JPH05175771A - Linear amplifier - Google Patents

Abstract

(57) [Abstract] [Purpose] With respect to a linear power amplifier, an object thereof is to prevent a decrease in efficiency and deterioration of linearity due to a change in output power based on an amplifier or a transmission system, and a change in temperature and frequency. [Structure] An amplifier 2 amplifies a modulated wave, a detector 4 detects its output, a comparator 5 obtains an envelope error from an envelope of a detection output and a reference signal, and an adder 7 obtains an envelope error and an envelope reference signal. In the linear amplifier that supplies the power to the amplifier 2 as a power source by calculating the sum of the above, a level error between the output level of the detector 4 and the output power reference signal is obtained by the level fluctuation detector 6, and the modulated wave input of the amplifier 2 is amplified. The variable gain amplifier 9, the variable gain amplifier 10 for amplifying the envelope reference signal input of the comparator 5, the variable gain amplifier 11 for amplifying the detection output envelope input of the comparator 5, or any combination thereof is gain-controlled by the level error signal. .. Alternatively, they are configured by gain control according to temperature and frequency information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear power amplifier, and more particularly to a high efficiency linear amplifier suitable for a linear modulation system.

In recent years, a linear modulation system having signal information in an amplitude component has been adopted due to a demand for digitization of communication system and improvement of frequency utilization efficiency. In the linear modulation method, if the linearity is lost, a correct modulated wave cannot be obtained.

Therefore, there is a demand for a linear amplifier which performs highly efficient linear power amplification.

[0004]

2. Description of the Related Art Among the conventionally used linear power amplifiers, in a drain control amplifier having a relatively small circuit scale and therefore being practical in terms of cost, a field effect transistor ( FET)
Is used to control the drain voltage of the. In this drain voltage control method, the envelope error voltage obtained by comparing the ideal envelope for the input and the envelope of the output is superimposed on the ideal envelope signal and is supplied as the drain power source of the FET, thereby consuming the power. It reduces power and performs linear power amplification.

[0005]

In the drain voltage control method, the error voltage between the ideal envelope and the output envelope is superimposed on the ideal envelope signal and input to the drain of the FET. On the other hand, FET
The output power changes due to gain fluctuations caused by the frequency characteristics and temperature changes of the amplifier or the frequency characteristics and temperature changes of the circuit of the transmission system, but the operating point of the drain voltage fluctuates up and down.

When the operating point of the drain voltage becomes high, FE
The efficiency of the T amplifier is reduced. Also, when the operating point of the drain voltage becomes low, the linearity cannot be maintained,
There is a problem that the phase distortion that cannot be removed by the drain voltage control method increases and the linearity deteriorates, so that the leakage power to the outside of the band increases.

The present invention is intended to solve the problems of the prior art, and even if the output power changes due to the gain change in the amplifier or the circuit of the transmission system, the efficiency is lowered, or It is an object of the present invention to provide a linear amplifier that does not increase leakage power out of band.

[0008]

SUMMARY OF THE INVENTION The present invention detects an envelope error by comparing an amplifier for amplifying a modulated wave, a detector for detecting the output of the amplifier, an envelope of the output of the detector and an envelope reference signal. The output level of the detector and the output power of the detector in a linear amplifier that has a comparator for calculating the sum of the envelope error signal and the envelope reference signal and supplies the output of the adder as a power source to the amplifier. A level fluctuation detector for comparing with a reference signal to detect a level error, a variable gain amplifier for amplifying a modulated wave and inputting it to an amplifier, or a variable gain amplifier for amplifying an envelope reference signal and inputting it to a comparator, or A variable gain amplifier for amplifying the envelope of the output of the detector and inputting it to the comparator, or an arbitrary combination of these variable gain amplifiers is provided. Depending on the level error signal is characterized in that so as to control the gain of the variable gain amplifier.

The present invention further includes an amplifier for amplifying the modulated wave, a detector for detecting the output of the amplifier, a comparator for detecting the envelope error by comparing the envelope of the output of the detector with the envelope reference signal, In a linear amplifier having an adder for obtaining the sum of the envelope error signal and the envelope reference signal, and supplying the output of the adder to the amplifier as a power supply, a temperature sensor for detecting the temperature and the detected temperature are A temperature / gain conversion circuit that converts to gain information, a variable gain amplifier that amplifies the modulated wave and inputs it to the amplifier, or a variable gain amplifier that amplifies the envelope reference signal and inputs it to the comparator, or the output of the detector. A variable gain amplifier for amplifying the envelope and inputting it to the comparator, or an arbitrary combination of these variable gain amplifiers, is provided, and In response to the output signal of the emission amount conversion circuit is characterized in that so as to control the gain of the variable gain amplifier.

The present invention further includes an amplifier for amplifying the modulated wave, a detector for detecting the output of the amplifier, and a comparator for detecting the envelope error by comparing the envelope of the output of the detector with the envelope reference signal. In a linear amplifier having an adder for obtaining the sum of an envelope error signal and an envelope reference signal, and supplying the output of the adder to the amplifier as a power supply, frequency / gain amount conversion for converting frequency information into gain information A circuit and a variable gain amplifier for amplifying a modulated wave and inputting it to an amplifier, or a variable gain amplifier for amplifying an envelope reference signal and inputting it to a comparator,
Alternatively, a variable gain amplifier that amplifies the envelope of the output of the detector and inputs it to the comparator, or an arbitrary combination of these variable gain amplifiers, is provided, and each of these variable gains is output according to the output signal of the frequency / gain amount conversion circuit. It is characterized in that the gain of the amplifier is controlled.

The present invention further comprises an amplifier for amplifying the modulated wave, a detector for detecting the output of the amplifier, and a comparator for detecting the envelope error by comparing the envelope of the detector output with the envelope reference signal. In a linear amplifier having an adder for obtaining the sum of the envelope error signal and the envelope reference signal, and supplying the output of the adder to the amplifier as a power supply, a temperature sensor for detecting the temperature and the detected temperature are A temperature / gain amount conversion circuit that converts gain information, a frequency / gain amount conversion circuit that converts frequency information to gain information, a variable gain amplifier that amplifies the modulated wave and inputs it to the amplifier, or an envelope reference signal is amplified. Variable gain amplifier for input to the comparator, or a variable gain amplifier for amplifying the envelope of the output of the detector and inputting to the comparator, or An arbitrary combination of these variable gain amplifiers is provided, and the output signal of the temperature / gain amount conversion circuit and the output signal of the frequency / gain amount conversion circuit are combined at an arbitrary ratio to control the gain of each variable gain amplifier. It is characterized by doing so.

The present invention further includes a modulator for modulating a baseband signal and a variable gain amplifier for amplifying the baseband signal and inputting it to the modulator in each of the linear amplifiers of the respective inventions. The gain of the variable gain amplifier is controlled according to the output signal of the gain amount conversion circuit, the output signal of the frequency / gain amount conversion circuit, or a combination thereof.

[0013]

1 shows the principle configuration of the present invention, in which 1 is a modulator for modulating a baseband signal, 2 is an amplifier for amplifying a modulated wave, and 3 is an output of the amplifier 2. Distributor 4, detector for detecting transmitted wave, 5 comparator for detecting envelope error by comparing envelope of transmitted wave with envelope reference signal, 6 for comparing level of transmitted wave with output power reference signal And a level fluctuation detector for detecting a level error, 7 is an adder for adding the envelope error signal and the envelope reference signal, 8 is a variable gain amplifier for amplifying the baseband signal and inputting it to the modulator 1, and 9 is A variable gain amplifier that amplifies the modulated wave and inputs it to the amplifier 2.
Reference numeral 0 is a variable gain amplifier for amplifying the envelope reference signal and inputting it to the comparator 5, and 11 is a variable gain amplifier for amplifying the envelope of the transmission wave and inputting it to the comparator 5.

The modulator 1 modulates a local signal with a baseband signal to generate, for example, a π / 4 shift QPSK modulated wave. The amplifier 2 linearly amplifies the modulated wave using the voltage supplied from the adder 7 as a power source, and amplifies it to a required transmission power. The distributor 3 distributes the output power of the amplifier 2 to output a transmission wave, and inputs a part of the output to the detector 4. The detector 4 detects the input from the distributor 3. The comparator 5 compares the envelope of the transmission wave detected by the detector 4 with the envelope reference signal to generate an envelope error signal. The adder 7 takes the sum of the envelope error signal and the envelope reference signal and supplies the sum to the amplifier 2 as a drain power supply voltage, for example.

As described above, in the linear amplifier shown in FIG. 1, when the modulated wave is amplified by the amplifier 2, the error between the envelope of the transmission wave output and the envelope reference signal is superimposed on the envelope reference signal, and the amplifier 2 Is supplied as a power supply voltage to the amplifier 2, the amplifier 2 can be operated by a power supply voltage whose magnitude changes according to the magnitude (envelope) of the input modulated wave, and thus the efficiency of the amplifier 2 can be improved and The modulated wave can be linearly amplified up to the required transmission power.

At this time, according to the level error signal obtained by comparing the level of the transmission wave with the output power reference signal in the level fluctuation detector 6, the variable gain for amplifying the baseband signal input to the modulator 1 Since the gain of the amplifier 8 is controlled to change the magnitude of the baseband signal input,
It becomes possible to compensate the change in the transmission wave level due to the gain variation of the amplifier 2 or the circuit of the transmission system, and to make the efficiency and linearity of the amplifier 2 constant.

In this case, instead of controlling the gain of the variable gain amplifier 8 by the level error signal, the variable gain amplifier 9 for amplifying the modulated wave input to the amplifier 2 or the envelope reference signal input to the comparator 5 is amplified. The same effect can be obtained by controlling the gain of either the variable gain amplifier 10 that controls the gain or the variable gain amplifier 11 that amplifies the detection output envelope input to the comparator 5 according to the level error signal. Or variable gain amplifiers 8, 9, 10, 11
May be combined arbitrarily to control the gain by the level error signal.

FIG. 2 shows another principle structure of the present invention, in which the same components as those in FIG. 1 are designated by the same reference numerals, and 12 is a temperature sensor, which detects a temperature and outputs a voltage signal. Converted to and output. A temperature / gain amount conversion circuit 13 converts the temperature output voltage of the temperature detector 12 into a gain control voltage for the variable gain amplifiers 8-11. Also,
A frequency / gain amount conversion circuit 14 converts frequency information into gain control voltages for the variable gain amplifiers 8 to 11.

The operation of the circuit composed of the modulator 1, the amplifier 2, the distributor 3, the detector 4, the comparator 5, and the adder 7 is the same as that in the case of FIG. The temperature sensor 12 detects the temperature and generates a temperature output voltage. The temperature / gain amount conversion circuit 13 converts the temperature output voltage of the temperature sensor 12 into a gain control voltage for the variable gain amplifiers 8-11. This gain control voltage changes the input voltage of the amplifier 2 or the envelope error so that the efficiency and linearity of the amplifier 2 become constant even if the temperature changes by changing the gains of the variable gain amplifiers 8 to 11. It changes the size.
The variable gain amplifiers 8 to 11 compensate the change in the transmission wave level due to the gain variation in the amplifier 2 or the circuit of the transmission system by changing the gain according to the gain control voltage. Alternatively, it is possible to eliminate the effect of temperature change in the circuit of the transmission system and make the efficiency and linearity of the amplifier 2 constant.

The frequency / gain amount conversion circuit 14 is
The frequency information is converted into a gain control voltage for the variable gain amplifiers 8-11. This gain control voltage changes the gains of the variable gain amplifiers 8 to 11 so that the efficiency and linearity of the amplifier 2 become constant even if the frequency changes.
The variable gain amplifiers 8 to 11 compensate for the change in the transmission wave level based on the gain change in the amplifier 2 or the circuit of the transmission system by changing the gain according to the gain control voltage. Alternatively, it is possible to eliminate the influence of frequency change in the circuit of the transmission system and make the efficiency and linearity of the amplifier 2 constant.

In the principle configuration of FIG. 1, when the gain of the amplifier 2 or the circuit of the transmission system fluctuates, the level of the transmission wave obtained by the detector 4 and the output power reference signal are compared with the level fluctuation detector 6 A level error signal indicating the amount of fluctuation is generated by comparing with.

When the gain of the variable gain amplifier 8 or 9 is controlled by the level error signal, the gain of the variable gain amplifier 8 or 9 is decreased when the gain of the amplifier 2 or the like is increased, and conversely, the gain of the amplifier 2 is decreased. When the gains such as 1 are decreased, the power of the transmission wave at the output of the distributor 3 can be made substantially constant by increasing the gain of the variable gain amplifier 8 or 9. As a result, the detection output voltage of the detector 4 becomes the optimum value, and the supply voltage to the amplifier 2 becomes substantially equal to the optimum voltage before the gain change.

When the gain of the variable gain amplifier 10 is controlled by the level error signal, when the gain of the amplifier 2 or the like increases, the gain of the variable gain amplifier 10 is increased,
When the gain of the amplifier 2 or the like decreases, the variable gain amplifier 1
Reduce the gain of 0. Variable gain amplifier 10 in this case
The gain control amount is adjusted to match the increase in the output of the detector 4 due to the increase in the gain of the amplifier 2 or the like. As a result, the average value of the envelope error signal at the output of the comparator 5 does not fluctuate and operates in the same manner as the loop gain increases. Therefore, the supply voltage to the amplifier 2 becomes the optimum voltage before the gain change. Are almost equal.

When the gain of the variable gain amplifier 11 is controlled by the level error signal, the gain of the variable gain amplifier 11 is decreased when the gain of the amplifier 2 or the like is increased,
When the gain of the amplifier 2 or the like decreases, the variable gain amplifier 1
Increase the gain of 0. As a result, the input to the comparator 5 becomes constant regardless of the change in the gain of the amplifier 2 or the like, so that the supply voltage to the amplifier 2 becomes substantially equal to the optimum voltage before the gain change.

In the principle configuration of FIG. 2, the signal corresponding to the level error signal from the level fluctuation detector 6 in the principle configuration of FIG.
The amount generated from the gain amount conversion circuit 13 and corresponding to the change in the frequency characteristic is calculated by the frequency / gain amount conversion circuit 14
To occur from.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 shows the configuration of an embodiment of the present invention. Reference numeral 22 is a FET amplifier, which corresponds to the amplifier 2 in FIG. Reference numeral 23 denotes a distributor, which corresponds to the distributor 3 in FIG. Reference numeral 24 is a diode detector, which corresponds to the detector 4 in FIG.
Reference numeral 25 denotes a comparator, which corresponds to the comparator 5 in FIG. Reference numeral 26 is a level fluctuation detector, which corresponds to the level fluctuation detector 6 in FIG. 27 is an adder,
It corresponds to the adder 7 in FIG. A variable gain amplifier 29 corresponds to the variable gain amplifier 9 in FIG. In the level fluctuation detector 26, 31 is a low-pass filter and 32 is a comparator. 33 is an amplifier,
Determine the loop gain of the control loop for the variable gain control amplifier 29. The FET amplifier 22 operates by being supplied with a constant voltage V _G at its gate and being supplied with the addition output of the adder 27 as its power supply at its drain.

Since the variation of the gain due to the variation of the temperature or the frequency characteristic is gentler than the variation of the envelope component of the modulated wave, the variation due to the envelope component is removed by the low pass filter 31, and only the variation of the level is extracted. The comparator 32 compares the output of the low-pass filter 31 with the output power reference signal to obtain the level change amount based on the gain change and inputs it to the variable gain amplifier 29 to control the gain thereof. , Determine the loop gain in the feedback loop in this case. By such feedback, the output power of the amplifier 22 changes following the output power reference signal, and the drain voltage of the output of the adder 27 always operates at a constant operating point.

FIG. 4 shows the configuration of another embodiment of the present invention, in which the same components as those in FIG. 3 are designated by the same reference numerals, and 30 is a variable gain amplifier, and the variable gain amplifier in FIG. It corresponds to the amplifier 10. 34 is an amplifier,
The loop gain of the control loop for the variable gain control amplifier 30 is defined.

In FIG. 4, the level error signal based on the gain change obtained by the level fluctuation detector 26 is
It is input to the variable gain amplifier 30 and its gain is controlled.
The amplifier 33 determines the loop gain in the feedback loop in this case, and the change in the gain of the variable gain amplifier 30 is matched with the gain fluctuation of the amplifier 22 and the like by the amplifier 33. By such feedback, the output power of the amplifier 22 changes following the output power reference signal, and the drain voltage of the output of the adder 27 always operates at a constant operating point.

FIG. 5 shows the configuration of still another embodiment of the present invention, in which the same components as those in FIG. 3 are designated by the same reference numerals, and 35 is a thermistor, which is the temperature sensor 12 in FIG. ， Corresponding to the temperature / gain converter 13,
The resistance value changes depending on the temperature.

In the embodiment of FIG. 5, the resistance of the thermistor 35 changes according to the temperature, and the gain is controlled by changing the control voltage applied to the variable gain amplifier 29. By such feedback, the output power of the amplifier 22 changes following the output power reference signal, and the drain voltage of the output of the adder 27 always operates at a constant operating point.

FIG. 6 shows the structure of still another embodiment of the present invention. The same parts as those in FIG. 3 are designated by the same reference numerals, and 36 is a read only memory (ROM),
37 is a digital analog (D / A) converter,
These correspond to the frequency / gain amount converter 14 in FIG. The ROM 36 describes the relationship between frequency and gain, and the variable gain amplifier 2 according to frequency information.
The digital data of the voltage given to 9 is stored. The digital / analog (D / A) converter 37 converts the output of the ROM 36 into an analog voltage.

In the embodiment shown in FIG. 6, by utilizing the fact that the output from the D / A converter 37 changes according to the frequency, the gain is changed by changing the control voltage applied to the variable gain amplifier 29. Control. By such feedback, the output power of the amplifier 22 changes following the output power reference signal, and the drain voltage of the output of the adder 27 always operates at a constant operating point.

FIG. 7 shows another example of the structure of the level fluctuation detector. 41 is a sample and hold circuit, 42 is a switch, 43 is a low pass filter, and 44 is a comparator. When the transmission wave is a burst signal, the output of the level fluctuation detector 26 shown in FIGS. 3 and 4 fluctuates, and a level error signal corresponding to a change in the gain of the amplifier 22 or the like cannot be correctly generated. The level fluctuation detector shown in FIG. 7 can generate a level error signal substantially corresponding to a change in the gain of the amplifier 22 or the like even when the transmission wave is a burst signal.

FIG. 8 is a time chart for explaining the operation of the level fluctuation detector of FIG. When the transmission wave is not output for a long time, the switch 42 in FIG. 7 is set to the state c, and the output power reference signal is input to the low-pass filter 43 to set the level error signal output of the comparator 44 to the standard state. Allows for optimal operation.

Next, when the burst transmission is started, the switch 42 is set to a state by burst on and connected to the output of the detector 24, and when the burst is turned off, the switch 42 is set in state b and the sample-and-hold circuit. Four
Connect to the output of 1. Sample and hold circuit 41
Holds the output value of the low-pass filter 43 at the time of burst-on by sampling at the point of ↑ and holding the sampled value thereafter. Therefore, the output of the comparator 44 at the time of burst-off is It is kept in the same constant condition as time. The output of the comparator 44 is supplied to the variable gain amplifier as a gain control signal.

At the time of the first burst-on, the output of the comparator 44 does not correctly correspond to the change in the gain of the amplifier 22 or the like due to the time delay depending on the time constant of the low pass filter 43. However, the output voltage of the low-pass filter 43 is the same as that of the sample-and-hold circuit 41.
And the burst-off time is sufficiently shorter than the time in which the gain of the amplifier 22 or the like changes, so that the output of the comparator 44 is equal to the gain of the amplifier 22 or the like from the second burst-on time. It will respond to changes.

FIG. 9 shows still another example of the structure of the level fluctuation detector. The same components as those in FIG. 7 are designated by the same reference numerals, and 45 is a switch.

FIG. 10 is a time chart for explaining the operation of the level fluctuation detector of FIG. Immediately before outputting the transmission wave, set the switch 45 in FIG. 9 to the state of b,
By inputting the output power reference signal to the low-pass filter 43, the sample-and-hold circuit 41 holds the output power reference signal and sets the level error signal of the comparator 44 to the standard state so as to perform the optimum operation. To do.

Next, when the burst transmission is started, the switch 45 is set to the state of "a" by burst-on and is connected to the output of the detector 24. At the same time, the sample-and-hold circuit 41 samples the output of the detector 24. At this time, the sampling is started with a delay of the time constant t of the low-pass filter 43 from the burst-on until just before the burst-off. Sampling for time T, when time T has elapsed,
Hold as indicated by the ↓ mark. Therefore, the sample-and-hold circuit 41 holds the signal in which the output voltage of the low-pass filter 43 is stable, so that the voltage indicating the correct transmission power is held.

At the time of the first burst-on, the output of the comparator 44 does not correctly correspond to the change in the gain of the amplifier 22 or the like, due to the delay in the low-pass filter 43, at a certain part of the first sampling period. However, from the next burst-on time, the output of the comparator 44 correctly corresponds to the change in the gain of the amplifier 22 and the like.

FIG. 11 shows still another example of the structure of the level fluctuation detector, in which 46 is a comparator and 4
7 is a digital filter.

The comparator 46 generates a binary output depending on whether the output voltage of the detector 24 is larger than the output power reference signal. This output is smoothed through the digital filter 47 and is supplied as a level error signal to any of the variable gain amplifiers via the electronic volume control and the digital / analog (D / A) converter, so that the amplifier 22 and the like are correctly processed. A variable gain control voltage corresponding to the change in gain can be output.

FIG. 12 shows still another example of the structure of the level fluctuation detector. The same components as those in FIG. 11 are designated by the same numerals, and 48 is an analog digital (A /
D) A converter.

The A / D converter 48 converts the output voltage of the detector 24 into a digital signal. This signal is smoothed through a digital filter 47, and then is compared with an output power reference signal in a comparator 44 to generate a level error signal, which is passed through an electronic volume and a digital analog (D / A) converter. By being supplied to any one of the variable gain amplifiers, the variable gain control voltage that correctly corresponds to the change in the gain of the amplifier 22 or the like can be output.

In each of the above configuration examples, the optimum level error signal cannot be output because the level error signal output does not reach a steady state at the start of burst transmission, at the time of the first burst input, but the bandpass filter is not output. By using a variable width filter, the time constant can be reduced, the time required to generate a steady output can be shortened, and the optimum control state can be achieved in a short time.

[0047]

As described above, according to the present invention, the linear power amplification is performed by superimposing the error between the amplifier output envelope and the envelope reference signal on the envelope reference signal and supplying it as the power source of the amplifier. In the linear amplifier, the fluctuation of the transmission power is detected and the variable gain amplifier is controlled to make the voltage supplied to the amplifier constant or the average power of the input of the error comparator constant. It is possible to prevent the efficiency of the linear amplifier from being lowered and the linearity from being deteriorated due to the fluctuation of the gain of the transmission system.

[Brief description of drawings]

FIG. 1 is a diagram showing a principle configuration of the present invention.

FIG. 2 is a diagram showing another principle configuration of the present invention.

FIG. 3 is a diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 4 is a diagram showing the configuration of another embodiment of the present invention.

FIG. 5 is a diagram showing the configuration of still another embodiment of the present invention.

FIG. 6 is a diagram showing the configuration of still another embodiment of the present invention.

FIG. 7 is a diagram showing another configuration example of the level fluctuation detector.

FIG. 8 is a time chart explaining the operation of the level fluctuation detector of FIG.

FIG. 9 is a diagram showing still another configuration example of the level fluctuation detector.

FIG. 10 is a time chart for explaining the operation of the level fluctuation detector of FIG.

FIG. 11 is a diagram showing still another configuration example of the level fluctuation detector.

FIG. 12 is a diagram showing still another configuration example of the level fluctuation detector.

[Explanation of symbols]

 1 modulator 2 amplifier 4 wave detector 5 comparator 6 level fluctuation detector 7 adder 8-11 variable gain amplifier 12 temperature sensor 13 temperature / gain amount conversion circuit 14 frequency / gain amount conversion circuit

Claims (5)

[Claims] 1. An amplifier (2) for amplifying a modulated wave, a detector (4) for detecting an output of the amplifier (2), and an envelope of an output of the detector (4) and an envelope reference signal. (5) for detecting envelope error
And an adder (7) for calculating the sum of the envelope error signal and the envelope reference signal, and the output of the adder (7) is supplied to the amplifier (2) as a power supply. A level fluctuation detector (6) for detecting a level error by comparing the output level of the detector (4) with an output power reference signal; and a variable for amplifying the modulated wave and inputting it to the amplifier (2). A gain amplifier (9) or a variable gain amplifier (10) for amplifying the envelope reference signal and inputting it to the comparator (5) or an envelope of the output of the detector (4) is amplified and the comparator (5). And a variable gain amplifier (11) to be input to or any combination of the variable gain amplifiers (9 to 11), and the gain of each variable gain amplifier is controlled according to the level error signal. Linear amplifier according to claim. 2. An amplifier (2) for amplifying a modulated wave, a detector (4) for detecting an output of the amplifier (2), and an envelope of an output of the detector (4) and an envelope reference signal. (5) for detecting envelope error
And an adder (7) for calculating the sum of the envelope error signal and the envelope reference signal, and the output of the adder (7) is supplied to the amplifier (2) as a power supply. , Temperature sensor to detect temperature (1
2), a temperature / gain amount conversion circuit (13) for converting the detected temperature into gain information, and a variable gain amplifier (9) for amplifying the modulated wave and inputting it to the amplifier (2) or the envelope. Variable gain amplifier (10) for amplifying a reference signal and inputting it to the comparator (5) or variable gain amplifier (11) for amplifying the envelope of the output of the detector (4) and inputting it to the comparator (5). ) Or any combination of the variable gain amplifiers (9 to 11), and the gain of each variable gain amplifier is controlled according to the output signal of the temperature / gain amount conversion circuit (13). A linear amplifier characterized by. 3. An amplifier (2) for amplifying a modulated wave, a detector (4) for detecting an output of the amplifier (2), and an envelope of an output of the detector (4) and an envelope reference signal. (5) for detecting envelope error
And an adder (7) for calculating the sum of the envelope error signal and the envelope reference signal, and the output of the adder (7) is supplied to the amplifier (2) as a power supply. A frequency / gain amount conversion circuit (14) for converting frequency information into gain information, and a variable gain amplifier (9) for amplifying the modulated wave and inputting it to the amplifier (2) or for amplifying the envelope reference signal. The variable gain amplifier (10) input to the comparator (5) or the variable gain amplifier (11) that amplifies the envelope of the output of the detector (4) and inputs it to the comparator (5), or each of the variable gains. An arbitrary combination of amplifiers (9 to 11) is provided, and the gain of each variable gain amplifier is controlled according to the output signal of the frequency / gain amount conversion circuit (14). Linear amplifier to. 4. An amplifier (2) for amplifying a modulated wave, a detector (4) for detecting an output of the amplifier (2), and an envelope of an output of the detector (4) and an envelope reference signal. (5) for detecting envelope error
And an adder (7) for calculating the sum of the envelope error signal and the envelope reference signal, and the output of the adder (7) is supplied to the amplifier (2) as a power supply. , Temperature sensor to detect temperature (1
2), a temperature / gain amount conversion circuit (13) for converting the detected temperature into gain information, a frequency / gain amount conversion circuit (14) for converting frequency information into gain information, and the modulator (1). ), The variable gain amplifier (9) for amplifying the output of the amplifier and inputting it to the amplifier (2), or the variable gain amplifier (10) for amplifying the envelope reference signal and inputting it to the comparator (5), or the detector ( Variable gain amplifier (11) for amplifying the envelope of the output of 4) and inputting it to the comparator (5), or each variable gain amplifier (9 to 11).
And the output signal of the temperature / gain amount conversion circuit (13) and the output signal of the frequency / gain amount conversion circuit (14) are combined at an arbitrary ratio. A linear amplifier characterized in that the linear amplifier is controlled. 5. The linear amplifier according to claim 1, 2 or 3 or 4, wherein a modulator (1) for modulating a baseband signal, and the baseband signal is amplified and input to the modulator (1). And a variable gain amplifier (8) for
The gain of the variable gain amplifier (8) is controlled according to the level error signal, the output signal of the temperature / gain amount conversion circuit (13), the output signal of the frequency / gain amount conversion circuit (14), or a combination thereof. A linear amplifier characterized in that