JP2003298361A - Power amplification method and power amplifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively remove distortions generated in a nonlinear element, such as an amplitude amplifier, when performing power amplification in a linear amplifying method for amplifying by converting an input signal to two constant amplitude signals, wherein amplitude fluctuations are converted to phase information by using a nonlinear element. <P>SOLUTION: In a power amplification method based on a linear amplification, an input signal is converted to two divided signals having constant amplitudes wherein amplitude fluctuations of the input signal are converted to phase information, and the two divided signals are amplified, composed and output as output signals. Phases of the two division signals are controlled and distortions of amplitudes of the output signals are corrected in accordance with a comparison result of the input signal and the output signal. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power amplification method and a power amplifier, and more particularly to a power amplification method and power suitable for use in configuring a high frequency power amplification device in communication equipment or broadcasting equipment. The present invention relates to an amplifier, and particularly to a power amplification method and a power amplifier suitable for use in configuring a high-efficiency and low-distortion distortion compensation amplification device.

[0002]

2. Description of the Related Art Conventionally, a power amplifier used for constructing a high frequency power amplifying device in communication equipment or broadcasting equipment is required to have low distortion and good linearity over a wide frequency band. ing. Therefore, as a technique for obtaining good linearity in a power amplifier, for example, LINC (LinearA)
mpification with Nonline
The input signal is divided into two constant-amplitude divided signals obtained by converting the amplitude fluctuations of the input signal into phase information using a non-linear element such as the ar Components) system, and the two divided signals are amplified and then combined. Then, a technique relating to distortion compensation of a power amplifier, such as a power amplification method by a linear amplification method for outputting as an output signal, has been proposed.

Here, the LINC method is a linear amplification method using a non-linear element such as an amplitude amplifier, and uses a method of amplifying a constant amplitude signal obtained by converting amplitude fluctuation into phase information.

The basic principle of the LINC system is to divide a band-pass input signal having one or both of amplitude fluctuation and phase fluctuation into two signals having a constant amplitude and a change only in phase. To amplify it. This point will be described with reference to FIG.

First, consider the bandpass signal Sa having a constant phase shown in the equation (1).

S (a) = E (t) cosω ₀ t ... Equation (1) If Em is the maximum value of E (t), then E (t) = Emsinφ (t) Equation (2) It can be expressed as.

In FIG. 1, a signal dividing section (component separator: COMPONENTS SEPARATO) is provided.
R) 100 is two constant amplitude signals S1
a, S1b are produced. Here, the following expression (3) is established.

Sa (t) = (Em / 2) [sin [ω ₀ t + φ (t)] − sin [ω ₀ t −φ (t)]] = S 1 a (t) −S 2 a (t) (3) However, S1a (t) = (Em / 2) sin [ω ₀ t + φ (t)] ... Equation (4) S2a (t) = (Em / 2) sin [ω ₀ t−φ (t )] It is Formula (5).

Therefore, G is the amplifier section 102a, 102b
And the gain of amplification at
From GS1a (t) to GS2a in the signal combining unit 104.
By subtracting (t) and combining, it is expressed as shown in Expression (6).

GSa (t) −GS1a (t) = GEmsinφ (t) cosω ₀ t = GS a (t) Equation (6) From the above, two constant amplitude angle modulation signals are obtained.
It can be seen that it is amplified by any amplifier in a sufficient band regardless of its amplitude linearity.

By the way, W-CDMA (Wideban)
d-Code Division Multiple A
In a modulation method that exhibits envelope fluctuations such as ccess), when a power amplifier based on the LINC method having the above-described principle is used, the ratio of reactive power to active power increases at the time of power combination, and It was pointed out that the decline was remarkable.

That is, in the LINC system, the power efficiency is determined by the ratio of the peak power to the average power of the input signal. The larger the ratio, the larger the reactive power, and the power efficiency deteriorates as a result. That is, in the LINC method, the amplitude information of the input signal is converted into the phase information and then divided into two constant amplitude signals by the signal division unit. However, since the signal amplitude is constant, the signal amplitude after power combination is small (input If the amplitude of the signal is small), the reactive power will increase, resulting in a decrease in power efficiency.

Reactance matching method, RF-DC power conversion method and the like have been proposed as methods for improving the power efficiency in the LINC method.

Here, the reactance matching method is
By terminating the output of the amplifier with a reactive terminator, the distortion is somewhat sacrificed, but the power efficiency is improved.

In the RF-DC power conversion method, the reactive power generated in the power combiner is RF-DC converted and fed back to the DC power source to reduce the total power loss and reduce the power efficiency of the power amplifier. It is intended to improve.

However, in the power amplifier based on the above-mentioned conventional LINC system, there is a problem that it is difficult to remove the distortion generated in the non-linear element such as the amplitude amplifier.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned various problems of the prior art, and an object thereof is to use an nonlinear element to input an input signal. When power amplification is performed by a linear amplification method in which the amplitude fluctuation of the input signal is divided into two constant-amplitude divided signals converted into phase information, the two divided signals are amplified, then combined, and output as an output signal, An object of the present invention is to provide a power amplification method and a power amplifier capable of effectively removing distortion generated in a non-linear element such as an amplitude amplifier.

[0018]

In order to achieve the above object, a power amplification method and a power amplifier according to the present invention use two elements in which an amplitude fluctuation of the input signal is converted into phase information by using a non-linear element. Split into constant amplitude split signals,
In a power amplification method or power amplifier using a linear amplification method in which the two divided signals are amplified and then combined and output as an output signal, when the input signal is divided into two divided signals by the signal dividing unit, The amplitude information is included in the two divided signals as phase information, and the amplitudes of the two divided signals forming the pair are the same, but the nonlinear element in the signal path of these two divided signals is used. When distortion is mixed in the amplitude of the divided signal due to, the distortion of the amplitude is corrected by controlling the phase of the two divided signals forming a pair, and the distortion is effectively removed. .

That is, the invention according to claim 1 of the present invention divides an input signal into two constant amplitude divided signals obtained by converting an amplitude fluctuation of the input signal into phase information using a non-linear element, In a power amplification method by a linear amplification method in which the two divided signals are amplified and then combined and output as an output signal, the phase of the two divided signals is controlled according to the comparison result of the input signal and the output signal. This is to correct the distortion of the amplitude of the output signal.

According to a second aspect of the present invention, a non-linear element is used to divide an input signal into two constant amplitude divided signals obtained by converting amplitude fluctuations of the input signal into phase information. In a power amplification method by a linear amplification method in which the two divided signals are amplified and then combined and output as an output signal, the phase of the two divided signals is controlled according to the comparison result of the input signal and the output signal. According to a first process of correcting the distortion of the amplitude of the output signal and the amplitude of the input signal,
And a second process for controlling the amplitude values of the two divided signals.

According to a third aspect of the present invention, a non-linear element is used to divide an input signal into two constant amplitude divided signals obtained by converting amplitude fluctuations of the input signal into phase information. In a power amplification method by a linear amplification method in which the two divided signals are amplified and then combined and output as an output signal, the phase of the two divided signals is controlled according to the comparison result of the input signal and the output signal. It has a first process for correcting the distortion of the amplitude of the output signal and a process for controlling the amplitude values of the two divided signals in multiple stages according to the amplitude of the envelope of the input signal. is there.

According to a fourth aspect of the present invention, a non-linear element is used to divide an input signal into two constant amplitude divided signals obtained by converting amplitude fluctuations of the input signal into phase information, In a power amplifier based on a linear amplification system that amplifies the two divided signals and then outputs them as an output signal by combining them, comparing means for comparing an input signal with an output signal, and two dividing means according to a comparison result of the comparing means. Phase control means for controlling the phase of the signal, detection means for detecting the amplitude of the envelope of the input signal, and amplitude values of the two divided signals are controlled in multiple steps according to the detection result by the detection means. Amplitude control means is provided.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of a power amplifier according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 is a block diagram showing an example of the embodiment of the power amplifier according to the present invention.

This power amplifier is a power amplifier of a linear amplification system which amplifies a constant amplitude signal obtained by converting amplitude fluctuation into phase information using a non-linear element, and frequency-converts an input signal input from the outside into an IF signal. An RF down converter 10 and an analog / digital (A / D) converter 12 for converting an input signal (IF signal) which is an analog signal output from the RF down converter 10 by analog / digital conversion (A / D conversion) into a digital signal. And A
An IQ distributor 14 that IQ-distributes the input signal A / D converted by the A / D converter 12, and a signal divider 16 that receives the input signal IQ-distributed by the IQ distributor 14.
A phase control unit 18 to which the input signal IQ-distributed by the IQ distribution unit 14 is input; and a signal division unit 16 that divides the input signal into two by converting amplitude fluctuations of the input signal into phase information. A digital / analog (D / A) converter 20 for converting each of the generated divided signals having a constant amplitude into a digital / analog (D / A) signal, and a digital signal output from the D / A converter 20. RF up-converters 22a and 22b for respectively frequency conversion, and RF up-converter 22a,
An amplifier (Amp) section 24a, 24b for amplifying the digital signal frequency-converted by 22b and an RF power combiner (R) for combining the digital signals amplified by the amplifier sections 24a, 24b and outputting them as an output signal.
A signal synthesizer 26 including an F POWER COMBINER and a coupler (COUPLER), an RF down converter 28 for frequency-converting a part of the output signal output from the coupler of the signal synthesizer 26, and an analog / digital converter (A / D). The analog / digital (A / D) converter 30 that converts the output signal, which is an analog signal output from the RF down converter 28 into a digital signal, and inputs the digital signal to the phase controller 18, is configured.

Here, FIG. 3 shows a detailed configuration of the signal division unit 16 and the phase control unit 18. The signal control unit 16 quadratures the input signal IQ-distributed by the IQ distribution unit 14. Orthogonal-polar coordinate converter 16-1 for converting from the coordinate system to polar coordinate system, and orthogonal-polar coordinate converter 16 for amplitude information.
An amplitude / phase conversion unit 16-2 that converts the output (amplitude r) of −1 into a phase φ that is phase information, and a correction table that is referred to in order to correct distortion caused by non-linearity of the amplifiers 24a and 24b are stored. Correction table storage unit 16-3
And the output from the orthogonal-polar coordinate conversion unit 16-1 (phase θ)
And an output from the correction table storage unit 16-3, a first adder 16-4, an output from the amplitude / phase conversion unit 16-2 (phase φ), and an output from the correction table storage unit 16-3. Second adder 16-5 for adding the
-4, the output (phase θ) and the output (phase φ) from the second adder 16-5 are input to convert the amplitude variation into a phase, and two divided signals S1 having a predetermined constant amplitude value, And a signal divider 16-6 that outputs S2.

Further, the phase control unit 18 includes an IQ distribution unit 14
A first buffer 18-1 for temporarily storing the input signal distributed by IQ, a second buffer 18-2 for temporarily storing the output signal output from the analog / digital (A / D) converter 30, and a first buffer The DSP (digital signal) that compares the input signal stored in 18-1 with the output signal stored in the second buffer 18-2, creates a correction table from the error signal, and outputs the correction table to the correction table storage unit 16-2. Processor) section 18-3.

With the above configuration, the operation of an example of the embodiment of the power amplifier according to the present invention will be described with reference to the phase control vector diagram for explaining the operation of the power amplifier according to the present invention shown in FIG.

The input signal is frequency-converted into an IF signal in the RF down converter 10, further A / D converted by the A / D converter 12, and then the IQ distribution unit 14 is supplied.
Is IQ distributed at. Then, the input signal IQ-distributed by the IQ distributor 14 is sent to the signal divider 16 and the phase controller 18.

Here, in the signal division section 16, IQ
The distributed input signal is divided into two divided signals S1 and S2 whose constant amplitude is controlled. At this time, by referring to the correction table storage unit 16-3 that stores the correction table value output from the DSP unit 18-3 by the process described below, I
The first addition is made between the output (phase θ) of the orthogonal-polar coordinate conversion unit 16-1 for converting the Q-divided input signal from the orthogonal coordinate system to the polar coordinate system and the correction table value stored in the correction table storage unit 16-3. An amplitude / phase conversion unit 16- that converts the output (amplitude r) of the orthogonal-polar coordinate conversion unit 16-1 into phase information while the phase is controlled by the adder 16-4.
2 output (phase φ) and correction table storage unit 16-3
The second adder 16-5 adds the correction table values stored in 1 to control the phase, thereby controlling the phase of the divided signals S1 and S2.

Further, the divided signals S1 and S2 whose phases are controlled as described above are D / A converted into analog signals by the D / A converter 20 and further frequency-converted by the RF up-converters 22a and 22b, and thereafter, The signals are amplified by the amplifiers 24a and 24b and then combined by the signal combiner 26 to form an output signal.

Here, a part of the output signal is the signal synthesizing unit 2
From the coupler of 6 through the RF down converter 28,
After being A / D converted by the A / D converter 30, it is returned to the phase controller 18.

The DSP section 18-3 of the phase control section 18 is
The output signal returned from the A / D converter 30 is compared with the input signal IQ-distributed by the IQ distributor 14, a correction table value relating to the phase is created from the error signal based on the comparison result, and the correction table value is set to a predetermined value. It is transferred to the correction table storage unit 16-3 for each cycle. At this time,
The first input signal that is IQ-distributed by the IQ distributor 14
The output signal output from the A / D converter 30 is temporarily stored in the buffer 18-1 and the second buffer 18 outputs the output signal.
-2 is temporarily stored, and the timing of the comparison process in the DSP unit 18-3 is synchronized.

Therefore, in the power amplifier according to the present invention, the amplitude distortion caused by the non-linearity of the amplifier sections 24a, 24b and the like causes the divided signal S to be generated as described above.
It can be corrected by controlling the phases of 1 and S2, and the generated distortion can be effectively removed.

FIG. 4 is a phase control vector diagram showing the control of the phases of the above-mentioned divided signals S1 and S2.
In the phase control vector diagram of FIG. 4, the input signal is S
_If the input signal is _IN and the output signal is S _OUT , the input signal S
_IN is divided into a divided signal S1 and a divided signal S2,
The divided signals S1 and S2 are output to the amplifier units 24a, 2a.
An amplitude error is received by the nonlinear distortion of 4b.

Therefore, the output signal S _OUT obtained by synthesizing the divided signal S1 and the divided signal S2 becomes different from the input signal S _IN when receiving such an amplitude error.

However, in the power amplifier according to the present invention, the phases of the divided signals S1 and S2 are controlled by the phase controller 18 and the signal divider 16 as described above, and the phases of the divided signals S1 and S2 are changed from φ. By adjusting to φ ′, the amplitude error due to the non-linear distortion of the amplifier units 24a and 24b can be corrected and the generated distortion can be removed.

Next, another example of the embodiment of the power amplifier according to the present invention (hereinafter referred to as "second embodiment" as appropriate) will be described with reference to FIG.

FIG. 5 shows a power amplifier according to the second embodiment, which corresponds to FIG. 3 and which corresponds to FIG.
8 is a detailed configuration explanatory diagram with FIG.

The power amplifier according to the second embodiment is the power amplifier according to the present invention described above with reference to FIGS. 2 to 3, except for the internal configurations of the signal division unit 16 and the phase control unit 1. Since the amplifier has the same or corresponding configuration, the description of the same or corresponding configuration will be omitted by referring to the above description and FIGS. 2 to 3. Regarding the reference numerals used in FIG. 5, the same reference numerals as those used in FIGS. 2 to 3 are used for the same or corresponding configurations.

In the power amplifier according to the second embodiment, in the signal dividing unit 16, the envelope level detecting unit 16
-7 and the amplitude control unit 16-8,
It is different from the power amplifier shown in FIGS.

That is, in the power amplifier according to the second embodiment, the envelope level detecting section 16- receives the input signal (amplitude r) converted from the rectangular coordinate system to the polar coordinate system by the orthogonal-polar coordinate converting section 16. 7 and divided signals S1 and S generated by dividing the input signal into two by converting the amplitude fluctuation of the input signal into phase information by the signal divider 16-6.
2 as well as the detection signal from the envelope level detection unit 16-7 and the divided signal S according to the detection signal.
1, and an amplitude control unit 16-8 that controls the amplitude of S2. The divided signals S1 and S2 whose amplitude is controlled by the amplitude controller 16-8 are input to the D / A converter 20 and D / A converted.

In the above-mentioned configuration, referring to the amplitude control conceptual diagram for explaining the operation of the power amplifier according to the second embodiment shown in FIG. 6 and the flowchart for the amplitude control process shown in FIG. The operation of the power amplifier according to the embodiment will be described.

Also in the power amplifier according to the second embodiment, a part of the output signal from the coupler of the signal synthesizing section 26 is supplied to the RF down converter 28 and A / D.
After returning to the phase control unit 18 via the converter 30, the DSP unit 18-3 of the phase control unit 18 creates a correction table value and transfers it to the correction table storage unit 16-3, and refers to the correction table storage unit 16-3. The point of controlling the phases of the divided signals S1 and S2 is the same as that of the power amplifier shown in FIGS. 2 to 3, and therefore description of such phase control is omitted.

However, in the power amplifier according to the second embodiment, the DSP section 18-3 also creates a correction table value relating to the amplitude, and the correction table storage section 16-3.
Is to be transferred to. The output (amplitude r) of the orthogonal-polar coordinate conversion unit 16-1 is also input to the correction table storage unit 16-3, is corrected by the correction table value related to the amplitude, and is converted into phase information, and the phase information is added by the first addition. Vessel 16-
4 and the second adder 16-5 to output the divided signal S
It is used to control the phase of 1 and S2.

In the signal divider 16 of the power amplifier according to the second embodiment, the output (amplitude r) of the orthogonal-polar coordinate converter 16-1 for converting the IQ-distributed input signal from the rectangular coordinate system to the polar coordinate system. ) Is the envelope level detection unit 1
Input to 6-7. In the envelope level detection unit 16-7, the amplitude control process shown in the flowchart of FIG. 7 is executed, the envelope level of the detected input signal and the preset threshold value are sequentially compared, and Based on the comparison result, the amplitude controller 16-8, which controls the amplitude of the divided signals S1 and S2, is processed.

That is, the orthogonal-polar coordinate converter 1 which is an input signal.
The level of the envelope (input envelope) of the output (amplitude r) of 6-1 is detected (step S702), and whether the level of the input envelope has changed to exceed the threshold value, that is, of the input envelope It is judged whether or not the level has changed so as to cut the threshold from the lower side to the upper side (step S704), and the level of the input envelope has changed so as to exceed the threshold, that is, the level of the input envelope has a threshold. When it is determined that the value has changed from the bottom to the top, the output amplitude value, which is the amplitude value given to the divided signal in the amplitude control unit 22 that controls the amplitude of the divided signals S1 and S2, is set to a large level. The value is set (step S706).

On the other hand, in the processing of step S704,
If it is not determined that the level of the envelope of the input signal has exceeded the threshold value, then the level of the envelope of the input signal has changed without exceeding the threshold value, that is, the input It is determined whether the level of the envelope of the signal has changed so as to cut the threshold value from the upper side to the lower side (step S70).
8).

Here, in the processing of step S708, the level of the input envelope is changed so as not to exceed the threshold, that is, the level of the input envelope is changed so as to cut the threshold from the upper side to the lower side. If it is determined that the output amplitude value, which is the amplitude value given to the divided signal in the amplitude control unit 16-8 that controls the amplitude of the divided signals S1 and S2, is set to a small level value (step S710).

On the other hand, in the processing of step S708,
If it is not determined that the level of the input envelope has changed so as not to exceed the threshold value, that is, if the level of the input envelope does not change to fall below the threshold value, in other words, When the level of the input envelope does not change so as to cross the threshold value, the output amplitude that is the amplitude value given to the divided signal in the amplitude control unit 16-8 that controls the amplitude of the divided signals S1 and S2. Does not change the value level.

Here, referring to the amplitude control conceptual diagram shown in FIG. 6, at the point A, the level of the input envelope changes so as to exceed the threshold, that is, the level of the input envelope changes to the threshold. Is determined to be changed from the bottom to the top, and the amplitude control unit 1 that controls the amplitude of the divided signals S1 and S2.
In 6-8, the output amplitude value, which is the amplitude value given to the divided signals S1 and S2, is changed from the small level value to the large level value (step 704 → step S706).

On the other hand, at the point B shown in FIG. 36, the level of the input envelope has changed so as not to exceed the threshold value,
That is, it is determined that the level of the input envelope has changed so as to cut the threshold value from the upper side to the lower side, and the amplitude control unit 16-8 that controls the amplitude of the divided signals S1 and S2 divides the divided signal S1 and
The output amplitude value, which is the amplitude value given to S2, is changed from a large level value to a small level value (step 704 → step S708 → step S710).

Further, at the point C shown in FIG. 6, the level of the input envelope changes so as to exceed the threshold value.
That is, it is determined that the level of the input envelope has changed so that the threshold value is cut from the lower side to the upper side, and the amplitude control unit 16-8 that controls the amplitude of the divided signals S1 and S2 outputs the divided signal S1 and
The output amplitude value, which is the amplitude value given to S2, is changed from a small level value to a large level value (step S704 → step S706).

Then, the divided signals S1 and S2 whose amplitude fluctuations are converted into phases and divided into constant amplitudes have an amplitude control section 16-8 whose output amplitude value level is controlled by the envelope level detection section 16-7. The amplitude value is controlled at.
That is, when the wet y envelope does not exceed the threshold value, the output amplitude values of the divided signals S1 and S2 are controlled to a small level, and when the wet y envelope exceeds the threshold value, the divided signals S1 and S2 are controlled.
The output amplitude value of is controlled to a large level.

Therefore, when the input envelope level cuts the threshold value from the bottom to the top (point A in FIG. 6 and point C in FIG. 6), the unit circle of the signal vector becomes the output amplitude value of the small level. The phase angle of the two vectors will widen as we move from the corresponding small diameter circle to the large diameter circle corresponding to the large level output amplitude value (see FIG. 6). On the contrary, when the input envelope level cuts the threshold value from the upper side to the lower side (point B in FIG. 6), the unit circle of the signal vector is from the large diameter circle corresponding to the large level output amplitude value to the small level. The phase angle is narrowed by shifting to a small-diameter circle corresponding to the output amplitude value of (see FIG. 6).

As described above, according to the power amplifier of the second embodiment, when the envelope does not exceed the threshold value, the amplitude of the divided signal becomes small, and the phase of the divided signal divided into two is increased. Since the angle does not spread, it becomes possible to suppress the reactive power when the amplitude is small.

That is, according to the power amplifier of the second embodiment, efficient power amplification can be realized by converting the fluctuation of the envelope level of the input signal as the phase information of the two constant amplitude signals. In addition to that, the level of fluctuation of the envelope of the input signal is detected, and the level of the divided signal input to the amplifier units 24a and 24b is changed according to the level of fluctuation of the envelope of the input signal. ,
It is possible to reduce power loss when a small signal is input to the amplifier units 24a and 24b.

In the above-described embodiment, one threshold value is set to divide the level of fluctuation of the envelope of the input signal into two levels, and the amplitude control section 1 is correspondingly divided.
The output amplitude value of the divided signal in 6-8 and the size of the unit circle of the signal vector are set to have two levels, but it is not limited to this, and the threshold value is set to 2 as a matter of course. One or more of them are set so that the level of fluctuation of the envelope of the input signal is divided into three or more stages, and accordingly the output amplitude value of the divided signal in the amplitude control unit 16-8 and the unit circle of the signal vector. May be set to have multiple levels of three or more levels.

For example, in FIG. 8, thresholds of three different values of threshold level 1, threshold level 2 and threshold level 3 are set, and the level of variation of the envelope curve is set to 4.
The amplitude control unit 16-
8 shows an example in which the output amplitude value of the divided signal in 8 and the size of the unit circle of the signal vector have four levels. By doing so, more precise control can be performed as compared with the case where the level of fluctuation of the envelope is divided into two levels, and the power loss can be further suppressed.

Regarding the timing of switching the output amplitude value of the divided signal and the size of the unit circle of the signal vector in the amplitude control section 16-8, the instantaneous value of the amplitude of the envelope of the input signal is compared with the threshold value. The switching may be made according to the result.

Further, the number of thresholds and the level of thresholds described above detect the peak power to average power ratio of the input signal, and the optimum number of thresholds and thresholds of the thresholds are detected according to the detection result. The level may be made variable so as to control the output amplitude value of the divided signal and the multi-step level relating to the size of the unit circle of the signal vector.

Furthermore, the number of thresholds and the level of thresholds described above are detected by the amplitude probability density distribution function of the input signal, and the optimum number of thresholds and thresholds are determined according to the detection result. The level may be made variable so as to control the output amplitude value of the divided signal and the multi-step level relating to the size of the unit circle of the signal vector.

As the input address of the above correction table, the IQ signal may be used, or the signal of the amplitude r and the phase θ may be used.

[0064]

Since the present invention is configured as described above, a linear amplification is performed in which an input signal is converted into two constant amplitude signals in which amplitude fluctuation is converted into phase information by using a non-linear element and then amplified. When the power is amplified by the method, it is possible to effectively remove the distortion generated in the non-linear element such as the amplitude amplifier.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a basic principle of a LINC method.

FIG. 2 is a block configuration diagram showing an example of an embodiment of a power amplifier according to the present invention.

FIG. 3 is a block configuration diagram showing a detailed configuration of a signal division unit and a phase control unit.

FIG. 4 is a phase control vector diagram for explaining the operation of the power amplifier according to the present invention.

FIG. 5 is a detailed configuration explanatory diagram of a signal division unit and a phase control unit corresponding to FIG. 3 showing a power amplifier according to a second embodiment of the present invention.

FIG. 6 is an amplitude control conceptual diagram for explaining the operation of the power amplifier according to the second embodiment of the present invention.

FIG. 7 is a flowchart relating to amplitude control processing of divided signals in an example of an embodiment of the power amplifier according to the second embodiment of the present invention.

FIG. 8 is an amplitude control conceptual diagram corresponding to FIG. 6 showing another embodiment of the power amplifier according to the second embodiment of the present invention.

[Explanation of symbols]

10 RF down converter 12 Analog / digital (A / D) converter 14 IQ distribution unit 16 Signal division unit 16-1 Orthogonal-polar coordinate conversion unit 16-2 Amplitude / phase conversion unit 16-3 Correction table storage unit 16-4 First addition 16-5 First adder 16-6 Signal divider 16-7 Envelope level detector 16-8 Amplitude controller 18 Phase controller 18-1 First buffer 18-2 Second buffer 18-3 DSP (Digital Signal processor section 20 Digital / analog (D / A) converters 22a, 22b RF up converters 24a, 24b Amplifier (Amp) section 26 Signal combining section 28 RF down converter 30 Analog / digital (A / D) converter 100 Signal dividing section (Component separator:
COMPONENTS SEPARATOR) 102a, 102b Amplifier section 104 Signal combining section

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Naoaki Segawa             2-1-1 Shibasaki, Chofu-shi, Tokyo Osamu Shimada             Chemical Industry Co., Ltd. (72) Inventor Kenji Muramoto             2-1-1 Shibasaki, Chofu-shi, Tokyo Osamu Shimada             Chemical Industry Co., Ltd. (72) Inventor Masatoshi Nakayama             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 5J090 AA01 AA41 CA21 FA19 KA00                       KA03 KA26 KA34 MA20 SA13                       TA01 TA06 TA07                 5J500 AA01 AA41 AC21 AF19 AK00                       AK03 AK26 AK34 AM20 AS13                       AT01 AT06 AT07

Claims (4)

[Claims] 1. A non-linear element is used to divide an input signal into two constant-amplitude divided signals obtained by converting amplitude fluctuations of the input signal into phase information, and the two divided signals are amplified and then combined to produce an output signal. In a power amplification method using a linear amplification method for outputting as a power amplification method, the phase of two divided signals is controlled according to the comparison result of the input signal and the output signal to correct the distortion of the amplitude of the output signal. Method. 2. An output signal obtained by dividing an input signal into two constant-amplitude divided signals obtained by converting amplitude fluctuations of the input signal into phase information using a non-linear element, amplifying the two divided signals, and then combining the amplified divided signals. In the power amplification method by the linear amplification method for outputting as, the first processing for controlling the phase of the two divided signals to correct the amplitude distortion of the output signal according to the comparison result of the input signal and the output signal, A second process of controlling the amplitude values of the two divided signals according to the amplitude of the input signal. 3. An output signal obtained by dividing an input signal into two constant amplitude divided signals obtained by converting amplitude fluctuations of the input signal into phase information using a non-linear element, amplifying the two divided signals, and then combining them. In the power amplification method by the linear amplification method for outputting as, the first processing for controlling the phase of the two divided signals to correct the amplitude distortion of the output signal according to the comparison result of the input signal and the output signal, , A process of controlling the amplitude values of the two divided signals in multiple stages according to the amplitude of the envelope of the input signal. 4. An output signal obtained by dividing an input signal into two constant-amplitude divided signals obtained by converting amplitude fluctuations of the input signal into phase information using a non-linear element, amplifying the two divided signals, and then combining the amplified divided signals. In a power amplifier of a linear amplification system that outputs as, a comparison unit that compares an input signal and an output signal, a phase control unit that controls the phases of two divided signals according to the comparison result of the comparison unit, and the input signal. A power amplifier including: a detection unit that detects the amplitude of the envelope curve; and an amplitude control unit that controls the amplitude values of the two divided signals in multiple stages according to the detection result of the detection unit.