JP2003318663A - Distortion compensating amplifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distortion compensating amplifier that can accurately compensate distortion, using a simple circuit configuration. <P>SOLUTION: The distortion compensating amplifier comprises an amplifier 3, where an amplified output signal may contain a distortion component; a level determining means L for judging whether the amplitude of an input signal is equal to or less than a specific value; a first detecting means 5 for detecting the amplitude of the input signal; a second detecting means 6 for detecting the amplitude of the output signal; an amplitude control means 2 that is inserted into the front stage of the amplifier for connection and controls the amplitude of a signal, that is introduced to the amplifier so that the difference or the ratio of the amplitude detected by the first and second detection means converges; and an amplitude control signal retention means SH for retaining an amplitude control signal, according to the determined output signal from the level determining means. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to, for example, broadcasting equipment,
The present invention relates to a mechanism capable of reducing a distortion component generated at the time of amplification in a power amplifier of a communication device or the like.

[0002]

2. Description of the Related Art In the field of electronic communication, an amplifier having good characteristics (linearity) over a wide frequency band is required. Therefore, various distortion compensation methods have been conventionally used to prevent output distortion of the amplifier.

As a conventional distortion compensation method, a predistortion method, a feedforward method, a LinkAMP method are used.
The method etc. are known. The pre-distation method is a method in which the input signal has a reverse distortion with respect to the distortion in the final-stage amplifier and is input to the final-stage amplifier.
The feed-forward method is a method in which an amplifier output signal is compared with an input signal to extract a distortion component, a signal representing the distortion component is accurately reverse-phase amplified, and is superimposed on the amplifier output. The LincAMP method is a method in which an input signal is branched into two signals of constant amplitude that represent the phase component thereof, and the phases of these constant amplitude signals are controlled and then combined. This L
In the incAMP method, both amplitude and phase can be processed in the video frequency band, so a constant amplitude amplifier can be used in the saturation region, and the above two signals can be generated using an oscillator, resulting in an inexpensive and simple circuit configuration. .

[0004]

Each of the conventional systems has the following problems. (1) In the predistation method, it is difficult to generate a signal that accurately cancels the distortion of the amplifier. Further, since the electronic circuit has a temperature change and a secular change, it is difficult to stably compensate the distortion of the amplifier in consideration of these changes. (2) In the feed-forward method, when the amplifier distortion is reversed-phase amplified and superposed on the amplifier output, the phase of the carrier signal must match the phase of the input signal, which makes phase control complicated. . In addition, it may be necessary to inject a pilot signal in order to accurately and automatically track various variations such as the phase and amplitude of the carrier signal. Therefore, the configuration of the device adopting this method becomes complicated. Further, there is a problem that insertion loss occurs in the power combiner when the signal amplified by the reverse phase is superposed on the output of the amplifier. (3) The LinkAMP system has an essential problem that a loss of 3 dB occurs when two signals are combined.

An object of the present invention is to provide a distortion compensating / amplifying device capable of accurately compensating for distortion after amplification with a simple circuit configuration.

[0006]

A first distortion compensation amplification apparatus of the present invention which solves the above problems is an amplifier which may include a distortion component in an amplified output signal and an input signal to be amplified. The first detection means for detecting the amplitude, the second detection means for detecting the amplitude of the output signal of the amplifier, and the difference or ratio of the amplitudes detected by the first detection means and the second detection means Amplitude control means for controlling the amplitude of the signal introduced into the amplifier so as to converge. The amplitude control means includes a variable gain amplifier that amplifies the input signal in a preceding stage of the amplifier, and a determination circuit that determines whether the amplitude of the input signal is equal to or less than a predetermined reference value, and the amplitude of the input signal is When the determination circuit determines that the state has changed from the first state in which the reference value is exceeded to the second state in which the reference value is less than or equal to the reference value, the gain of the variable gain amplifier is set to the gain in the first state. It is something to maintain.

In the second distortion compensation amplification apparatus of the present invention, the first detection means in the first distortion compensation amplification apparatus not only simply detects the amplitude of the input signal but also detects the amplitude of the input signal. Of the output signal, and the second detecting means not only simply detects the amplitude of the output signal, but also detects the amplitude of the output signal in synchronization with the phase of the input signal. It is a modified version.

The third distortion compensation amplification device of the present invention does not detect the second detection means in the second distortion compensation amplification device by synchronizing the amplitude of the output signal with the phase of the input signal. This is modified so that the amplitude of the output signal is detected in synchronization with the phase of the output signal.

According to a fourth distortion compensation amplification apparatus of the present invention, the first distortion compensation amplification apparatus detects a phase difference between the input signal and the output signal by a phase difference detection means and the phase difference detection means. And phase control means for controlling the phase of the signal introduced into the amplifier so that the values converge. The phase control means includes a phase shifter that changes the phase of a signal introduced into the amplifier, and a second state in which the amplitude of the input signal exceeds the reference value and is equal to or less than the reference value. When the determination circuit determines that the phase has changed to, the phase shifter is controlled to maintain the phase in the first state.

In the fifth distortion compensation amplification device of the present invention, the first detection means in the fourth distortion compensation amplification device not only simply detects the amplitude of the input signal, but also detects the amplitude of the input signal. Of the output signal, and the second detecting means not only simply detects the amplitude of the output signal, but also detects the amplitude of the output signal in synchronization with the phase of the input signal. It is a modified version.

The sixth distortion compensation amplification device of the present invention does not detect the second detection means in the fifth distortion compensation amplification device by synchronizing the amplitude of the output signal with the phase of the input signal. This is modified so that the amplitude of the output signal is detected in synchronization with the phase of the output signal.

The first to sixth distortion compensating amplifiers of the present invention may further include delay means for delaying the input signal according to the output timing of the output signal. This facilitates phase synchronization. From the viewpoint of facilitating phase synchronization, a limiter for limiting the amplitude of at least one of the input signal and the output signal to a predetermined value before phase synchronization, and / or the input signal and the output The distortion compensating amplifier is further provided with a phase shifter for changing the phase of at least one of the signals. Preferably, the amplitude control means is configured to control the amplitude of the signal introduced into the amplifier so that the amplitude of the output signal has a linear ratio to the amplitude of the input signal.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> A first embodiment of a distortion compensation amplification apparatus to which the present invention is applied will be described. The distortion compensation amplification device of this embodiment is roughly divided into an amplification section and a distortion compensation section.

As shown in FIG. 1, the amplifier unit receives the input signal Pi input from the input terminal from the first branch circuit (CDC1).
1 is input to and amplified by the variable gain amplifier (VG-AMP) 2, and the amplitude of the signal amplified by the variable gain amplifier 2 is amplified by the amplifier (AMP) 3 to a predetermined level. The transmission output signal Po is configured to be output from the output end to an external circuit via the second branch circuit (CDC2) 4. The amplifier 3 may include a distortion component in the amplified output signal.

The distortion compensator is a first detector (DE) for detecting the amplitude of the branch signal S1 extracted from the first branch circuit 1.
T1) 5, the branch signal S extracted from the second branch circuit 4
A second detector (DET2) 6 for detecting the amplitude of 2, a first
And the branch signals S1 output from the second detectors 5 and 6.
An operational amplifier (OP-AMP) 7 that performs operational amplification of the difference value of the amplitude of S2 and outputs a gain control signal for controlling the gain of the variable gain amplifier 2 is provided as its basic configuration. The variable gain amplifier 2 dynamically changes the gain according to the amplitude of the gain control signal.

By configuring the distortion compensator in this way, a signal feedback loop is formed from the output side to the input side of the amplifier 3, and the difference value of the amplitudes of the branch signal S1 and the branch signal S2 is set to a zero value or a predetermined value. Will converge to. Branch signal S1
Is proportional to the amplitude of the input signal Pi, and the amplitude of the branch signal S2 is proportional to the amplitude of the transmission output signal Po. These relationships are expressed by the following equations. C1 = Pi / S1, C2 = Po / S2 (1) where C1 and C2 are coefficients. Although it depends on the specifications of the operational amplifier 7, normally, the above-mentioned coefficients C1 and C are set so that the difference between the amplitudes of the branch signals S1 and S2 or the ratio of the amplitudes becomes a predetermined value.
Predetermine 2. The difference in amplitude is set to, for example, a zero value or a predetermined offset value, and the amplitude ratio is set to, for example, about "1". If the gain of the operational amplifier 7 is sufficiently large,
The difference in amplitude between the branch signals S1 and S2 is quickly converged to a predetermined value. If this value is zero, S1 = S2
Therefore, the relationship of the above equation (1) is expressed by equations (2) and (3). Pi / C1 = Po / C2 ... (2) Po = Pi * C2 / C1 ... (3)

From the equation (3), the transmission output signal Po becomes C2 / C1 times as large as the input signal Pi, and this distortion compensation amplifying device exhibits linearity with respect to amplitude (the operational amplifier 7 is
That way the input signal is amplified). Therefore, it is possible to output at least a low distortion signal related to the amplitude of the transmission output signal Po.

However, when the input signal is very small and the amplitude variation width between the input and output signals is large, particularly when the amplitude also becomes zero, it is affected by the offset voltage of the operational amplifier 7, etc. Amplitude / phase detection error increases,
It is also expected that the characteristics of the above feedback loop become abnormal. In this state, if the feedback loop is closed, the distortion of the output signal will increase. Therefore, in this embodiment, in addition to the basic configuration described above, a level determination circuit L for determining the amplitude of the branch signal S1 and a gain control signal to be input to the variable gain amplifier 2 based on the determination result of the level determination circuit L. A sample / hold circuit SH for controlling the level is provided.

The sample / hold circuit SH is a circuit for selectively performing sampling and holding. In the present embodiment, as a result of the level judgment circuit L judging the sample / hold circuit SH, the amplitude of the branch signal S1 is changed. If it is less than the predetermined reference value, the voltage amplitude of the gain control signal is held at the value immediately before the feedback loop, while if it is greater than the reference value, the voltage amplitude of the gain control signal is adjusted to the feedback loop. The signal output from the operational amplifier 7 is output as it is, regardless of the immediately preceding value.

In this embodiment, the level judgment circuit L
The reason why the sample / hold circuit SH is provided is as follows. During normal operation, that is, when the amplitude of the input signal is small, the amplitude of the output signal is small, and conversely, when the amplitude of the input signal is large, the amplitude of the output signal is correspondingly large (first state). ), The amplitude difference between the input and output signals does not become large unless the gains (loop gains) of the amplifier 3 and the variable gain amplifier 2 are largely deviated. If the loop gain at this time is held, the problem of distortion does not occur. Therefore, in the present embodiment, the level determination circuit L determines whether or not the amplitude of the input signal is less than or equal to a reference value (value when distortion becomes a practical problem), and the amplitude is less than or equal to the reference value (second state). If it changes to, the amplitude of the gain control signal immediately before the change is changed to the sample / hold circuit SH.
It was made to hold by. When the amplitude of the input signal is recovered to exceed the reference value, the operation of the sample / hold circuit SH is restored so that the feedback loop operates normally, and the signal output from the operational amplifier 7 is directly used as the gain control signal. To be By doing so, even when the amplitude of the input signal is very small in a certain loop period and the amplitude difference from the output signal becomes large, when the gain of the variable gain amplifier 2 is normal, that is, the input Since the gain is when the amplitude of the signal exceeds the reference value, the circuit operates normally.

As described above, in the distortion compensating amplifier of the first embodiment, even when the branch signal S1, that is, the input signal Pi changes to the reference value or less, the loop gain just before the change remains. , The performance of distortion compensation can be maintained regardless of the amplitude of the input signal Pi.

<Second Embodiment> A second embodiment of the distortion compensation amplification apparatus will be described with reference to FIG. The distortion compensating amplifier according to this embodiment has a first synchronous detector 15 and a second synchronous detector 16 in place of the first and second detectors 5 and 6 of the first embodiment shown in FIG. Is used. The same components as those shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, the limiter 12 limits the signal S1 output from the first branch circuit 1 to a constant amplitude and outputs it to the synchronous detector 15 and the synchronous detector 16. The phase shifter 13 adjusts the phase of the branch signal S1 to a predetermined magnitude and outputs it to the synchronous detector 15. The synchronous detector 15 detects the amplitude of the branch signal S1 in synchronization with the phase of the signal of the limiter 12, and outputs the detection result to the operational amplifier 7.
The phase shifter 14 adjusts the phase of the branch signal S2 to a predetermined magnitude and outputs it to the synchronous detector 16. The synchronous detector 16 is
The phase of the signal output from the phase shifter 14 is synchronized with the phase of the signal of the limiter 12 to detect the amplitude of the branch signal S2,
The detection result is output to the operational amplifier 7.

In the distortion compensating amplifier of this embodiment, since the synchronous detectors 15 and 16 are used, the frequency range and amplitude range (dynamic range) of the signal to be detected should be made wider than that of a detector such as a diode. You can Further, the outputs of the phase shifters 13 and 14 are adjusted to adjust the synchronous detector 1
It can be adjusted so that the outputs of 5 and 16 are maximized. Further, since the limiter 12 limits the branch signal S1 to a constant amplitude, the synchronous detection is performed.
Synchronous detection of the branch signals S1 and S2 becomes easy.

<Third Embodiment> A third embodiment of the distortion compensation amplifier apparatus will be described with reference to FIG. In this embodiment, in addition to the configuration of the first embodiment shown in FIG. 1, phase shifters 8 and 9, a phase detector 10 for controlling the phase shifter 8 and an operational amplifier (OP-AMP) 11 are provided. , A sample / hold circuit SH2 is provided. The phase shifter 8 adjusts the phase of the signal output by the variable gain amplifier 2 based on the phase control signal, and outputs the adjusted signal to the amplifier 3. Among the other constituent elements, the same constituent elements as those shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

The phase detector 10 detects the phase difference value between the branch signal S1 extracted from the first branch circuit 1 and the second branch signal S2 extracted from the second branch circuit 4 via the phase shifter 9. Then, the phase difference detection signal of the voltage amplitude corresponding to the difference value is output to the operational amplifier 11. Operational amplifier 11
Outputs the phase control signal for controlling the phase shift amount of the phase shifter 8 by amplifying the phase difference detection signal of the phase detector 10. When the amplitude of the branch signal S1 exceeds the reference value (first state) as a result of the determination by the level determination circuit L, the sample / hold circuit SH2 outputs the voltage of the phase control signal output from the operational amplifier 11. The amplitude is output to the phase shifter 8 as it is. On the other hand, when the amplitude of the branch signal S1 is changing to the state of being equal to or lower than the reference value (second state), immediately before the change (first state)
The voltage amplitude of the output phase control signal (in the state) is held, and the phase control signal having the held voltage amplitude is output to the phase shifter 8.

In this embodiment, the phase shifter 9
Is an output of the operational amplifier 11 when the line between the operational amplifier 11 and the phase shifter 8 is disconnected when the total phase of the variable gain amplifier 2, the phase shifter 8 and the amplifier 3 has a finite value. The phase of the branch signal S2 is adjusted so that the value becomes a value.

In this embodiment, the phase detector 10 detects the phase difference between the output signal and the input signal, and the operational amplifier 1
Since 1 outputs a phase control signal having a voltage amplitude corresponding to this phase difference to the phase shifter 8, it is possible to compensate the phase distortion of the output signal by the amplifier 3 and the like with a simple circuit configuration. Further, a level determination circuit L is provided in the subsequent stage of the first branch circuit 1, and a sample / hold circuit SH2 controlled according to the determination result of the level determination circuit L is provided between the phase shifter 8 and the operational amplifier 11. When the branch signal S1, that is, the input signal Pi changes below the reference value, the voltage amplitude of the phase control signal immediately before the change is held (that is, the phase of the phase shifter 8 changes to the value immediately before the change). Hold), the distortion compensation performance can be maintained even when the input signal Pi is very small.

Further, a phase shifter 9 is arranged to adjust the phase of the branch signal S2 so that the output of the operational amplifier 11 becomes, for example, zero value when the phase distortion of the output signal is converged, and the phase detector Since only the phase variation due to the amplitude variation of the input signal is detected at 10 and the phase shifter 8 is controlled by this, the compensation amount by the phase shifter 8 can be minimized.

In this embodiment, the example in which the phase shifter 8 is arranged at the subsequent stage of the variable gain amplifier 2 has been described.
The variable gain amplifier 2 may be arranged after the phase shifter 8 by reversing this arrangement.

<Fourth Embodiment> A fourth embodiment of the distortion compensation amplifier apparatus will be described with reference to FIG. In this embodiment, instead of the wave detector 5 and the wave detector 6 in the third embodiment, the synchronous detection means in the second embodiment is arranged. The same components as those in FIGS. 2 and 3 are designated by the same reference numerals, and the description thereof will be omitted. According to this embodiment, the limiter 12 and the phase shifter 1 shown in the second embodiment are used.
Since 3, 14 and the synchronous detectors 15, 16 are provided, the same effect as that of the second embodiment can be obtained in addition to the effect of the third embodiment.

<Fifth Embodiment> A fifth embodiment of the distortion compensation amplifier apparatus will be described with reference to FIGS.
In this embodiment, in addition to the configuration of each of the above-described embodiments shown in FIGS. 1 to 4, the delay circuit 1 is provided at the subsequent stage of the first branch circuit 1.
7 is provided, and the delay circuit 17 delays the output S1 of the first branch circuit 1 for a predetermined time and outputs it. The same components as those shown in FIGS. 1 to 4 are designated by the same reference numerals, and the description thereof will be omitted.

When amplifying the input signal, a temporal shift occurs between the branch signal S2 and the branch signal S1 due to the amplifier 3 or the like. According to this embodiment, the delay circuit 17 causes the first branch circuit 1 to operate. By delaying the output S1 by the time delay of the operational amplifier 3, this time shift can be eliminated. In particular, in the high frequency band, the difference voltage due to this time shift may increase and the delay time of the loop may worsen the condition of the wide band, but by disposing the delay circuit 17, the shift due to these time delays may occur. It can be solved reliably.

<Sixth Embodiment> A sixth embodiment of the distortion compensation amplifier apparatus will be described with reference to FIG. This embodiment is a modification of the second embodiment shown in FIG. Figure 2
The same components as those shown in are attached with the same notations and an explanation thereof will be omitted. In this embodiment, the limiter 18 limits the amplitude of the branch signal S1 to a constant amplitude and outputs it to the first synchronous detector 22. Phase shifter 20
Adjusts the phase of the branch signal S1 to a predetermined magnitude and outputs it to the synchronous detector 22. The synchronous detector 22 is the phase shifter 20.
The phase of the signal output from is synchronized with the phase of the output signal of the limiter 18, the amplitude of the branch signal S1 is detected, and the detection signal obtained by this is output to the operational amplifier 7.

The limiter 19 limits the amplitude of the branch signal S2 to a constant amplitude and outputs it to the second synchronous detector 23. The phase shifter 21 adjusts the phase of the branch signal to a predetermined magnitude and outputs it to the synchronous detector 23. The synchronous detector 23 is
The phase of the signal output from the phase shifter 21 is synchronized with the phase of the output signal of the limiter 19, the amplitude of the branch signal S2 is detected, and the detection signal obtained by this is output to the operational amplifier 7. The operational amplifier 7 amplifies the differential voltage between the detection signals of the synchronous detector 22 and the synchronous detector 23 and outputs it to the variable gain amplifier 2 as an amplitude control signal to dynamically change the gain of the variable gain amplifier 2. Let

In the configuration of the second embodiment shown in FIG. 2 above, the second synchronous detector 16 detects the variable gain amplifier 2 by synchronizing the phase of the branch signal S2 with the amplitude of the branch signal S1. When the phase change of the amplifier 3 is large, the detection output of the synchronous detector 16 may change. According to the configuration of this embodiment, since the second synchronous detector 23 detects the amplitude of the branch signal S2 in synchronization with the phase of the branch signal S2, the synchronization by phase fluctuations by the variable gain amplifier 2 and the amplifier 3 is performed. It is possible to reliably suppress fluctuations in the detection output of the detector 23.

<Seventh Embodiment> A seventh embodiment of the distortion compensation amplifier apparatus will be described with reference to FIG. This embodiment is an embodiment in which a phase shifter 8, a phase shifter 9, a phase detector 10, and an operational amplifier 11 of the fourth embodiment (FIG. 4) are added to the configuration of the sixth embodiment. The same components as those shown in FIGS. 9 and 4 are designated by the same reference numerals, and the description thereof will be omitted. Also in this embodiment, since the second synchronous detector 23 detects the amplitude of the branch signal S2 in synchronization with the phase of the branch signal S2, the second synchronous detector 23 performs synchronous detection due to phase fluctuations by the variable gain amplifier 2 and the amplifier 3. The fluctuation of the detection output of the device 23 can be surely suppressed.

<Eighth Embodiment> An eighth embodiment of the distortion compensation amplifier apparatus will be described with reference to FIGS. 11 and 12. In this embodiment, a delay circuit 24 is provided in addition to the configurations of the sixth and seventh embodiments, and the branch signal S1 is delayed by this delay circuit 24 for a predetermined time to limit the limiter 18 and the phase shifter 2.
0, which is output to the phase detector 10.
The time delay of the branch signal S2 occurs due to the amplifier 3 or the like,
By delaying the branch signal S1 by the delay circuit 24 by the above-mentioned time delay, the time lag caused by the amplifier 3 or the like can be eliminated. In particular, in the high frequency band, the difference voltage due to this time shift becomes large and the condition of the wide band becomes worse due to the delay time of the loop, but by disposing the delay circuit 24, the shift due to these time delays can be eliminated. it can.

As described in detail above, according to each embodiment, since the variable gain amplifier 2 and the phase shifter 8 for controlling the amplitude are arranged in the preceding stage of the amplifier 3, the distortion of the amplifier as in the feed-forward system. When the signal is inverted in phase and superposed on the output of the amplifier, a configuration for matching the phase of the carrier signal with the phase of the input signal is unnecessary, and accurate distortion compensation can be performed with a simple circuit configuration.

Further, in each embodiment, since there is only the second branch circuit 4 which is the signal extracting means after the final stage amplifier,
It does not cause a large loss and is advantageous in terms of power efficiency. Further, since a circuit for generating a pilot signal and a filter for removing the pilot signal as in the case of the LinCAMP system are not necessary, an inexpensive and simple circuit configuration can be obtained. Furthermore, if the amplitude fluctuation range between the input and output signals is large (such as when the input signal becomes weak), the loop may become abnormal, especially for signals that include zero amplitude of the input signal. However, since the loop gain or phase shift during normal operation is maintained, it is possible to suppress deterioration of the distortion compensation characteristic at a small amplitude.

According to the present invention, the function of distortion compensation becomes stable even for a modulated wave having a very wide amplitude change width.
In a transmission device that transmits various modulated signals, linearity of a transmission power amplifier is generally required. In order to satisfy this requirement, conventionally, the power amplifier for transmission is used in a region close to saturation, so that the power consumption is several times as high as the transmission output.
However, by using the distortion compensation amplification device of the present invention for the transmission power amplifier, it becomes possible to suppress power consumption while maintaining linearity.

[0042]

As is apparent from the above description, according to the present invention, it is possible to realize a low power distortion compensating and amplifying device capable of accurately compensating for distortion with a simple circuit structure with a simple structure. Can be played.

[Brief description of drawings]

FIG. 1 is a diagram showing a distortion compensation amplification device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

FIG. 3 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

FIG. 4 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

FIG. 5 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

FIG. 6 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

FIG. 7 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

FIG. 8 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

FIG. 9 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

FIG. 10 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

FIG. 11 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

FIG. 12 is a diagram showing a distortion compensation amplification device according to another embodiment of the present invention.

[Explanation of symbols]

2 Variable gain amplifier 3 amplifier 5 detector 6 detector 7 Operational amplifier 8 Phase shifter 9 Phase shifter 10 Phase detector 11 Operational amplifier 13 Phase shifter 14 Phase shifter 15 Synchronous detector 16 Synchronous detector 20 Phase shifter 21 Phase shifter 22 Synchronous detector 23 Synchronous detector L level judgment circuit SH, SH2 sample / hold circuit

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5J090 AA01 AA41 CA21 FA20 GN02                       KA00 KA01 KA15 KA16 KA19                       KA20 KA55 MA20 SA13 TA01                 5J500 AA01 AA41 AC21 AF20 AK00                       AK01 AK15 AK16 AK19 AK20                       AK55 AM20 AS13 AT01

Claims (12)

[Claims] 1. An amplifier that may include a distortion component in an amplified output signal, a first detecting unit that detects an amplitude of an input signal to be amplified, and an amplitude of an output signal of the amplifier. Second detection means and amplitude control means for controlling the amplitude of the signal introduced into the amplifier so that the difference or ratio of the amplitudes detected by the first detection means and the second detection means converges. The amplitude control means includes a variable gain amplifier that amplifies the input signal in a preceding stage of the amplifier, and a determination circuit that determines whether or not the amplitude of the input signal is less than or equal to a predetermined reference value. When the determination circuit determines that the amplitude has changed from the first state in which the amplitude exceeds the reference value to the second state in which the amplitude is less than or equal to the reference value, the gain of the variable gain amplifier is set to the value in the first state. Keep it in gain Wherein the distortion compensation amplifying apparatus. 2. An amplifier that may include a distortion component in the amplified output signal, a first detection unit that detects the amplitude of an input signal to be amplified in synchronization with the phase of the input signal, and The second detection means for detecting the amplitude of the output signal of the amplifier in synchronization with the phase of the input signal and the difference or ratio of the amplitudes detected by the first detection means and the second detection means converge. And an amplitude control means for controlling the amplitude of the signal introduced into the amplifier, wherein the amplitude control means is a variable gain amplifier for amplifying the input signal in a stage before the amplifier, and the amplitude of the input signal is predetermined. A determination circuit that determines whether the input signal is less than or equal to a reference value, and the determination circuit determines that the first state in which the amplitude of the input signal exceeds the reference value has changed to a second state that is less than or equal to the reference value. When Serial variable the gain of the gain amplifier, characterized in that to maintain the gain when the first state, the distortion compensation amplifying apparatus. 3. An amplifier which may include a distortion component in the amplified output signal, first detecting means for detecting the amplitude of the input signal to be amplified in synchronization with the phase of the input signal, and The second detection means for detecting the amplitude of the output signal of the amplifier in synchronization with the phase of the output signal and the difference or ratio of the amplitudes detected by the first detection means and the second detection means converge. And an amplitude control means for controlling the amplitude of the signal introduced into the amplifier, wherein the amplitude control means is a variable gain amplifier for amplifying the input signal in a stage before the amplifier, and the amplitude of the input signal is predetermined. A determination circuit that determines whether the input signal is less than or equal to a reference value, and the determination circuit determines that the first state in which the amplitude of the input signal exceeds the reference value has changed to a second state that is less than or equal to the reference value. When Serial variable the gain of the gain amplifier, characterized in that to maintain the gain when the first state, the distortion compensation amplifying apparatus. 4. An amplifier which may include a distortion component in the amplified output signal, a first detecting means for detecting an amplitude of an input signal to be amplified, and an amplitude of an output signal of the amplifier. Second detection means, and amplitude control means for controlling the amplitude of the signal introduced into the amplifier so that the difference or ratio of the amplitudes detected by the first detection means and the second detection means converges. The phase difference detection means detects a phase difference between the input signal and the output signal, and the phase control means controls the phase of the signal introduced into the amplifier so that the detection value by the phase difference detection means converges. The amplitude control means includes a variable gain amplifier that amplifies the input signal in a stage preceding the amplifier, and a determination circuit that determines whether the amplitude of the input signal is less than or equal to a predetermined reference value. Is the above group When it is determined by the determination circuit that the first state, which exceeds the value, changes to the second state, which is equal to or less than the reference value, the gain of the variable gain amplifier is maintained at the gain in the first state. The phase control means includes a phase shifter that changes a phase of a signal introduced into the amplifier, and a second state in which the amplitude of the input signal exceeds the reference value and is equal to or less than the reference value When the determination circuit determines that the state has changed, the first
A distortion compensating and amplifying device, characterized in that the phase shifter is controlled so as to maintain the phase in the state. 5. An amplifier which may include a distortion component in the amplified output signal, first detecting means for detecting the amplitude of the input signal to be amplified in synchronization with the phase of the input signal, and The second detection means for detecting the amplitude of the output signal of the amplifier in synchronization with the phase of the input signal and the difference or ratio of the amplitudes detected by the first detection means and the second detection means converge. Amplitude control means for controlling the amplitude of the signal introduced to the amplifier, phase difference detection means for detecting the phase difference between the input signal and the output signal, and the detection value by the phase difference detection means converges. A phase control means for controlling the phase of a signal introduced into the amplifier, wherein the amplitude control means comprises a variable gain amplifier for amplifying the input signal at a stage before the amplifier, and an amplitude of the input signal is a predetermined reference. Less than value And a determination circuit that determines whether the amplitude of the input signal has changed from a first state in which the amplitude exceeds the reference value to a second state in which the amplitude is less than or equal to the reference value. The gain of the variable gain amplifier is maintained at the gain in the first state, the phase control means includes a phase shifter that changes the phase of a signal introduced into the amplifier, and the amplitude of the input signal is the When the determination circuit determines that the first state, which exceeds the reference value, changes to the second state, which is equal to or less than the reference value, the phase shift so as to maintain the phase in the first state. Distortion compensating amplifier, characterized by controlling the device. 6. An amplifier which may include a distortion component in the amplified output signal, first detecting means for detecting the amplitude of the input signal to be amplified in synchronization with the phase of the input signal, and The second detection means for detecting the amplitude of the output signal of the amplifier in synchronization with the phase of the output signal and the difference or ratio of the amplitudes detected by the first detection means and the second detection means converge. Amplitude control means for controlling the amplitude of the signal introduced to the amplifier, phase difference detection means for detecting the phase difference between the input signal and the output signal, and the detection value by the phase difference detection means converges. A phase control means for controlling the phase of a signal introduced into the amplifier, wherein the amplitude control means comprises a variable gain amplifier for amplifying the input signal at a stage before the amplifier, and an amplitude of the input signal is a predetermined reference. Less than value And a determination circuit that determines whether the amplitude of the input signal has changed from a first state in which the amplitude exceeds the reference value to a second state in which the amplitude is less than or equal to the reference value. The gain of the variable gain amplifier is maintained at the gain in the first state, the phase control means includes a phase shifter that changes the phase of a signal introduced into the amplifier, and the amplitude of the input signal is the When the determination circuit determines that the first state, which exceeds the reference value, changes to the second state, which is equal to or less than the reference value, the phase shift so as to maintain the phase in the first state. Distortion compensating amplifier, characterized by controlling the device. 7. The distortion compensation amplification device according to claim 1, further comprising delay means for delaying the input signal in accordance with the output timing of the output signal before detecting the amplitude thereof. . 8. The distortion compensation according to claim 4, further comprising delay means for delaying the input signal in accordance with the output timing of the output signal before detecting the amplitude and phase of the input signal. Amplification device. 9. The distortion compensation according to claim 2, 3, 5 or 6, further comprising a limiter for limiting the amplitude of at least one of the input signal and the output signal before phase synchronization to a predetermined value. Amplification device. 10. The distortion compensation amplification device according to claim 4, comprising a phase shifter for changing the phase of at least one of the input signal and the output signal. 11. The distortion compensation amplification device according to claim 10, further comprising a limiter for limiting the amplitude of at least one of the input signal and the output signal before phase synchronization to a predetermined value. 12. The amplitude control means controls the amplitude of a signal introduced into the amplifier so that the amplitude of the output signal has a linear ratio to the amplitude of the input signal. Item 12. The distortion compensation amplifier device according to any one of items 1 to 11.