JP2008113077A - Distortion compensating device, amplifier, and distortion compensating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely suppress distortion even with a wide band and a wide dynamic range, to perform distortion compensation with low power consumption, and to facilitate adjustment. <P>SOLUTION: A first distributor 102 distributes an input signal to two systems. A second distributor 104 distributes the input signal distributed to the two systems further to two systems. A distortion generating circuit 125 generates a distortion component to generate an input signal including the distortion component. A first synthesizer 111 puts the input signal and the signal including the distortion component together to extract the distortion component. A frequency adjusting circuit 114 adjusts the variation quantity of an amplitude or the variation quantity of a phase due to frequency characteristics to unbalance levels of the distortion component by frequencies. A second synthesizer 115 puts the input signal and distortion component together. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a distortion compensation device, an amplification device, and a distortion compensation method, and more particularly to a distortion compensation device, an amplification device, and a distortion compensation method that suppress intermodulation distortion caused by nonlinearity of input / output characteristics of a high-frequency amplifier circuit.

  Conventionally, mobile communication base station apparatuses are required to have an amplifier having efficient amplification and high distortion suppression performance. However, efficient amplification and high distortion suppression performance are generally in a trade-off relationship. Therefore, in order to realize efficient amplification and high distortion suppression performance, for example, a high distortion suppression performance is realized while operating efficiently by a predistortion method.

  FIG. 5 is a diagram showing a configuration of a conventional distortion compensation apparatus 1. As shown in FIG. 5, a conventional distortion compensation apparatus 1 includes an input terminal 10 to which an input signal is input, an amplifier 12 that amplifies the input signal and outputs an amplified signal, and an output terminal 13 that outputs an output signal. And a distortion compensation circuit 11 used for suppressing distortion components generated in the amplifier 12.

  FIGS. 6A to 6C are diagrams representing the carrier signal and the distortion signal of FIG. 5 in a vector form. 6A is a diagram illustrating an output waveform of the distortion compensation circuit 11, FIG. 6B is a diagram illustrating an output waveform of the amplifier 12 when distortion compensation is not performed, and FIG. It is a figure which shows the output waveform of the amplifier 12 at the time of distortion compensation.

  As shown in FIG. 6B, the amplifier 12 generates intermodulation distortion (hereinafter referred to as “distortion”) signals h <b> 1 and h <b> 2 generated by the nonlinear amplification characteristics of the input and output of the amplifier 12. As shown in FIG. 6A, the distortion compensation circuit 11 converts distortion signal components h ′ 1 and h ′ 2 having the same amplitude and anti-phase characteristics with respect to the distortion signals h 1 and h 2 of the amplifier 12. Generated in the part. By inputting the signal shown in FIG. 6A to the amplifier 12, the distortion compensation circuit 11 can suppress distortion by vector synthesis of the distortion as shown in FIG. 6C.

  Conventionally, the level difference between the low frequency IM3L and the high frequency IM3U of the distortion generated in the distortion generation circuit, and the level between the low frequency IM3L and the high frequency IM3U of the distortion generated in the power amplifier. A configuration has been proposed in which the difference is made equal to each other and distortion is suppressed over a wide band (for example, Patent Document 1).

  The operation principle of the distortion compensation circuit of Patent Document 1 will be described with reference to FIG. FIG. 7 is a block diagram showing a configuration of a conventional distortion compensation circuit 11.

  In FIG. 7, the distortion compensation circuit 11 includes an input terminal 20 to which an input signal is input, a first distributor 21 that distributes the input signal, and propagation of one output signal distributed by the first distributor 21. A first delay circuit 22 for delaying time, a second distributor 23 for further distributing the other output signal distributed by the first distributor 21, and one of the signals distributed by the second distributor 23. An input circuit that adjusts input matching of a distortion generating element 26 that inputs a second delay circuit 24 that delays the propagation time of the output signal and the other signal distributed by the second distributor 23 and generates a distortion signal. 25, a distortion generating element 26 that generates a distortion component, a distortion generating circuit 50 that includes an output circuit 27 that adjusts the output matching of the distortion generating element 26, and a distortion component generated by the distortion generating element 26. Signal amplitude generation A first variable attenuator 28 that adjusts the phase, a first variable phase shifter 29 that adjusts the phase component of the signal including the distortion component of the distortion generating element 26, and an output signal from the first variable phase shifter 29 A first synthesizer 30 for synthesizing the output signal from the second delay circuit 24; a second variable attenuator 31 for adjusting the amplitude component of the signal from the first synthesizer 30; and a second variable attenuation. A second variable phase shifter 32 for adjusting the phase component of the signal from the shifter 31; a second combiner 33 for combining the signal from the first delay circuit 22 and the signal from the second variable phase shifter 32; And an output terminal 34 for outputting a signal synthesized by the second synthesizer 33.

  With this configuration, the input signal input from the input terminal 20 is distributed by the first distributor 21. One input signal distributed to the two systems by the first distributor 21 is further distributed by the second distributor 23. One input signal distributed by the first distributor 21 generates a distortion signal different from the input signal input to the input terminal 20 due to the nonlinearity of the distortion generating element 26. One input signal in which the distortion signal is generated is subjected to vector adjustment of amplitude and phase by the first variable attenuator 28 and the first variable phase shifter 29, and is input to the first combiner 30. The other transmission signal distributed to the two systems by the second distributor 23 is input to the first combiner 30 through the second delay circuit 24. The distortion compensation circuit 50 suppresses the transmission signal component by adjusting the path 2 and the path 3 so as to have the same attenuation characteristic and have an antiphase relationship. Thereby, the 1st combiner | synthesizer 30 can extract only a distortion component. The signal synthesized by the first synthesizer 30 is subjected to phase and amplitude vector adjustment through the second variable attenuator 31 and the second variable phase shifter 32 and is input to the second synthesizer 33. . The second combiner 33 extracts the distortion component by combining the transmission signal component of the path 1 and the path 4 and the path-adjusted signal of the path 4 by combining the path 2 and the path 3 so that the distortion component is unique. It is possible to configure the distortion compensation circuit 11 that can be controlled to a high level.

  FIGS. 8A to 8C are diagrams representing the carrier signal and the distortion signal in FIG. 5 in a vector form. FIG. 8A is a diagram showing an output waveform of the distortion compensation circuit 11, FIG. 8B is a diagram showing an output waveform of the amplifier 12 when distortion compensation is not performed, and FIG. It is a figure which shows the output waveform of the amplifier 12 at the time of distortion compensation. FIG. 9 is a diagram showing the amplitude phase characteristics of the signal of the distortion compensation circuit 11.

  As shown in FIGS. 8A to 8C, when a wideband signal having a large frequency interval between input signals (two signals f1 and f2 in FIGS. 8A to 8C) is obtained. In the distortion component generated when amplified by the amplifier 12, as shown in FIG. 8B, an imbalance occurs between the level of the distortion component h1 and the level of the distortion component h2. However, an unbalance does not occur in the distortion component generated by the distortion generating element 26 that operates with a low power and uses a high impedance device, as shown in FIG. Therefore, when the signal of FIG. 8A is input to the amplifier 12, as shown in FIG. 8C, distortion compensation is performed by the vector difference between the distortion component generated by the distortion compensation circuit 11 and the distortion component generated by the amplifier 12. Therefore, the remaining distortion component h3 is output from the distortion compensation circuit 11. Therefore, the output circuit 27 of the distortion generating element 26 is adjusted so that the path 3 has a frequency characteristic that attenuates the signal component on the high frequency side, as shown in FIG.

  FIG. 10A to FIG. 10C are diagrams representing the carrier signal and the distortion signal of FIG. 5 in a vector form. 10A is a diagram illustrating an output waveform of the distortion compensation circuit 11, FIG. 10B is a diagram illustrating an output waveform of the amplifier 12 when distortion compensation is not performed, and FIG. It is a figure which shows the output waveform of the amplifier 12 at the time of distortion compensation.

By giving the path 3 a frequency characteristic that attenuates the signal component on the high frequency side, as shown in FIG. 10 (a), signals with unbalanced levels such as the distortion signal components h'1 and h'2 can be obtained. The generated signal is input to the amplifier 12 that generates an unbalanced level distortion component as shown in FIG. 10C, whereby a signal with suppressed distortion is obtained.
JP 2003-332852 A

  However, in the conventional apparatus, the unbalance of the distortion signal component is adjusted by the path 3 in FIG. 7, but between the path 2 and the path 3 in FIG. Differences and phase differences occur. FIG. 11 is a diagram illustrating an amplitude difference and a phase difference generated between the path 2 and the path 3 due to the frequency characteristics.

  12 (a) shows the signal waveform of the signal at point a in FIG. 7, and FIG. 12 (b) shows the output waveform of the signal at point b in FIG. ) Shows the output waveform of the signal at point c in FIG. 7, and FIG. 12 (d) shows the output waveform of the signal at point d in FIG. That is, as shown in FIG. 13C, the transmission signal is imbalanced due to the amplitude difference or phase difference with respect to the frequency, and thus the transmission signal is not transmitted correctly.

  Therefore, for example, if the amplitude of the signal in the path 2 and the signal in the path 3 are different and the phases are in an opposite phase relationship, when the signal in the path 2 and the signal in the path 3 are combined, h5 occurs. The same applies to the case where the signal in the path 2 and the signal in the path 3 have the same amplitude and the phase is not in an antiphase relationship.

  FIG. 13A to FIG. 13C are vector representations of the carrier signal and the distortion signal of FIG. FIG. 13A is a diagram illustrating an output waveform of the distortion compensation circuit 11, FIG. 13B is a diagram illustrating an output waveform of the amplifier 12 when distortion compensation is not performed, and FIG. It is a figure which shows the output waveform of the amplifier 12 at the time of distortion compensation.

  That is, as shown in FIG. 13C, the amplitude or phase between the input signal f1 and the input signal f2 is unbalanced due to the amplitude difference or phase difference due to the frequency characteristics, and therefore the input signal is amplified and transmitted. There is a problem that it is not sent correctly.

  The present invention has been made in view of such a point, and can suppress distortion with high accuracy even in a wide band and a wide dynamic range, and can also perform distortion compensation with low power consumption and can be easily adjusted. An object of the present invention is to provide a distortion compensation device, an amplification device, and a distortion compensation method.

  The distortion compensator according to the present invention includes a first distribution unit that distributes an input signal having a plurality of frequencies to two systems of a first signal and a second signal, and the second signal is further divided into two signals of a third signal and a fourth signal. Second distribution means for distributing to the system; distortion generating means for generating a distortion component in the fourth signal; the fourth signal including the distortion component and having the same amplitude and opposite phase as the third signal; A first synthesizing unit that extracts the distortion component by synthesizing with a third signal; and the first synthesizing unit that extracts the distortion component extracted by the first synthesizing unit and adjusts the amplitude or phase of the distortion component. A frequency adjustment unit that unbalances the level for each frequency of the distortion component; and a second synthesis unit that combines the first signal and the distortion component whose level is unbalanced by the frequency adjustment unit. Sampling .

  The distortion compensator of the present invention includes a first distribution unit that distributes an input signal having a plurality of frequencies to two systems of a first signal and a second signal, and the second signal is further divided into a third signal and a fourth signal. Adjusting the amplitude or phase of the second distribution means for distributing to the two systems, the distortion generating means for generating a distortion component in the fourth signal, and the fourth signal including the third signal and the distortion signal. The frequency adjustment means that unbalances the level of the distortion component for each frequency and makes the third signal and the fourth signal have the same amplitude and opposite phase, and the third frequency adjusted by the frequency adjustment means. First combining means for extracting the distortion component by combining the signal and the fourth signal including the distortion component; and a first combining means for combining the first signal and the distortion component extracted by the first combining means. Two synthesis means; Level detecting means for detecting the level of the input signal component remaining in the distortion component extracted by the first combining means, and adjusting the amplitude or phase in the frequency adjusting means so that the detected level is minimized. And a control means for controlling the adjustment amount at the time.

  The amplifying device according to the present invention includes a first distribution unit that distributes an input signal having a plurality of frequencies to two systems of a first signal and a second signal, and the second signal is further divided into two systems of a third signal and a fourth signal. Second distribution means for distributing to the fourth signal, distortion generating means for generating a distortion component in the fourth signal, the fourth signal including the distortion component and having the same amplitude and opposite phase as the fourth signal and the second signal. A first synthesizing unit that extracts the distortion component by synthesizing three signals; and the distortion extracted by the first synthesizing unit by adjusting an amplitude or phase in the distortion component extracted by the first synthesizing unit. A composite signal including a distortion component is generated by combining a frequency adjustment unit that unbalances the level of each component frequency, and the first signal and a distortion component whose level is unbalanced by the frequency adjustment unit. A second combining means that employs a configuration having a, and amplifying means for suppressing a strain component in the distortion component in the composite signal generated when the amplification amplifies the combined signal.

  The amplifying device of the present invention includes a first distribution unit that distributes an input signal having a plurality of frequencies into two systems of a first signal and a second signal, and the second signal is further divided into a third signal and a fourth signal. Adjusting the amplitude or phase of second distribution means for distributing to two systems, distortion generating means for generating a distortion component in the fourth signal, and the fourth signal including the third signal and the distortion signal Frequency adjusting means for making the level of each distortion component frequency unbalanced and making the third signal and the fourth signal have the same amplitude and opposite phase, and the third signal adjusted by the frequency adjusting means And combining the fourth signal including the distortion component with the first synthesis means for extracting the distortion component, and combining the first signal with the distortion component extracted with the first synthesis means. Distortion component Second combining means for generating a combined signal, level detecting means for detecting the level of the input signal component remaining in the distortion component extracted by the first combining means, and the detected level is minimized. And a control means for controlling an adjustment amount when adjusting the amplitude or phase in the frequency adjusting means, and amplifying the combined signal and suppressing a distortion component generated during the amplification with a distortion component included in the combined signal. And amplifying means.

  According to the distortion compensation method of the present invention, the step of distributing an input signal having a plurality of frequencies to two systems of a first signal and a second signal, and further distributing the second signal to two systems of a third signal and a fourth signal A step of generating a distortion component in the fourth signal, and combining the fourth signal and the third signal including the distortion component and having the same amplitude and opposite phase as the third signal. Extracting the distortion component by adjusting the amplitude or phase of the extracted distortion component to unbalance the level of the extracted distortion component for each frequency; and Generating a composite signal including a distortion component by synthesizing the unbalanced distortion component; and amplifying the composite signal and occurring during the amplification The distortion component so as to comprise the steps of: suppressing in distortion component contained in the composite signal.

  The distortion compensation method of the present invention includes a step of distributing an input signal having a plurality of frequencies into two systems of a first signal and a second signal, and the second signal is further divided into two systems of a third signal and a fourth signal. Distributing the first and second signals, generating a distortion component in the fourth signal, and adjusting the amplitude or phase of the third signal and the fourth signal including the distortion component for each frequency of the distortion component. The step of making the level unbalanced and making the third signal and the fourth signal have the same amplitude and opposite phase with each other, and the adjusted third signal and the fourth signal including the distortion component are synthesized. Extracting the distortion component, synthesizing the first signal and the extracted distortion component to generate a combined signal including the distortion component, and extracting the distortion component Detecting the level of the remaining input signal component, controlling the adjustment amount when adjusting the amplitude or the phase so that the detected level is minimized, and amplifying the combined signal And a step of suppressing a distortion component generated during the amplification with a distortion component included in the synthesized signal.

  According to the present invention, distortion can be suppressed with high accuracy even in a wide band and a wide dynamic range, distortion compensation can be performed with low power consumption, and adjustment can be easily performed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of distortion compensation apparatus 100 according to Embodiment 1 of the present invention. In FIG. 1, the input circuit 106, the distortion generation element 107, and the output circuit 108 constitute a distortion generation circuit 125. A path from the output terminal of the first distributor 102 to the input terminal of the second synthesizer 115 via the first delay circuit 103 is defined as a path 1. A path that reaches from the output terminal of the second distributor 104 to the input terminal of the first combiner 111 via the second delay circuit 105 is defined as a path 2. Further, a route from the output end of the second distributor 104 to the input end of the first combiner 111 via the distortion generation circuit 125, the first variable attenuator 109, and the first variable phase shifter 110 is routed. 3. Further, a route from the output end of the first synthesizer 111 to the input end of the second synthesizer 115 via the second variable attenuator 112, the second variable phase shifter 113, and the frequency adjustment circuit 114 is routed. 4.

  The input terminal 101 outputs the input signal to the first distributor 102 when an input signal is input.

  The first distributor 102 distributes the input signal input from the input terminal 101 into two systems of signals, and one of the two systems of distributed input signals (first signal) is the first delay circuit. The other input signal (second signal) is output to the second distributor 104.

  The first delay circuit 103 delays the propagation time of the input signal input from the first distributor 102 and outputs the delayed signal to the second combiner 115.

  The second distributor 104 further distributes the input signal input from the first distributor 102 into two signals. Then, the second distributor 104 outputs one input signal (third signal) to the second delay circuit 105 and outputs the other input signal (fourth signal) among the two distributed input signals. Output to the input circuit 106.

  The second delay circuit 105 delays the propagation time of the input signal input from the second distributor 104 and outputs the delayed signal to the first combiner 111.

  The input circuit 106 adjusts the input matching of the distortion generating element 107 with respect to the input signal input from the second distributor 104 and outputs the adjusted signal to the distortion generating element 107.

  The distortion generating element 107 generates a distortion component in the input signal input from the input circuit 106. Then, the distortion generation element 107 outputs an input signal including a distortion component to the output circuit 108.

  The output circuit 108 adjusts the output matching of the distortion generating element 107 and outputs an input signal including a distortion component input from the distortion generating element 107 to the first variable attenuator 109. Note that, unlike the above-described Patent Document 1, the output circuit 108 does not perform adjustment so that the distortion component output from the first combiner 111 is unbalanced.

  The first variable attenuator 109 adjusts the amplitude component of the input signal including the distortion component input from the output circuit 108. Then, the first variable attenuator 109 outputs an input signal including a distortion component whose amplitude component is adjusted to the first variable phase shifter 110.

  The first variable phase shifter 110 adjusts the phase component of the input signal including the distortion component input from the first variable attenuator 109. Then, the first variable phase shifter 110 outputs an input signal including a distortion component obtained by adjusting the phase component to the first combiner 111.

  The first combiner 111 extracts and extracts the distortion component by combining the input signal input from the second delay circuit 105 and the input signal including the distortion component input from the first variable phase shifter 110. The distortion component is output to the second variable attenuator 112.

  The second variable attenuator 112 adjusts the amplitude component of the distortion component input from the first combiner 111 and outputs it to the second variable phase shifter 113.

  The second variable phase shifter 113 adjusts the phase component of the distortion component input from the second variable attenuator 112 and outputs it to the frequency adjustment circuit 114.

  The frequency adjustment circuit 114 adjusts the amount of change in amplitude and the amount of change in phase according to the frequency characteristics, thereby suppressing the distortion component having an unbalanced level for each frequency generated when the amplifier 12 amplifies. The level for each frequency of the distortion component input from the phase shifter 113 is set to be unbalanced. For example, the frequency adjustment circuit 114 adjusts the amount of change in amplitude and the amount of change in phase according to frequency characteristics when the input signal is composed of a frequency f1 on the low frequency side and a frequency f2 on the high frequency side. A predetermined amplitude difference or phase difference is provided between the distortion component of the low frequency side of the input signal of f1 and the distortion component of the high frequency side of the input signal of the frequency f2, and the level of the distortion component for each frequency. To be unbalanced. Then, the frequency adjustment circuit 114 outputs a distortion component in which the level for each frequency is unbalanced to the second synthesizer 115.

  The second synthesizer 115 outputs a synthesized signal obtained by synthesizing the input signal input from the first delay circuit 103 and the distortion component input from the frequency adjustment circuit 114 to the output terminal 116.

  The output terminal 116 outputs a combined signal including the distortion component input from the second combiner 115 as an output signal.

  FIG. 2 is a block diagram showing a configuration of the frequency adjustment circuit 114.

  As shown in FIG. 2, the frequency adjustment circuit 114 includes a directional coupler 201, a variable load adjustment circuit 202 capable of changing a capacity by a control voltage, and a fixed load circuit 203. A terminal 204 is an input terminal and is connected to the second variable phase shifter 113. A terminal 205 is an output terminal and is connected to the second synthesizer 115. The terminal 206 is connected to the variable load adjustment circuit 202, and the terminal 207 is connected to the fixed load circuit 203.

  Next, a distortion compensation method in the distortion compensation apparatus 100 will be described with reference to FIGS.

  When an input signal is input from the input terminal 101, the distortion compensator 100 distributes the input signal to two systems of signals by the first distributor 102. The first delay circuit 103 delays the propagation time of one of the input signals distributed to the two systems by the first distributor 102. On the other hand, the second distributor 104 further distributes the other input signal of the input signals distributed to the two systems by the first distributor 102 to the two systems of input signals.

  Next, the second delay circuit 105 delays one propagation time of the input signal distributed to the two systems by the second distributor 104. On the other hand, the input circuit 106 adjusts the input matching of the distortion generating element 107, and the distortion generating element 107 generates distortion in the input signal. The output circuit 108 adjusts the output matching of the distortion generating element 107.

  Next, the first variable attenuator 109 adjusts the amplitude component of the input signal including the distortion component, and the first variable phase shifter 110 adjusts the phase component of the input signal including the distortion component.

  Next, the first combiner 111 combines the input signal input from the second delay circuit 105 and the input signal including the distortion component input from the first variable phase shifter 110 to extract only the distortion component. .

  Next, the second variable attenuator 112 adjusts the amplitude component of the distortion component, and the second variable phase shifter 113 adjusts the phase component of the distortion component.

  Next, the frequency adjustment circuit 114 adjusts the amount of change in amplitude and the amount of change in phase according to the frequency characteristics of the input signal, thereby generating a distortion component with an unbalanced level for each frequency.

  Next, the second synthesizer 115 outputs a synthesized signal obtained by synthesizing the input signal input from the first delay circuit 103 and the signal input from the frequency adjustment circuit 114 to the output terminal 116.

  Here, when the terminals in the four directions of the directional coupler 201 in FIG. 2 are connected at 50 ohms, the amplitude characteristics between the terminals 204 and 207 of the directional coupler 201 and between the terminals 205 and 206 are shown. As shown in a and b of FIG. 3A, the amplitude characteristic is flat in the frequency band F1 from the frequency f1 to the frequency f2. Thereby, the amplitude characteristic between the terminal 204 and the terminal 205 becomes a flat passing characteristic like c of FIG.3 (b). At this time, there is no amplitude difference due to the frequency between the transmission signal of frequency f1 and the transmission signal of frequency f2. However, for example, when different capacitive capacitors or inductive inductances are connected to the terminal 206, the amplitude characteristic between the terminal 205 and the terminal 206 of the directional coupler 201 is as shown by d in FIG. In addition, the transmission characteristic has an inclination in the frequency band F1. In this case, the amplitude characteristic between the terminal 204 and the terminal 205 is as shown in e of FIG. 3D, and an amplitude difference due to the frequency characteristic between the transmission signal of the frequency f1 and the transmission signal of the frequency f2 occurs. . Note that the phase can be changed in the same manner as the amplitude.

  Further, since the variable load adjustment circuit 202 has a characteristic that the capacitance value changes according to the applied voltage, the frequency adjustment circuit 114 changes the voltage applied to the variable load adjustment circuit 202 by a control circuit (not shown), It is possible to generate an amplitude difference due to frequency characteristics between the transmission signal having the frequency f1 and the transmission signal having the frequency f2. As described above, the frequency adjustment circuit 114 has a function of correcting the amount of change in amplitude due to frequency characteristics by changing the voltage applied to the variable load adjustment circuit 202. That is, the frequency adjustment circuit 114 has the distortion component input from the second variable phase shifter 113 having the same amplitude as the unbalanced amplitude of the distortion generated in the amplifier 12 and an opposite phase to the phase of the distortion generated in the amplifier 12. Can be adjusted. By adjusting the frequency adjustment circuit 114 in this way, a residual component h5 of the input signal as shown in FIG. 12C is generated in the distortion component input from the frequency adjustment circuit 114 to the second synthesizer 115. Therefore, the signal output from the second synthesizer 115 is as shown in FIG.

  Various correction methods based on amplitude and phase frequency characteristics other than those shown in FIG. 2 exist, and it goes without saying that the present invention can be realized by using these methods. Further, it is not limited to adjusting both the frequency characteristic of the amplitude and the frequency characteristic of the phase, but it is also possible to adjust only the frequency characteristic of the amplitude and only the frequency characteristic of the phase.

  Further, by using the distortion compensation device 100 of FIG. 1 instead of the distortion compensation circuit 11 of FIG. 5, the distortion compensation device 100 and the amplifier 12 can constitute an amplification device. In this case, the composite signal including the distortion component output from the output terminal 116 of the distortion compensation apparatus 100 is amplified by the amplifier 12, so that the distortion component generated by amplifying the composite signal by the amplifier 12 is included in the composite signal. It can be suppressed with the distortion component. As a result, the amplifier 12 outputs a signal in which distortion is suppressed.

  As described above, according to the first embodiment, the frequency adjustment circuit 114 provided in the path 4 after extracting the distortion component generates a distortion component having an unbalanced level for each frequency. Distortion can be suppressed with high accuracy even within the range, distortion compensation can be performed with low power consumption, and adjustment can be facilitated.

  In the first embodiment, the frequency adjustment circuit 114 is provided in the path 4. However, the frequency adjustment circuit having the same function as the frequency adjustment circuit 114 is not limited to this, and the path 1, path 2, or path 3 is not limited thereto. The position where the frequency adjustment circuit is provided is not limited to the above-described location, and it goes without saying that the same effect can be obtained.

(Embodiment 2)
FIG. 4 is a block diagram showing a configuration of distortion compensation apparatus 400 according to Embodiment 2 of the present invention.

  As shown in FIG. 4, the distortion compensation apparatus 400 according to the second embodiment is the same as the first frequency adjustment circuit 401 except for the frequency adjustment circuit 114 in the distortion compensation apparatus 100 according to the first embodiment shown in FIG. A second frequency adjustment circuit 402, a detection circuit 403, and a control circuit 404 are added. In FIG. 4, parts having the same configuration as in FIG.

  In FIG. 4, a path from the output terminal of the first distributor 102 to the input terminal of the second synthesizer 115 via the first delay circuit 103 is defined as a path 1. A path that reaches from the output terminal of the second distributor 104 to the input terminal of the first combiner 111 via the second delay circuit 105 and the first frequency adjustment circuit 401 is defined as a path 2. In addition, the first combiner 111 passes from the output terminal of the second distributor 104 via the distortion generator circuit 125, the first variable attenuator 109, the first variable phase shifter 110, and the second frequency adjustment circuit 402. A path that reaches the input end of the first path is defined as path 3. A path from the output terminal of the first combiner 111 to the input terminal of the second combiner 115 via the second variable attenuator 112 and the second variable phase shifter 113 is defined as a path 4.

  The second delay circuit 105 delays the propagation time of the input signal input from the second distributor 104 and outputs the delayed signal to the first frequency adjustment circuit 401.

  The first frequency adjustment circuit 401 adjusts the amount of change in amplitude and the amount of change in phase due to frequency characteristics in the input signal input from the second delay circuit 105 according to the control of the control circuit 404 to adjust the first combiner. To 111. Specifically, the first frequency adjustment circuit 401 has the same level imbalance as the level imbalance of the input signal for each frequency generated when the second frequency adjustment circuit 402 performs adjustment. The amount of change in amplitude and the amount of change in phase due to frequency characteristics in the input signal input from the second delay circuit 105 are adjusted.

  The first variable phase shifter 110 adjusts the phase component of the input signal including the distortion component input from the first variable attenuator 109. Then, the first variable phase shifter 110 outputs an input signal including a distortion component obtained by adjusting the phase component to the second frequency adjustment circuit 402.

  The second frequency adjustment circuit 402 adjusts the amount of change in amplitude and the amount of change in phase according to the frequency characteristics to suppress distortion components with unbalanced levels for each frequency generated when the amplifier 12 amplifies. The distortion component input from the first variable phase shifter 110 and the level for each frequency of the input signal are set to be unbalanced. For example, the second frequency adjustment circuit 402 adjusts the amount of change in amplitude and the amount of change in phase due to frequency characteristics when the input signal is composed of a frequency f1 on the low frequency side and a frequency f2 on the high frequency side. Thus, a predetermined amplitude difference or phase difference is provided between the distortion component of the input signal of frequency f1 and the input signal of frequency f1, and the distortion component of the input signal of frequency f2 and the input signal of frequency f2, and the distortion component Make the frequency level unbalanced. The second frequency adjustment circuit 402 unbalances the level for each frequency and has an input signal that has the same amplitude and opposite phase as the input signal output from the first frequency adjustment circuit 401. The distortion component of the signal is output to the first synthesizer 111.

  The first synthesizer 111 extracts and extracts a distortion component by synthesizing the input signal input from the first frequency adjustment circuit 401 and the input signal including the distortion component input from the second frequency adjustment circuit 402. The distorted component is output to the second variable attenuator 112 and the detection circuit 403.

  The detection circuit 403 detects the level of the input signal component remaining in the distortion component input from the first combiner 111, and outputs the detection result to the control circuit 404.

  The control circuit 404 controls the first frequency adjustment circuit 401 based on the detection result input from the detection circuit 403. Specifically, the control circuit 404 adjusts the amount of change in amplitude or phase in the first frequency adjustment circuit 401 so that the level of the remaining input signal component detected by the detection circuit 403 is minimized. Control.

  Next, a distortion compensation method in the distortion compensation apparatus 400 will be described with reference to FIG.

  When the input signal is input from the input terminal 101, the distortion compensator 400 distributes the input signal to the two systems of signals by the first distributor 102. The first delay circuit 103 delays the propagation time of one of the input signals distributed to the two systems by the first distributor 102. On the other hand, the second distributor 104 further distributes the other input signal of the input signals distributed to the two systems by the first distributor 102 to the two systems of input signals.

  Next, the second delay circuit 105 delays one propagation time of the input signal distributed to the two systems by the second distributor 104. On the other hand, the input circuit 106 adjusts the input matching of the distortion generating element 107, and the distortion generating element 107 generates distortion in the input signal. The output circuit 108 adjusts the output matching of the distortion generating element 107.

  Next, the first variable attenuator 109 adjusts the amplitude component of the input signal including distortion, and the first variable phase shifter 110 adjusts the phase component of the input signal including distortion.

  Next, the first frequency adjustment circuit 401 adjusts the amount of change in amplitude and the amount of change in phase due to frequency characteristics in the input signal input from the second delay circuit 105 according to the control of the control circuit 404. An input signal having the same unbalanced level as the input signal having an unbalanced level for each frequency output from the second frequency adjusting circuit 402 is generated. In addition, the second frequency adjustment circuit 402 adjusts the amplitude change amount and the phase change amount due to the frequency characteristics in the input signal including the distortion component input from the first variable phase shifter 110, so that the amplifier 12 In order to suppress a distortion component having an unbalanced level for each frequency generated during amplification, a distortion component and an input signal having an unbalanced level for each frequency are generated.

  Next, the first combiner 111 combines the input signal input from the first frequency adjustment circuit 401 and the input signal including the distortion component input from the second frequency adjustment circuit 402 to extract the distortion component. .

  Next, the second variable attenuator 112 adjusts the amplitude component of the distortion component, and the second variable phase shifter 113 adjusts the phase component of the distortion component.

  Next, the second synthesizer 115 outputs a synthesized signal obtained by synthesizing the input signal input from the first delay circuit 103 and the distortion component input from the second variable phase shifter 113 to the output terminal 116.

  On the other hand, the detection circuit 403 detects the level of the input signal component remaining in the distortion component input from the first combiner 111, and the control circuit 404 minimizes the level of the signal detected by the detection circuit 403. Thus, the first frequency adjustment circuit 401 is controlled.

  As described above, according to the second embodiment, an input signal having the same unbalanced level as the input signal having an unbalanced level for each frequency, which is generated when a distortion component having an unbalanced level for each frequency is generated. And distortion components are extracted, so that distortion can be accurately suppressed within a wide band and within a wide dynamic range, distortion compensation can be achieved with low power consumption, and adjustment can be facilitated. . Further, according to the second embodiment, the residual amount of the input signal in the extracted distortion component is detected so that the level of the residual portion of the detected input signal is minimized. Decline can be prevented.

  The amplification device 1 to which the distortion compensation device 100 of the first embodiment and the distortion compensation device 400 of the second embodiment are applied instead of the distortion compensation circuit 11 of FIG. 5 is a communication device such as a communication terminal device and a base station device. Can be applied to. In this case, the amplified signal output from the output terminal 13 is transmitted from the communication device as a transmission signal.

  The distortion compensation apparatus, the amplification apparatus, and the distortion compensation method according to the present invention are particularly suitable for suppressing intermodulation distortion caused by nonlinearity of input / output characteristics of a high-frequency amplifier circuit.

The block diagram which shows the structure of the distortion compensation apparatus which concerns on Embodiment 1 of this invention. The block diagram which shows the structure of the frequency adjustment circuit which concerns on Embodiment 1 of this invention. The figure which shows the amplitude phase characteristic of the directional coupler used for the frequency adjustment circuit which concerns on Embodiment 1 of this invention. The block diagram which shows the structure of the distortion compensation apparatus which concerns on Embodiment 2 of this invention. The figure which shows the structure of the conventional amplifier A vector representation of the signal in a conventional distortion compensation device Block diagram showing the configuration of a conventional distortion compensation device A vector representation of the signal in a conventional distortion compensation device The figure which shows the amplitude phase characteristic in the signal of the conventional distortion compensation circuit A vector representation of the signal in a conventional distortion compensation device The figure which shows the amplitude phase characteristic in the signal of the conventional distortion compensation circuit A vector representation of the signal in a conventional distortion compensation device A vector representation of the signal in a conventional distortion compensation device

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Distortion compensation apparatus 101 Input terminal 102 1st divider | distributor 103 1st delay circuit 104 2nd divider | distributor 105 2nd delay circuit 106 Input circuit 107 Distortion generating element 108 Output circuit 109 1st variable attenuator 110 1st 1 variable phase shifter 111 first synthesizer 112 second variable attenuator 113 second variable phase shifter 114 frequency adjustment circuit 115 second synthesizer 125 distortion generation circuit

Claims (7)

First distribution means for distributing an input signal composed of a plurality of frequencies to two systems of a first signal and a second signal;
Second distribution means for further distributing the second signal into two systems of a third signal and a fourth signal;
Distortion generating means for generating a distortion component in the fourth signal;
First synthesizing means for extracting the distortion component by synthesizing the fourth signal and the third signal which include the distortion component and have the same amplitude and opposite phase as the third signal;
Frequency adjusting means for adjusting the level for each frequency of the distortion component extracted by the first synthesis means by adjusting the amplitude or phase of the distortion component extracted by the first synthesis means;
Second synthesizing means for synthesizing the first signal and a distortion component whose level is unbalanced by the frequency adjusting means;
A distortion compensation apparatus comprising: First distribution means for distributing an input signal composed of a plurality of frequencies to two systems of a first signal and a second signal;
Second distribution means for further distributing the second signal into two systems of a third signal and a fourth signal;
Distortion generating means for generating a distortion component in the fourth signal;
By adjusting the amplitude or phase of the third signal and the fourth signal including the distortion component, the level for each frequency of the distortion component is unbalanced, and the third signal and the fourth signal are mutually connected. Frequency adjusting means having the same amplitude and opposite phase;
First combining means for extracting the distortion component by combining the third signal adjusted by the frequency adjusting means and the fourth signal including the distortion component;
Second combining means for combining the first signal and the distortion component extracted by the first combining means;
Level detection means for detecting the level of the input signal component remaining in the distortion component extracted by the first synthesis means;
Control means for controlling the amount of adjustment when adjusting the amplitude or phase in the frequency adjusting means so that the detected level is minimized;
A distortion compensation apparatus comprising: First distribution means for distributing an input signal composed of a plurality of frequencies to two systems of a first signal and a second signal;
Second distribution means for further distributing the second signal into two systems of a third signal and a fourth signal;
Distortion generating means for generating a distortion component in the fourth signal;
First synthesizing means for extracting the distortion component by synthesizing the fourth signal and the third signal which include the distortion component and have the same amplitude and opposite phase as the third signal;
Frequency adjusting means for adjusting the level for each frequency of the distortion component extracted by the first synthesis means by adjusting the amplitude or phase of the distortion component extracted by the first synthesis means;
Second combining means for generating a combined signal including a distortion component by combining the first signal and a distortion component whose level is unbalanced by the frequency adjusting means;
Amplifying means for amplifying the combined signal and suppressing distortion components generated during the amplification with distortion components included in the combined signal;
An amplification device comprising: First distribution means for distributing an input signal composed of a plurality of frequencies to two systems of a first signal and a second signal;
Second distribution means for further distributing the second signal into two systems of a third signal and a fourth signal;
Distortion generating means for generating a distortion component in the fourth signal;
By adjusting the amplitude or phase of the third signal and the fourth signal including the distortion component, the level for each frequency of the distortion component is unbalanced, and the third signal and the fourth signal are mutually connected. Frequency adjusting means having the same amplitude and opposite phase;
First combining means for extracting the distortion component by combining the third signal adjusted by the frequency adjusting means and the fourth signal including the distortion component;
Second combining means for generating a combined signal including a distortion component by combining the first signal and the distortion component extracted by the first combining means;
Level detection means for detecting the level of the input signal component remaining in the distortion component extracted by the first synthesis means;
Control means for controlling the amount of adjustment when adjusting the amplitude or phase in the frequency adjusting means so that the detected level is minimized;
Amplifying means for amplifying the combined signal and suppressing distortion components generated during the amplification with distortion components included in the combined signal;
An amplification device comprising:   A communication apparatus comprising the amplifying apparatus according to claim 3. Distributing an input signal composed of a plurality of frequencies to two systems of a first signal and a second signal;
Further distributing the second signal to two systems of a third signal and a fourth signal;
Generating a distortion component in the fourth signal;
Extracting the distortion component by combining the fourth signal and the third signal, which include the distortion component and have the same amplitude and opposite phase as the third signal;
Adjusting the amplitude or phase of the extracted distortion component to unbalance the level of the extracted distortion component for each frequency;
Generating a composite signal including a distortion component by combining the first signal and the distortion component having an unbalanced level;
Amplifying the combined signal and suppressing distortion components generated during the amplification with distortion components included in the combined signal;
A distortion compensation method comprising: Distributing an input signal composed of a plurality of frequencies to two systems of a first signal and a second signal;
Further distributing the second signal to two systems of a third signal and a fourth signal;
Generating a distortion component in the fourth signal;
By adjusting the amplitude or phase of the third signal and the fourth signal including the distortion component, the level for each frequency of the distortion component is unbalanced, and the third signal and the fourth signal are mutually connected. Having the same amplitude and opposite phase;
Extracting the distortion component by combining the adjusted third signal and the fourth signal including the distortion component;
Generating a composite signal including a distortion component by combining the first signal and the extracted distortion component;
Detecting a level of an input signal component remaining in the extracted distortion component;
Controlling an adjustment amount when adjusting the amplitude or the phase so that the detected level is minimized;
Amplifying the combined signal and suppressing distortion components generated during the amplification with distortion components included in the combined signal;
A distortion compensation method comprising:

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