reason why the gate voltage is changed when the operation state of the FF amplifier 25 shifts from the state 1 to the state 2 is that the main amplifier 34 of the FF amplifier 25 is normally operated with high efficiency. This is because the nonlinear distortion deteriorates when the main amplifier 34 is operated under the bias condition.
  • FIG. 6 is a graph showing an example of distortion characteristics of the FF amplifier 25 in the state 1, the state 2 and the state 3.
  • the horizontal axis indicates the output back-off (unit: dB) determined based on the saturated power when the number of operating modems M 1 to M 8 is 8, and the vertical axis indicates adjacent channel leakage.
  • the power ratio Adjacent Channel Leakage Ratio: ACLR
  • curves C1, C2, and C3 indicate distortion characteristics in the states 1, 2, and 3, respectively.
  • the input / output characteristics of the FF amplifier 25 depend on the total power of the transmission RF signal input from the modulator 10 and the PAPR (Peak-to-Average Power Ratio) of the modulation wave used. Change.
  • the state 1 is a state selected when 5 to 8 modems among the modems M 1 to M 8 are operating. In this state 1, the FF amplifier 25 is controlled so as to exhibit an original function as a feedforward amplifier (a function of a non-linear distortion compensation method for making input / output characteristics linear).
  • State 2 is a state selected when three or four modems among the modems M 1 to M 8 are operating.
  • the power is reduced by 3 dB compared to when eight modems operate.
  • the FF amplifier 25 operates so as to exhibit its original function as a feedforward amplifier, the error amplifier 54 system operates even though the distortion compensation amount is small. Become. Therefore, in the state 2, the control circuit 26 does not operate the system of the error amplifier 54 in the FF amplifier 25, but operates only the system of the main amplifier 34, thereby realizing reduction of power consumption.
  • the control circuit 26 adjusts the control voltage Vgm of the main amplifier 34 to operate the main amplifier 34 as a class AB amplifier in order to increase the efficiency of the FF amplifier 25.
  • the control circuit 26 adjusts the control voltage Vgm to operate the main amplifier 34 as a class A amplifier.
  • the linearity of the main amplifier 34 is improved.
  • the graph of FIG. 6 shows the relationship between the output back-off and the ACLR based on the saturated output when eight modems operate. According to this graph, the state 2 can satisfy the ACLR of ⁇ 50 dBc for the power reduction of 3 dB with respect to the state 1. Further, from the relationship between the number of operating modems M 1 to M 8 and the power consumption of the FF transmitter 20, the transition of the state 1 to the state 2 makes it possible to reduce the power consumption.
  • the state 3 is a state selected when one or two modems among the modems M 1 to M 8 are operating, and is a state in which the power of 3 dB is further reduced from the state 2.
  • the ACLR in state 2 met -50 dBc with 4 modems, so if a further 3 dB power reduction occurs, the ACLR will be overfilled. Therefore, the control circuit 26 reduces the saturation power of the main amplifier 34 by adjusting the control voltage Vdm, thereby realizing a reduction in power consumption.
  • State 3 versus State 2 can satisfy an ACLR of ⁇ 50 dBc for a 3 dB power reduction.
  • FIG. 7A is a graph illustrating an example of power consumption of the FF amplifier 25 in the state 1, the state 2 and the state 3.
  • the horizontal axis indicates the number of operating modems M 1 to M 8
  • the vertical axis indicates the power consumption (unit: watts) of the FF amplifier 25.
  • Solid lines P1, P2, and P3 indicate power consumption in states 1, 2, and 3, respectively.
  • FIG. 7B is a graph showing the transition of the power consumption Pa when the control circuit 26 controls the operation of the FF amplifier 25 using the table of FIG. 2B. As shown in FIG. 7B, the minimum power consumption is selected according to the number of modems M 1 to M 8 .
  • the control circuit 26 determines the control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, and Vge based on the estimated values of the operation numbers of the modems M 1 to M n . Instead, the control circuit 26 estimates the total power of the input RF signal from the detection signal DS, and determines the control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, and Vge according to the total power. Also good. In this case, the TBL 27 only needs to store the correspondence between the total power value and the state of the FF amplifier 25. The control circuit 26 uses this TBL 27 to select a state of the FF amplifier 25 suitable for the total power, and control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge for realizing the state. Can be determined.
  • FIG. 8 is a flowchart illustrating an example of a control procedure of the control circuit 26.
  • control circuit 26 estimates the number of operating modems M 1 to M n based on the outputs of power detectors 23 1 to 23 n (step ST11).
  • the control circuit 26 determines the state of the FF amplifier 25 based on the estimated number of operations (step ST12).
  • the control circuit 26 uses the TBL 27 to set the state (“power off”, “state 1”, “state 2” or “state 3”) of the FF amplifier 25 suitable for the estimated number of operations. )) Can be determined.
  • control circuit 26 determines the control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, and Vge based on the state determined in step ST12 (step ST13). Thereafter, the control circuit 26 generates a control signal CS based on these control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge, and supplies the control signal CS to the FF amplifier 25 to thereby generate an FF amplifier. 25 is controlled (step ST14). Thereafter, when the control is not terminated (NO in step ST15), the control circuit 26 executes steps ST11 to ST14 again. When receiving an end instruction from the outside or when a predetermined end condition is satisfied, the control circuit 26 ends the control (YES in step ST15).
  • the FF transmitter 20 combines the n-channel transmission signal supplied from the modulator 10 and outputs a combined signal, and the power of the combined signal. It has a common amplification configuration including the FF amplifier 25 to be amplified, and the level of the combined signal can be changed according to the transmission signal of the n channel.
  • the control circuit 26 determines the control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge based on the detection signal DS, and these control parameters Ca, Cb, Since the control signal CS is generated using Cc, Cd, Vdm, Vgm, Vde, and Vge, the FF amplifier 25 changes to an appropriate operation state designated by the control signal CS according to the change in the level of the synthesized signal. Transition is possible. Therefore, a common amplification configuration that can amplify the transmission signals of a plurality of channels with high efficiency is realized.
  • FIG. 9 is a diagram showing a schematic configuration of the transmission system according to the second embodiment of the present invention.
  • the transmission system according to the present embodiment includes a modulator 10 that supplies an n-channel transmission RF signal, and a feedforward transmitter (FF) that has a common amplification configuration that can amplify the n-channel transmission RF signals collectively.
  • Transmitter 20A Transmitter
  • the FF transmitter 20A includes input ports 21 1 to 21 n , a power combiner 22, and a feedforward amplifier (FF amplifier) 25A that amplifies the power of the combined signal output from the power combiner 22 and compensates for nonlinear distortion.
  • the FF transmitter 20A further detects the frequencies (frequency bands or center frequencies) ⁇ 1 to ⁇ n of the transmission RF signals input to the input ports 21 1 to 21 n , and signals F 1 to F indicating the detection results.
  • Frequency detectors 24 1 to 24 n that supply n to the control circuit 26A as a detection signal FS are provided.
  • the control circuit 26A Based on the detection signals DS and FS, the control circuit 26A generates a control signal CSa that individually determines the operation states of the circuit elements 32, 36, 34, 41, 52, 57, and 54 that constitute the FF amplifier 25A. By supplying the control signal CSa to the FF amplifier 25A, the operation state of the FF amplifier 25A can be controlled.
  • FIGS. 10 and 11 are diagrams showing configuration examples of the phase shift circuits 36 and 57 having a low-pass type matching circuit.
  • variable phase shifter 61 includes a variable phase shifter 61, a delay line 62, a capacitive element 63, a variable capacitive element 64, and a resistive element 65.
  • the variable phase shifter 61 is controlled by the control parameter Cb. That is, the phase shift correction amount in the variable phase shifter 33 is controlled by the control parameter Cb.
  • the variable capacitance element 64 can be composed of, for example, a varactor diode (variable capacitance diode).
  • the variable phase shifter 61 and the delay line 62 are connected in series between the variable attenuators 32 and 34.
  • One end of the capacitive element 63 is connected to one end of the delay line 62, and the other end of the capacitive element 63 is connected to one end of the variable capacitive element 64 and one end of the resistive element 65.
  • the other end of the variable capacitance element 64 is grounded.
  • a control voltage Vpm which is one of the control parameters supplied from the control circuit 26A, is applied to the other end of the resistance element 65.
  • the control circuit 26A changes the capacitance of the matching circuit (the delay line 62, the capacitive element 63, the variable capacitive element 64, and the resistive element 65) of the phase shift circuit 36 by changing the control voltage Vpm, thereby changing the phase shift circuit 36.
  • the frequency band of the input signal to can be changed.
  • the phase shift circuit 57 shown in FIG. 11 includes a variable phase shifter 71, a delay line 72, a capacitive element 73, a variable capacitive element 74, and a resistive element 75.
  • the variable phase shifter 71 is controlled by the control parameter Ce. That is, the phase shift correction amount in the variable phase shifter 71 is controlled by the control parameter Ce.
  • the variable capacitance element 74 can be composed of, for example, a varactor diode (variable capacitance diode).
  • the variable phase shifter 71 and the delay line 72 are connected in series between the variable attenuators 52 and 54.
  • One end of the capacitive element 73 is connected to one end of the delay line 72, and the other end of the capacitive element 73 is connected to one end of the variable capacitive element 74 and one end of the resistive element 75.
  • the other end of the variable capacitance element 74 is grounded.
  • a control voltage Vpe which is one of the control parameters supplied from the control circuit 26A, is applied to the other end of the resistance element 75.
  • the control circuit 26A changes the capacitance of the matching circuit (the delay line 72, the capacitive element 73, the variable capacitive element 74, and the resistive element 75) of the phase shift circuit 57 by changing the control voltage Vpe, thereby changing the phase shift circuit 57.
  • the frequency band of the input signal to can be changed.
  • the control circuit 26A determines the number of operating modems M 1 to M n , that is, the number of transmission RF signals input to the input ports 21 1 to 21 n (the number of transmission RF signals having power of a certain level or more). ), And based on the detection signal FS, it is determined whether or not a transmission RF signal in a specific frequency band (specific band) is input to the input ports 21 1 to 21 n . Then, the control circuit 26A uses the reference table (TBL) 27A to control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge, Vpm, Vpe can be determined.
  • TBL reference table
  • the TBL 27A can store, for example, the table shown in FIG. 2A and the table shown in FIG.
  • the control circuit 26A determines one pattern PTNk from among the control patterns PTN1 to PTN9 using the table of FIG. 2A, and then uses the table of FIG. 12 to select six states (“power off”). , “State 1”, “state 2”, “state 3”, “state 4”, and “state 5”), the state corresponding to the estimated value of the number of motions and the determination result can be selected.
  • the control circuit 26A selects “state 1” when 6 to 8 modems among the modems M 1 to M n are operating, and the 5 modems operate. If it is, select either “State 2” or “State 3”. If 3 to 4 modems are operating, select “State 4” and select 1 to 2 modems. If it is, select “state 5”, and if there is no operating modem, select the “power off” state.
  • “state 3” is selected.
  • “state 2” is selected when five modems operate and a transmission RF signal in a specific band is not input to any of the input ports 21 1 to 21 n .
  • the total power value of the input RF signal may be stored instead of the estimated value of the operation number of the modems M 1 to M n .
  • the control circuit 26A can use the TBL 27A to select the state of the FF amplifier 25A suitable for the total power.
  • FIG. 13A, FIG. 13B, FIG. 13C, and FIG. 13D show the detection results D 1 to D 8 of the transmission RF signal in the “state 1”, the level and total power (D all ) of these transmission RF signals, and the control signal CSa. It is a figure which shows roughly the content and the operation state of FF amplifier 25A, respectively.
  • FIG. 13D illustrates an outline of signal levels S41 to S44 at each stage. 14A, FIG. 14B, FIG. 14C, and FIG. 14D show the detection results D 1 to D 8 of the transmission RF signal in the “state 2”, the level and total power (D all ) of these transmission RF signals, and the control signal.
  • FIG. 14D illustrates an outline of signal levels S51 to S54 at each stage.
  • 15A, FIG. 15B, FIG. 15C, and FIG. 15D show the detection results D 1 to D 8 of the transmission RF signal in the “state 3”, the level and total power (D all ) of these transmission RF signals, and the control signal.
  • FIG. 15D illustrates an outline of signal levels S61 to S64 at each stage. 16A, FIG. 16B, FIG. 16C, and FIG.
  • FIG. 16D show detection results D 1 to D 8 of the transmission RF signal in the “state 4”, the level and total power (D all ) of these transmission RF signals, and the control signal. It is a figure which shows roughly the content of CSa, and the operating state of FF amplifier 25A, respectively.
  • FIG. 16D illustrates an outline of signal levels S71, S72, and S74 at each stage.
  • 17A, FIG. 17B, FIG. 17C, and FIG. 17D show the detection results D 1 to D 8 of the transmission RF signal in the “state 5”, the level and total power (D all ) of these transmission RF signals, and the control signal. It is a figure which shows roughly the content of CSa, and the operating state of FF amplifier 25A, respectively.
  • FIG. 17D illustrates an outline of signal levels S81, S82, and S84 at each stage.
  • FIG. 18 is a flowchart illustrating an example of a control procedure of the control circuit 26A.
  • control circuit 26A estimates the number of operating modems M 1 to M n based on the outputs of power detectors 23 1 to 23 n (step ST21).
  • the control circuit 26A determines the presence / absence of an input signal in a specific band based on the outputs of the frequency detectors 24 1 to 24 n (step ST22).
  • the control circuit 26A determines the state of the FF amplifier 25 based on the estimated number of operations and the determination result (step ST23).
  • the control circuit 26 uses the TBL 27A to set the state of the FF amplifier 25A (“power off”, “state 1”, “state 2”, “State 3", “State 4" or "State 5”) can be determined.
  • control circuit 26A determines the control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge, Vpm, Vpe based on the state determined in step ST23 (step ST24). Thereafter, the control circuit 26A generates a control signal CSa based on these control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge, Vpm, Vpe, and supplies this control signal CSa to the FF amplifier 25A. Thus, the operation of the FF amplifier 25A is controlled (step ST25). Thereafter, when the control is not ended (NO in step ST26), the control circuit 26 executes steps ST21 to ST25 again. When receiving an end instruction from the outside or when a predetermined end condition is satisfied, the control circuit 26A ends the control (YES in step ST26).
  • the transmission system combines the n-channel transmission signal supplied from the modulator 10 and outputs a combined signal, and amplifies the power of the combined signal. It has a common amplification configuration including the FF amplifier 25A, and the level or frequency band of the combined signal can be changed according to the transmission signal of the n channel. Even when one or both of the level and frequency band of the composite signal change, the control circuit 26A can control the control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vde, Vge, Vpm based on the detection signals DS, FS.
  • Vpe are determined, and the control signal CSa is generated using these control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge, Vpm, and Vpe.
  • the control signal CSa is generated using these control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge, Vpm, and Vpe.
  • control circuit 26A can control the frequency characteristics of the FF amplifier 25A (for example, characteristics related to the frequency of the group delay time) in accordance with the change in the frequency band of the synthesized signal. Compared to 1, finer adaptive control can be performed.
  • FIG. 19 is a graph showing an example of the relationship between the phase deviation, the amplitude deviation, and the distortion removal amount in the FF amplifier 25A.
  • the horizontal axis indicates the phase deviation (unit: deg)
  • the vertical axis indicates the amplitude deviation (unit: dB).
  • a distortion removal value (unit: dB) is added to each curve in the graph.
  • FIG. 19 it can be seen that when the amplitude deviation and the phase deviation are small, the distortion removal amount is large, but the distortion removal amount is small as the amplitude deviation and phase deviation are large.
  • the FF amplifier 25A of the present embodiment has a phase shift circuit 36 having a matching circuit in the subsequent stage of the variable phase shifter 61 as shown in FIG.
  • control circuit 26A controls the control voltages Vpm and Vpe
  • the control circuit 26A controls the control voltages Vpm and Vpe, so that the frequency such as the group delay time characteristics (characteristics related to the frequency of the group delay time) is provided. Characteristics can be adjusted.
  • the FF amplifier 25A when non-linear distortion is removed, if there is an amplitude deviation or phase deviation in the non-linear distortion band of the modulated wave, the removal amount of the non-linear distortion deteriorates. In particular, regarding the phase, if there is a deviation in the group delay time, the phase deviation increases.
  • FIG. 20A and 20B are diagrams schematically illustrating an example of the group delay time characteristic of the FF amplifier 25A.
  • FIG. 20A shows the group delay time characteristic before adjustment
  • FIG. 20B shows the group delay time characteristic after adjustment.
  • the group delay time characteristic is almost flat over the entire use band Wa, whereas in the high frequency region Wp, a group delay time deviation is generated as compared with the low frequency region. . Due to the group delay time deviation, a phase deviation occurs in the band of the nonlinear distortion of the modulated wave, and the distortion removal amount is deteriorated. Therefore, by adjusting the control voltages Vpm and Vpe, it is possible to make the characteristics of the high frequency region Wp flat as shown in FIG. 20B. In FIG.
  • the group delay time characteristic of the entire use band Wa is worse than the group delay time characteristic of FIG. 20A, but the group delay time characteristic of the high frequency region Wa is improved.
  • the control circuit 26A switches the operation state of the FF amplifier 25A from the state 2 to the state 3 when a transmission RF signal in a specific band is detected, thereby reducing the distortion removal amount. Can be suppressed.
  • FIG. 21 is a graph showing an example of an effect obtained by suppressing deterioration of the distortion removal amount.
  • the graph of FIG. 21 represents an example of the power spectrum of the output of the FF amplifier 25A.
  • the horizontal axis represents frequency and the vertical axis represents power.
  • the distortion removal amount deteriorates, a portion ka affected by the distortion appears in the power spectrum in the low frequency region of FIG. 21, and the power spectrum may be unbalanced with respect to the frequency. Therefore, when the control voltage Vpm for the phase shift circuit 36 is adjusted, the amplitude deviation and the phase deviation of the main amplifier 34 are reduced, and the portion ka affected by the distortion is changed to the portion kb. Thereby, the imbalance of the power spectrum can be improved.
  • FIG. 22 is a diagram showing a schematic configuration of the transmission system according to the third embodiment of the present invention.
  • the transmission system according to the present embodiment includes a modulator 10 that supplies an n-channel transmission RF signal, and a feedforward transmitter (FF) that has a common amplification configuration that can amplify the n-channel transmission RF signals collectively.
  • Transmitter 20B Transmitter
  • the FF transmitter 20B includes input ports 21 1 to 21 n , a power combiner 22, an FF amplifier 25, an output port 29, and a control circuit 26B.
  • the FF transmitter 20B further includes a power detector 23 that detects the power of the combined signal output from the power combiner 22 and supplies a detection signal Da indicating the detection result to the control circuit 26B.
  • the control circuit 26B Based on the detection signal Da, the control circuit 26B generates a control signal CS that individually determines the operating states of the circuit elements 32, 33, 34, 41, 52, 53, and 54 that constitute the FF amplifier 25, and this control signal By supplying CS to the FF amplifier 25, the operating state of the FF amplifier 25 can be controlled.
  • the control circuit 26B Based on the detection signal Da, the control circuit 26B measures the operation number of the modems M 1 to M n , that is, the total power of the transmission RF signals input to the input ports 21 1 to 21 n , and uses the reference table (TBL) 27B.
  • TBL reference table
  • the control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, and Vge can be determined according to the total power.
  • TBL 27B a correspondence relationship between the total power value of the input RF signal and a selectable state of the FF amplifier 25 is stored.
  • the control circuit 26B can select the state of the FF amplifier 25 suitable for the total power using the TBL 27B.
  • the FF transmitter 20B in the third embodiment has a common amplification configuration similar to that in the first embodiment, and the level of the combined signal changes according to the n-channel transmission signal. Can do. Even when the level of the combined signal changes, the control circuit 26B determines the control parameters Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge based on the detection signal Da, and these control parameters Ca, Cb, Since the control signal CS is generated using Cc, Cd, Vdm, Vgm, Vde, and Vge, the FF amplifier 25 changes to an appropriate operation state designated by the control signal CS according to the change in the level of the synthesized signal. Transition is possible. Therefore, a common amplification configuration that can amplify the transmission signals of a plurality of channels with high efficiency is realized.
  • first to third embodiments can be freely combined, any constituent element of each embodiment can be modified, or any constituent element of each embodiment can be omitted.
  • the feedforward transmitter and the transmission system according to the present invention can amplify the transmission signals of a plurality of channels at a time with high efficiency, and are therefore suitable for use in wireless communication technologies such as mobile communication and satellite communication. ing.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Amplifiers (AREA)
  • Transmitters (AREA)

Abstract

La présente invention concerne un émetteur à correction aval (20) qui comprend : des ports d'entrée (de 211 à 21n) dans lesquels des signaux d'émission d'une pluralité de canaux doivent être entrés ; un synthétiseur de signal (22) permettant de synthétiser les signaux d'émission ; un amplificateur à correction aval (25) permettant d'amplifier la puissance d'un signal de sortie provenant du synthétiseur de signal (22) ; un circuit de commande (26) permettant de générer un signal de commande (CS) afin de déterminer l'état de fonctionnement de l'amplificateur à correction aval (25) et de fournir le signal de commande (CS) à l'amplificateur à correction aval (25) ; et des unités de détection de signal (de 231 à 23n) permettant d'émettre des signaux de détection (DS) indiquant des résultats de détection des signaux d'émission. Le circuit de commande (26) détermine des paramètres de commande (Ca, Cb, Cc, Cd, Vdm, Vgm, Vde, Vge) sur la base des signaux de détection (DS), et génère le signal de commande (CS) à l'aide des paramètres de commande.
PCT/JP2016/087564 2016-12-16 2016-12-16 Émetteur à correction aval et système d'émission WO2018109927A1 (fr)

Priority Applications (2)

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JP2017534364A JP6242548B1 (ja) 2016-12-16 2016-12-16 フィードフォワード送信機及び送信システム
PCT/JP2016/087564 WO2018109927A1 (fr) 2016-12-16 2016-12-16 Émetteur à correction aval et système d'émission

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002290165A (ja) * 2001-03-27 2002-10-04 Hitachi Kokusai Electric Inc フィードフォワード増幅器の制御方法及びそれを用いたフィードフォワード増幅器
JP2007013946A (ja) * 2005-06-03 2007-01-18 Ntt Docomo Inc 帯域選択型フィードフォワード増幅器

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002290165A (ja) * 2001-03-27 2002-10-04 Hitachi Kokusai Electric Inc フィードフォワード増幅器の制御方法及びそれを用いたフィードフォワード増幅器
JP2007013946A (ja) * 2005-06-03 2007-01-18 Ntt Docomo Inc 帯域選択型フィードフォワード増幅器

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