KR101699755B1 - Signal processing apparatus for amplitude modulation - Google Patents

Signal processing apparatus for amplitude modulation Download PDF

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Publication number
KR101699755B1
KR101699755B1 KR1020150190375A KR20150190375A KR101699755B1 KR 101699755 B1 KR101699755 B1 KR 101699755B1 KR 1020150190375 A KR1020150190375 A KR 1020150190375A KR 20150190375 A KR20150190375 A KR 20150190375A KR 101699755 B1 KR101699755 B1 KR 101699755B1
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South Korea
Prior art keywords
signal
phase
amplitude modulation
processing apparatus
signals
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KR1020150190375A
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Korean (ko)
Inventor
최웅세
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한국산업기술대학교산학협력단
주식회사 싸이트론
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Priority to KR1020150190375A priority Critical patent/KR101699755B1/en
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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
    • H03F1/3241—Modifications of amplifiers to reduce non-linear distortion using predistortion circuits
    • H03F1/3282—Acting on the phase and the amplitude of the input signal
    • 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
    • H03F1/3223—Modifications of amplifiers to reduce non-linear distortion using feed-forward
    • 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
    • H03F1/3241—Modifications of amplifiers to reduce non-linear distortion using predistortion circuits
    • H03F1/3282—Acting on the phase and the amplitude of the input signal
    • H03F1/3288—Acting on the phase and the amplitude of the input signal to compensate phase shift as a function of the amplitude
    • 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

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Amplifiers (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)

Abstract

The present invention relates to a signal processing apparatus for amplitude modulation. According to the present invention, the signal processing apparatus includes: a distribution unit which distributes input signals into first and second signals; a variable attenuation unit which generates variably attenuated first signals based on control signals and the distributed first signals; a phase varying unit which generates first signals with varied phases based on a control voltage and the variable attenuated first signals; a directional coupling unit which gives feedback to the first signals generated by amplifying the first signals with varied phases through a power amplifier; and a quadrature detection unit which detects quadrature (Q) signals and in-phase (I) signals based on the first signals provided with the feedback and the distributed second signals. According to the present invention, the signal processing apparatus can provide better efficiency.

Description

[0001] SIGNAL PROCESSING APPARATUS FOR AMPLITUDE MODULATION [0002]

The present invention relates to a signal processing apparatus for amplitude modulation.

Amplitude modulation is a method of changing the amplitude according to the amplitude of a signal to be transmitted to a carrier wave that is a base of radio waves.

At this time, the signal wave has irregular amplitude and frequency according to time, while the carrier wave has a constant amplitude and has a constant angular frequency.

However, there is a problem in that transmission quality is degraded due to distortion occurring in amplitude modulation, so a technique capable of minimizing distortion is needed.

The present invention proposes a technique capable of improving transmission quality by minimizing distortion.

The present invention aims at solving all of the above problems.

It is another object of the present invention to provide compensation for amplitude modulation and nonlinear distortion of an RF power amplifier.

Another object of the present invention is to optimize a feedback circuit which is a circuit for amplitude-modulating an RF input signal using a sinusoidal signal as a reference of a modulation frequency and eliminating harmonic components generated during amplitude modulation .

In order to accomplish the objects of the present invention as described above and achieve the characteristic effects of the present invention described below, the characteristic structure of the present invention is as follows.

According to an embodiment, there is provided a signal processing apparatus for amplitude modulation, comprising: a distributor for distributing an input signal to a first signal and a second signal; A variable attenuator for generating a variable attenuated first signal based on the distributed first signal and the control signal; A phase varying unit that generates a first signal that is phase-shifted based on the first variable-attenuated signal and a control voltage; A directional coupler for feeding back the first signal amplified through the power amplifier by the phase-shifted first signal; And a quadrature detector for detecting an I (In-phase) signal and a Q (Quadrature) signal based on the distributed second signal and the feedbacked first signal.

The control signal may be generated based on the sine wave signal and the detected Q signal.

The variable attenuator may modulate the amplitude by mixing the distributed first signal and the control signal.

The phase varying unit may compensate for phase distortion when the detected I signal is deformed and the control voltage is varied.

The directional coupler may output the amplified first signal as an output signal.

The present invention can constitute a feedback circuit as a circuit that compensates for nonlinear distortion due to harmonic components by means of optimizing amplitude modulation of an RF power amplifier. Therefore, the present invention has the effect of obtaining better efficiency.

The present invention has an effect that the frequency of the sinusoidal signal can be changed to be changed to a desired modulation frequency.

1 is a block diagram illustrating a signal processing apparatus for amplitude modulation according to an embodiment of the present invention.
2 shows a sine wave signal and a sine wave anti-phase signal according to an embodiment of the present invention.
3 shows an amplitude modulated signal according to an embodiment of the present invention.
4 shows a circuit for compensating for amplitude distortion according to an embodiment of the present invention.
5 shows a circuit for compensating for phase distortion according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a signal processing apparatus for amplitude modulation according to an embodiment of the present invention. Referring to FIG. 1, the overall system of a signal processing apparatus for amplitude modulation can be known.

According to one embodiment, the entire system of the signal processing apparatus for amplitude modulation may be configured to include a distributor, a variable attenuator, a phase shifter, a directional coupler, and a quadrature detector. In some cases, the signal processing apparatus for amplitude modulation may include a distribution unit, a variable attenuation unit, a phase variable unit, a directional coupling unit, a quadrature detection unit, an addition filter unit, an amplification filter unit, have. Further, in some cases, the signal processing apparatus for amplitude modulation may be configured to include a power amplifier. In some cases, the signal processing apparatus for amplitude modulation may be a power amplifier. Also, as occasion demands, the signal processing apparatus for amplitude modulation may be connected to a power amplifier. At least one of an electronic circuit, an electric circuit, an integrated circuit, an electronic device, and a magnetic device may be used as the dispersion unit, the variable attenuation unit, the phase variable unit, the directional coupling unit, the quadrature detection unit, the addition filter unit, But the present invention is not limited thereto.

The distributing unit may distribute the input signal of the signal processing device for amplitude modulation to the first signal and the second signal. At this time, the input signal may be a continuous wave (CW) as a radio frequency (RF). Also, the distributed first signal and the distributed second signal may be the same signal.

The variable attenuator can generate the first signal distributed by the distributor and the first signal variable attenuated based on the control signal. At this time, the control signal can be generated based on the sine wave signal and the Q signal detected by the quadrature detection section. The sinusoidal signal may be a sinusoidal wave as a modulation frequency. The Q signal may be a quadrature signal. The Q signal may be at least one of a chrominance signal, a chrominance signal, a chromaticity signal, and a color signal as a quadrature signal. Further, the variable attenuator can modulate the amplitude by mixing the control signal with the first signal distributed by the distributor.

The phase varying section can generate the first signal that is variable attenuated by the variable attenuation section and the first signal that is phase-shifted based on the control voltage. The phase varying section can compensate for phase distortion when the I signal detected by the quadrature detection section is deformed and the control voltage is varied. The I signal may be an In-phase signal. The I signal may be at least one of a chrominance signal, a color difference signal, a chromaticity signal, and a color signal as the in-phase signal.

The directional coupler may feed back the first signal whose phase is varied by the phase shifter through the power amplifier. The directional coupler may output the first signal amplified by the phase shifter through the power amplifier to the output signal of the signal processor for amplitude modulation. Of course, the output signal may be an AM (Amplitude Modulation) signal as a radio frequency.

The quadrature detector can detect an I (In-phase) signal and a Q (Quadrature) signal based on the divided second signal and the first signal fed back by the directional coupler. At this time, the I signal and the Q signal may be at least one of a chrominance signal, a color difference signal, a chromaticity signal, and a color signal.

According to one embodiment, the signal processing apparatus for amplitude modulation may be constituted by a circuit that modulates the amplitude using feedback and compensates for distortion. Further, the signal processing device for amplitude modulation may be configured to include a circuit for modulating the amplitude of an RF (Radio Frequency) power amplifier and compensating for nonlinear distortion. For example, a signal processing apparatus for modulation can amplitude-modulate an RF input signal by using a sinusoidal signal as a reference of a modulation frequency. Further, the signal processing apparatus for modulation may include a feedback circuit which is a circuit for eliminating harmonic components generated in amplitude modulation. Further, the signal processing apparatus for modulation may be configured to include a nonlinear distortion compensation circuit that operates to optimize the feedback circuit to minimize the distortion.

Harmonic components generated during amplitude modulation may act as a noise source, which may degrade the transmission quality, and countermeasures against distortion of the high output amplifier are needed. Therefore, the signal processing apparatus for modulation can be designed in consideration of obtaining a good efficiency including an amplitude modulation and distortion compensation circuit.

For example, a signal processing device for amplitude modulation may include a power amplifier that modulates the amplitude using a feedback signal. Specifically, the distributing unit of the signal processing apparatus for amplitude modulation can distribute the input CW signal 101 to the first signal 102 of the power amplification path and the second signal 103 of the reference signal path. At this time, the first signal 102 and the second signal 103 may be the same.

Next, the directional coupler of the signal processing apparatus for amplitude modulation can feedback the amplified signal through the power amplification path. For example, the quadrature detection unit of the signal processing apparatus for amplitude modulation detects the I and Q signals by quadrature detection of the first signal 104 fed back by the directional coupler and the second signal 103 of the reference signal path can do.

Next, the amplification filter unit of the signal processing apparatus for amplitude modulation can receive the detected I signal and compensate for the phase distortion of the detected I signal to generate the phase-distortion-compensated I signal 106. [ The addition filter section of the signal processing apparatus for amplitude modulation amplifies and adds the detected Q signal to the anti-phase signal of the sinusoidal signal 108, which is a reference signal of the modulation frequency, Thereby generating a compensated Q signal 105. [

According to one embodiment, the signal processing apparatus for amplitude modulation may be constituted by a circuit including the following features. For example, a signal processing apparatus for amplitude modulation extracts a Q signal by quadrature-detecting a first signal 104 fed back by a directional coupler and a second signal 103 as a reference signal, Phase signal of the signal 108. < RTI ID = 0.0 > At this time, the signal processing apparatus for amplitude modulation can generate the envelope signal 105 of the amplitude modulation signal by adding the Q signal extracted by the quadrature detection with the sinusoidal wave signal 108. Next, the signal processing apparatus for amplitude modulation receives the envelope signal 105 as the control signal of the variable attenuator and mixes it with the first signal 102 distributed by the distributor as the CW signal 101, The first signal 107 can be generated. That is, the variable attenuator of the signal processing apparatus for amplitude modulation can generate the first signal 107 amplitude-modulated based on the divided first signal 102 and the envelope signal 105 generated by the adder filter unit have.

According to one embodiment, the delay element section of the signal processing apparatus for amplitude modulation can correct the time difference in the circuit path of the signal processing apparatus for amplitude modulation. For example, the delay element section includes a first circuit path generated in the order of a distribution section, a variable attenuation section, a phase variable section, a power amplifier, a directional coupling section, and a quadrature detection section, The speed and time difference of the processed signal between circuit paths can be corrected.

That is, the delay element unit adjusts the processing time of the first signal 104 fed back by the directional coupler and the distributed second signal 103, and corrects the time difference so that it is processed by the quadrature detector at the same time . For example, the delay element section can adjust the time at which the first signal 104 fed back by the directional coupler reaches the quadrature detector section. On the other hand, the delay element unit may delay the first signal 104 fed back by the directional coupler. For example, the delay element unit receives the first signal 104 output from the directional coupler and fed back by the directional coupler, and receives the first signal 104 fed back by the directional coupler according to the set time or set time interval 104 can be output through a circuit as a quadrature detection unit.

Also, as the case may be, the delay element section stores the first signal 104 fed back by the directional coupler, and when the quadrature detector receives the distributed second signal 103, the stored feedback first signal 104) or may be controlled and triggered by certain circuit components. At this time, the specific circuit component may be a quadrature detection part. Of course, the quadrature detector may detect the I signal and the Q signal on the basis of the input divided second signal 103 and the feedback first signal 104. [ That is, the quadrature detector sets the divided second signal 103 input at the same time or time and the divided second signal 103 out of the feedbacked first signal 104 as the reference frequency, The I signal or the Q signal can be detected by utilizing the amount of change of the first signal 104 fed back due to the influence of the signal 103. [

2 shows a sine wave signal and a sine wave anti-phase signal according to an embodiment of the present invention.

Referring to FIG. 2, it can be seen that a signal processing apparatus for amplitude modulation generates an amplitude modulation envelope based on a sinusoidal wave signal and a sine wave anti-phase signal. For example, a signal processing apparatus for amplitude modulation generates an amplitude modulation envelope by adding a sinusoidal wave signal 210 and an inverse phase signal 220, and mixes an envelope formed with a first signal, which is an input CW signal, A modulated first signal can be generated.

That is, the addition filter section of the signal processing apparatus for amplitude modulation can form the amplitude modulation envelope by adding the sine wave signal 210 and the anti-phase signal 220. The variable attenuation unit of the signal processing apparatus for amplitude modulation can generate the amplitude-modulated first signal by mixing the envelope formed with the first signal, which is the input CW signal.

3 shows an amplitude modulated signal according to an embodiment of the present invention.

Referring to FIG. 3, it can be seen that the signal processing apparatus for amplitude modulation generates an amplitude-modulated signal. For example, a signal processing apparatus for amplitude modulation can generate an amplitude-modulated signal by mixing a sinusoidal signal and a reverse-phase signal

That is, the variable attenuation unit of the signal processing apparatus for amplitude modulation mixes the amplitude modulation envelope generated by adding the sine wave signal 210 and the anti-phase signal 220 by the addition filter unit and the divided first signal, Lt; / RTI >

According to one embodiment, a signal processing apparatus for amplitude modulation can compensate for a distortion signal generated upon high output amplification using a quadrature detected signal. At this time, the quadrature-detected signal may be at least one of an I signal and a Q signal. The I signal and the Q signal may be at least one of a chrominance signal, a color difference signal, a chromaticity signal, and a color signal. Further, the I signal may be a signal having a phase angle of 57 degrees with respect to a color burst. At this time, the I signal can be generated by mixing the output signals ER, EG, and EB of three colors of RGB (Red, Green, Blue) into a matrix circuit at a ratio of EI = 0.60ER-0.28EG-0.32EB. Also, the Q signal may be a signal that is quadrature to the I signal. The Q signal may be a signal having a phase angle of 147 with respect to the color burst. At this time, the Q signal can be generated by mixing the output signals ER, EG, and EB of the three colors of RGB (Red, Green, Blue) with a matrix circuit at a ratio of EQ = 0.21ER-0.52EG + 0.31EB.

4 shows a circuit for compensating for amplitude distortion according to an embodiment of the present invention.

Referring to FIG. 4, a circuit for compensating amplitude distortion of a signal processing apparatus for amplitude modulation can be known.

For example, the signal processing apparatus for amplitude modulation can generate a Q signal 401 extracted by quadrature detection of a feedback (Feed Back) signal as a reverse phase (180 degrees) signal of the sinusoidal signal 402. At this time, the signal processing apparatus for amplitude modulation has the effect of improving the distortion performance due to nonlinear distortion as well as the amplitude modulation function. Q signal 401 is amplified by an amplifier AMPL and added by a sine wave signal 402 which is a sin wave and an adder ADDR and amplified by an amplifier to generate an envelope signal 403 have.

That is, the adder filter section of the signal processing apparatus for amplitude modulation can generate an envelope signal as a control signal capable of controlling the variable attenuation section as an adder / active filter using an amplifier and an adder. Of course, the variable attenuation unit of the signal processing apparatus for amplitude modulation receives the envelope signal as a control signal, generates a first signal, which is a distributed CW signal, as a first signal 405 that is amplitude-modulated according to a control signal, And outputs the first signal 405.

5 shows a circuit for compensating for phase distortion according to an embodiment of the present invention.

Referring to FIG. 5, a circuit for compensating for phase distortion of a signal processing apparatus for amplitude modulation can be known.

Since the power amplification causes phase distortion by the nonlinear device, it is necessary to compensate the generated phase distortion. For example, when the phase distortion occurs, the I signal 501 extracted by the quadrature detection of the first feedback signal may be deformed. At this time, the signal processing apparatus for amplitude modulation can compensate for phase distortion by changing the phase variable valve control voltage by using an amplifier and a filter so that the phase of the first signal 502 of the power amplification path is not changed. The I signal 501 is amplified by an amplifier (AMPL), filtered by a low pass filter (LPF), and amplified by an amplifier to produce a modified I signal.

That is, the amplification filter unit of the signal processing apparatus for amplitude modulation generates an I / O signal modified as an amplifier / active filter by using an amplifier and a low-pass filter as a signal or a control voltage capable of varying the control voltage to control the phase attenuation unit can do. Of course, the phase shifting unit of the signal processing apparatus for amplitude modulation receives the amplitude-modulated first signal 502 and compensates for the phase distortion of the amplitude-modulated first signal 502 to generate a first signal 503 and output the first signal 503 whose phase is unchanged.

According to one embodiment, the signal processing apparatus for amplitude modulation can change the frequency of a sinusoidal signal and output an input signal with a desired modulation frequency. The signal processing device for amplitude modulation may include a circuit for varying the amplitude modulation frequency. For example, the signal processing device for amplitude modulation can vary the frequency of the sinusoidal signal and can vary the amplitude modulation frequency of the power amplifier according to the variable frequency. Further, the signal processing apparatus for amplitude modulation can process amplitude distortion and phase distortion compensation even when the frequency of the sinusoidal signal is changed.

According to one embodiment, the signal processing apparatus for amplitude modulation can constitute a feedback circuit as a circuit that compensates for nonlinear distortion due to harmonic components by means of optimizing the amplitude modulation of the RF power amplifier, There is an effect that it is possible to provide an amplitude modulation and distortion compensation circuit. Further, the signal processing apparatus for amplitude modulation has the effect of changing the frequency of the sinusoidal signal to vary the desired modulation frequency.

The methods according to embodiments of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible.

Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the equivalents of the claims, as well as the claims that follow.

Claims (5)

A signal processing apparatus for amplitude modulation, comprising:
A distributor for distributing the input signal to the first signal and the second signal;
A variable attenuator for generating a variable attenuated first signal based on the distributed first signal and the control signal;
A phase varying unit that generates a first signal that is phase-shifted based on the first variable-attenuated signal and a control voltage;
A directional coupler for feeding back the first signal amplified through the power amplifier by the phase-shifted first signal; And
A quadrature detection unit for detecting an I (In-phase) signal and a Q (Quadrature) signal based on the distributed second signal and the feedback first signal,
Lt; / RTI >
Wherein the control signal comprises:
A sinusoidal wave signal and the detected Q signal,
Wherein the quadrature detector extracts the Q signal by quadrature-detecting the first signal fed back by the directional coupler and the divided second signal,
The extracted Q signal is generated as a reverse phase signal of the sinusoidal signal,
An envelope signal of an amplitude modulation signal is generated based on the Q signal generated by the anti-phase signal of the sinusoidal signal and the sinusoidal signal, the envelope signal is input as the control signal,
Wherein the variable attenuator mixes the distributed first signal and the control signal to generate a first amplitude modulated signal,
Wherein the phase varying unit compensates for the phase distortion of the amplitude-modulated first signal when the detected I signal is deformed to vary the control voltage. delete delete delete The method according to claim 1,
The directional coupler includes:
And outputs the amplified first signal as an output signal.

KR1020150190375A 2015-12-30 2015-12-30 Signal processing apparatus for amplitude modulation KR101699755B1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010028084A (en) * 1999-09-17 2001-04-06 서평원 Predistorter of power amplifier
JP2003142950A (en) * 2001-10-31 2003-05-16 Hitachi Kokusai Electric Inc Power amplifier
JP2004248109A (en) * 2003-02-14 2004-09-02 Matsushita Electric Ind Co Ltd Distortion elimination controller and feedforward amplifier
KR101150734B1 (en) * 2008-09-10 2012-06-11 가부시키가이샤 엔.티.티.도코모 Power series predistorter and control method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010028084A (en) * 1999-09-17 2001-04-06 서평원 Predistorter of power amplifier
JP2003142950A (en) * 2001-10-31 2003-05-16 Hitachi Kokusai Electric Inc Power amplifier
JP2004248109A (en) * 2003-02-14 2004-09-02 Matsushita Electric Ind Co Ltd Distortion elimination controller and feedforward amplifier
KR101150734B1 (en) * 2008-09-10 2012-06-11 가부시키가이샤 엔.티.티.도코모 Power series predistorter and control method thereof

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