JP2758682B2 - Constant amplitude wave synthesis type amplifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] A constant amplitude wave synthesis type amplifier of the LINC type is intended to reduce the power consumption, reduce the circuit scale, and increase the speed of the constant amplitude wave synthesis amplifier. An auxiliary wave generation circuit composed of an analog circuit that generates an auxiliary wave for generating a constant amplitude wave by approximately combining the input signal wave with the input signal wave, and an auxiliary wave generation circuit for the auxiliary wave generation circuit A constant-amplitude-wave generating circuit composed of an analog circuit that generates two constant-amplitude waves by synthesizing the signal waves with each other; and a two-amplitude amplifier that separately amplifies two predetermined-amplitude waves output from the constant-amplitude-wave generating circuit. Two amplifiers,
A combining circuit that combines the constant-amplitude waves amplified by the two amplifiers to generate an output signal wave.

[Industrial Application Field] The present invention relates to a LINC (Linear Amplification with Nonlin
ear components) type constant amplitude wave synthesis type amplifier.

The constant-amplitude wave combining amplifier is a low-distortion, high-efficiency power amplifier applied to various communication devices such as a mobile communication wireless device, a multiplex wireless device, a satellite communication wireless device, and a broadcast device. It is required that this constant-amplitude wave synthesis type amplifier can be realized with low power consumption and a small-scale circuit configuration.

[Prior Art] Conventionally, as a power amplifier that can achieve low distortion and high efficiency, a constant amplitude wave synthesis type amplifier using a LINC method is known. The principle of this constant-amplitude wave synthesis amplifier is described by Bell Labs D.
Proposed by C.COX, IEEE, COM-22, P194
It is disclosed in 2 etc. As an application example, a method of Tomisato et al. Is disclosed in Japanese Patent Application Laid-Open No. 1-284106.

FIG. 22 shows a configuration example of a conventional constant amplitude wave synthesis type amplifier. In the figure, reference numeral 61 denotes a constant-amplitude-wave calculation circuit, which is constituted by a digital signal processing circuit, and calculates a quadrature wave Y such that a composite wave with an input signal wave has a constant amplitude. By combining the signal wave X and the orthogonal wave Y, two constant amplitude waves A and B having a constant envelope and equal amplitude are generated and output. Here, the uppercase letters X, Y, A, and B represent vector quantities including the phase.

62 and 63 are two constant amplitude waves A and B of the constant amplitude wave operation circuit 61.
Are amplified separately, and a highly efficient non-linear amplifier such as a class C amplifier is used.

A synthesis circuit 64 synthesizes the constant amplitude waves kA and kB amplified by the amplifiers 62 and 63, and outputs the amplified output wave kX as an amplified output of the input wave X.
Generate

In this conventional constant-amplitude-wave synthesizing amplifier, an input wave X is converted into two constant-amplitude waves A and B by a constant-amplitude-wave arithmetic circuit 61, and amplified by amplifiers 62 and 63, respectively. Are synthesized by the synthesis circuit 64 to obtain an output wave kX which is an amplified output of the original input wave X.

In this constant amplitude wave synthesis type amplifier, amplifiers 62 and 63
Only amplifies the constant-amplitude waves A and B of the constant envelope, it is not necessary to use a linear amplifier, and a highly efficient non-linear amplifier such as class C can be used. Since the original signal can be restored by the circuit 64, amplification with low distortion and high linearity can be performed using a nonlinear amplifier. As described above, the constant-amplitude wave synthesis type amplifier can realize a highly efficient and low distortion amplifier using a non-linear amplifier.

[Problems to be Solved by the Invention] Generally, in a conventional constant-amplitude-wave synthesizing amplifier, a constant-amplitude-wave arithmetic circuit 61 that generates two constant-amplitude waves A and B from an input wave X is used.
Are configured using a digital signal processing circuit.
However, when a digital signal processing circuit is used, there is a problem in that the power consumption in the constant-amplitude wave operation circuit increases, the high-speed signal processing cannot be followed, and the circuit scale is further increased.

For this reason, the conventional constant-amplitude wave synthesis type amplifier has a sufficiently large amplification power consumption as compared with that of the digital signal processing circuit, so that the power consumption in this digital signal processing circuit can be ignored or there is no size limitation. Its use is limited, for example, when used for a device transmitting low-speed signals.
In order to solve the above problems, it is necessary to advance the semiconductor technology such as low power consumption, high speed and ultra LSI of the semiconductor.

The present invention has been made in view of such technical problems, and an object of the present invention is to reduce the power consumption, reduce the circuit scale, and increase the speed of a constant-amplitude wave synthesis amplifier. .

[Means for Solving the Problems] FIGS. 1 to 8 are explanatory diagrams of the principle according to the present invention.

As shown in FIG. 1, the constant-amplitude wave synthesis type amplifier according to the present invention, as shown in FIG. 1, combines an input signal wave and an auxiliary wave for generating a constant-amplitude wave from the input signal wave. An auxiliary wave generation circuit 81 composed of an analog circuit that is generated by approximately calculating, and an analog circuit that generates two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generation circuit 81 and the input signal wave. A constant amplitude wave generating circuit 82, two amplifiers 83 and 84 for separately amplifying the two constant amplitude waves output from the constant amplitude wave generating circuit 82, and a constant amplifier amplified by the two amplifiers 83 and 84, respectively. A synthesizing circuit 85 for synthesizing the amplitude wave to generate an output signal wave.

Further, as another form of the constant amplitude wave synthesizing amplifier according to the present invention, as shown in FIG. 2, an auxiliary wave for generating a constant amplitude wave by synthesizing with an input signal wave is generated from the input signal wave. An auxiliary wave generation circuit 81 composed of an analog circuit that is generated by approximately calculating, and an analog circuit that generates two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generation circuit 81 and the input signal wave. A constant amplitude wave generating circuit 82, two amplifiers 83 and 84 for separately amplifying the two constant amplitude waves output from the constant amplitude wave generating circuit 82, and a constant amplifier amplified by the two amplifiers 83 and 84, respectively. A synthesizing circuit 85 for synthesizing the amplitude wave to generate an output signal wave, and comparing the output signal wave of the synthesizing circuit 85 with the input signal wave to detect a distortion component in the output signal wave. Correction to cancel distortion of output signal wave Generated and formed by and a correction circuit 86 applied to the input signal wave.

Further, as another form of the constant amplitude wave synthesizing amplifier according to the present invention, as shown in FIG. 3, an auxiliary wave for generating a constant amplitude wave by synthesizing with an input signal wave is generated from the input signal wave. An auxiliary wave generation circuit 81 composed of an analog circuit that is generated by approximately calculating, and an analog circuit that generates two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generation circuit 81 and the input signal wave. A constant amplitude wave generating circuit 82, two amplifiers 83 and 84 for separately amplifying the two constant amplitude waves output from the constant amplitude wave generating circuit 82, and a constant amplifier amplified by the two amplifiers 83 and 84, respectively. A combining circuit 87 that combines the amplitude wave to generate an output signal wave and an output auxiliary wave, and compares the output auxiliary wave from the combining circuit 87 with the auxiliary wave of the auxiliary wave generation circuit 81 to reduce distortion components in the output auxiliary wave. Detects the output auxiliary wave distortion based on the detected output. A correction circuit 88 that generates a correction value that cancels out and adds the correction value to the auxiliary wave of the auxiliary wave generation circuit 81
And

Further, as another form of the constant amplitude wave synthesizing amplifier according to the present invention, as shown in FIG. 4, an auxiliary wave for generating a constant amplitude wave by combining with an input signal is approximated from the input signal wave. Auxiliary wave generation circuit 81 composed of an analog circuit that is generated by performing an arithmetic operation, and a constant amplitude composed of an analog circuit that generates two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generation circuit 81 and the input signal. A wave generation circuit 82, two amplifiers 83 and 84 for separately amplifying the two constant amplitude waves output from the constant amplitude wave generation circuit 82, and two amplifiers.
A combining circuit 85 that combines the constant amplitude waves amplified by 83 and 84 to generate an output signal wave, a variable gain amplifier 89 that variably adjusts the size of the auxiliary wave from the auxiliary wave generating circuit 81, and a combining circuit The output signal wave of 85 is compared with the input signal wave to detect a distortion component in the output signal wave, and the gain of the variable gain amplifier 89 is controlled based on the detected output so as to cancel the distortion of the output signal wave of the synthesis circuit 85. And a control circuit 90.

Further, as another form of the constant amplitude wave synthesizing amplifier according to the present invention, as shown in FIG. 5, an auxiliary wave for generating a constant amplitude wave by combining with an input signal wave is generated from the input signal wave. An auxiliary wave generation circuit 81 composed of an analog circuit that is generated by approximately calculating, and an analog circuit that generates two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generation circuit 81 and the input signal wave. A constant amplitude wave generating circuit 82, two amplifiers 83 and 84 for separately amplifying the two constant amplitude waves output from the constant amplitude wave generating circuit 82, and a constant amplifier amplified by the two amplifiers 83 and 84, respectively. A synthesizing circuit 85 that synthesizes an amplitude wave to generate an output signal wave, and a variable gain amplifier 89 that variably adjusts the size of the auxiliary wave from the auxiliary wave generating circuit 81
And a variable gain amplifier that compares the constant amplitude wave of the constant amplitude wave generation circuit 82 with a predetermined reference value so that the constant amplitude wave has a constant amplitude.
And a control circuit 91 for controlling the gain of 89.

Further, as another form of the constant-amplitude-wave combining amplifier according to the present invention, as shown in FIG. 6, an auxiliary wave for generating a constant-amplitude wave by combining with an input signal wave is generated from the input signal wave. An auxiliary wave generation circuit 81 composed of an analog circuit that is generated by approximately calculating, and an analog circuit that generates two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generation circuit 81 and the input signal wave. A constant amplitude wave generating circuit 82, two amplifiers 83 and 84 for separately amplifying the two constant amplitude waves output from the constant amplitude wave generating circuit 82, and constant amplitudes respectively amplified by the two amplifiers 83 and 84. A combining circuit 87 that combines the waves to generate an output signal wave and an output auxiliary wave, a variable gain amplifier 89 that variably adjusts the size of the auxiliary wave from the auxiliary wave generation circuit 81, and an output auxiliary wave of the combining circuit 85. Auxiliary wave generation circuit
A control circuit 92 for controlling the gain of the variable gain amplifier 89 so as to detect a distortion component in the output auxiliary wave by comparing with the auxiliary wave of 81 and cancel the distortion of the output auxiliary wave of the combining circuit 87 based on the detected output. It is provided.

As another embodiment, as shown in FIG. 7, the constant-amplitude wave combining amplifier according to the present invention has a constant amplitude of two amplifiers 83 and 84 in each of the embodiments shown in FIGS. Two second amplifiers 93 and 94 for amplifying the respective waves, and a second combining unit for combining the constant amplitude waves respectively amplified by the two second amplifiers 93 and 94 to generate an amplified output signal wave. circuit
95 is further provided.

Further, as another form of the constant amplitude wave synthesis type amplifier according to the present invention, as shown in FIG. 8, in each of the above-described embodiments, the auxiliary wave generation circuit 81 sends the input signal wave to the limiter circuit 911. The difference wave between the output of the limiter circuit 911 and the input signal wave is calculated by a differentiator 912 to calculate the auxiliary wave.

[Operation] In the constant-amplitude-wave synthesizing amplifier of the embodiment of FIG. 1, when the input signal wave and the auxiliary wave orthogonal thereto are vector-synthesized in the auxiliary wave generation circuit 81, the amplitude of the synthesized wave becomes a constant amplitude. The magnitude of the auxiliary wave is approximately determined by an analog circuit. Then, based on the auxiliary wave and the input signal wave, the constant amplitude wave generation circuit 82 generates two constant amplitude waves having a constant envelope, and the two constant amplitude waves are amplified by the amplifiers 83 and 8, respectively. The signal is synthesized by the synthesizing circuit 85 to return to the original signal wave, thereby obtaining an output signal wave which is an amplified output of the input signal wave. In this case, since the amplifiers 83 and 84 amplify the constant-amplitude wave, a highly efficient nonlinear amplifier can be used.

In the constant-amplitude wave synthesizing amplifier of the embodiment shown in FIG. 2, a distortion component generated in an output signal wave is detected by a correction circuit 86 based on an approximation operation of an auxiliary wave generation circuit 81, and this distortion component is canceled. The correction value is added to the input signal wave in a direction to reduce the distortion of the output signal wave.

In the constant-amplitude wave synthesis type amplifier of the embodiment shown in FIG.
The distortion of the output auxiliary wave is reduced by adding a correction value to the auxiliary wave of the auxiliary wave generation circuit 81 in the direction in which the distortion component is detected and the distortion component is cancelled.

In the constant-amplitude wave synthesis type amplifier of the embodiment shown in FIG. 4, the control circuit controls the distortion component generated in the output signal wave based on the fact that the auxiliary wave generation circuit 81 is an approximate operation and the distortion component generated in the output signal wave.
The magnitude of the auxiliary wave of the auxiliary wave generation circuit 81 is adjusted by the variable gain amplifier 89 so as to eliminate the distortion component detected at 90, thereby reducing the distortion component.

In the constant amplitude wave synthesis type amplifier of the embodiment shown in FIG. 5, the distortion component generated in the output signal wave based on the approximation operation of the auxiliary wave generation circuit 81 is converted into the constant amplitude wave on the output side of the constant amplitude wave generation circuit 82. Is adjusted by adjusting the magnitude of the auxiliary wave of the auxiliary wave generation circuit 81 by the variable gain amplifier 89 through the control circuit 91 so that the amplitude becomes constant.

In the constant-amplitude-wave synthesis type amplifier of the embodiment shown in FIG.
The magnitude of the auxiliary wave of the auxiliary wave generation circuit 81 is reduced by adjusting the amplitude of the auxiliary wave by the variable gain amplifier 89 in comparison with 92.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. In the following description, it is assumed that components denoted by the same reference numerals represent the same circuit components throughout the drawings.

FIG. 9 shows a constant-amplitude wave combining amplifier as one embodiment of the present invention. In FIG. 9, an input wave X is input to an input terminal 7 as an input signal. This input wave X
Are input to the input terminals 201 of the approximate solution circuit 1 for y and the 90-degree hybrid circuit 2 respectively.

The approximate solution circuit 1 is constituted by an analog circuit including a limiter amplifier 11 and a subtractor 12, and the input wave X passes through the limiter amplifier 11, and the output of the limiter amplifier 11 and the input wave X
Is subtracted by the subtractor 12 to calculate an approximate solution of y.

Here, the approximate solution circuit 1 calculates the orthogonal wave Y such that a vector composite wave of the input wave X and the input wave X has a constant amplitude.
Is an approximate circuit for obtaining the magnitude of the auxiliary wave as an auxiliary wave. The constant amplitude of the vector composite wave of the input wave X and its orthogonal wave Y means that the vector locus of the vector composite wave follows a circle indicated by a dotted line (b) in FIG. The circuit 1 approximately generates the characteristic (b) of the circle with a simple analog circuit, and the characteristic (a) indicated by a solid line in FIG. 10 is the input / output characteristic of the approximate solution circuit 1. .

That is, since the input / output characteristics of the limiter amplifier 11 in the approximate solution circuit 1 are as shown by (c) in FIG. 11, the output of the limiter amplifier 11 is subtracted from the input wave X by the subtractor.
By subtracting at 12, a characteristic as shown in FIG. 10 (a) is obtained. Since the auxiliary wave Y from the approximate solution circuit 1 has the same phase as the input wave X, the circuit at the subsequent stage rotates the phase by 90 degrees by the phase shift means to change the phase relationship with the input wave X. They are orthogonal.

The auxiliary wave Y of the approximate solution circuit 1 is input to the other input terminal 202 of the 90-degree hybrid circuit 2. The 90-degree hybrid circuit 2 divides the signal input to each input terminal into two, and outputs the signals in the same direction (between terminals 201 and 203, or between terminals 202 and 204).
Between the common mode component and the cross direction output terminals (terminals 201 and 2).
Between the output terminals 203 and 204) or between the terminals 202 and 203). At each of the output terminals 203 and 204, the input signal input to each of the two input terminals 201 and 202 is output. Are phase-shifted by 90 degrees and vector-combined and output. In this embodiment, the two output terminals 203 and 204 output constant envelope waves A and B having a constant envelope and equal amplitude, respectively.

The constant-amplitude waves A and B are respectively the amplifiers 4 having the amplification degree k,
5 is input. Since the input signals have a constant amplitude as these amplifiers 4 and 5, a highly efficient non-linear amplifier such as a class C amplifier can be used.

Outputs kA and kB of the amplifiers 4 and 5 are input to two input terminals 301 and 302 of the -90 degree hybrid circuit 3, respectively. The -90 degree hybrid circuit 3 has a phase rotation angle of -90.
This is the same as the above-described 90-degree hybrid circuit 2 except for the degree. An output wave kX obtained by amplifying the input wave X by k times is output from one output terminal 303 of the -90 degree hybrid circuit 3, and an output auxiliary wave kY obtained by amplifying the auxiliary wave Y by k times is output from the other output terminal 304. Output, output auxiliary wave
kY is terminated by a terminating resistor 6.

The operation of this embodiment circuit will be described below with reference to FIG. FIG. 12 is a vector representation of the state of each signal of the circuit of the embodiment.

Assuming that a signal wave having a magnitude of 2X is input as an input wave, the approximate solution circuit 1 obtains an auxiliary wave 2Y from the input wave 2X according to the characteristic (a) in FIG. To send to. In the 90 degree hybrid circuit 2,
On the output terminal 203 side, a constant amplitude wave A obtained by vector-synthesizing the auxiliary wave Y of the approximate solution circuit 1 rotated by 90 degrees with respect to the input wave X.
Is generated and output. On the other hand, on the output terminal 204 side,
A constant-amplitude wave B is generated and output by vector-compounding the input wave X rotated by 90 degrees and the auxiliary wave Y of the approximate solution circuit 1. These constant amplitude waves A and B have the same amplitude. That is, | A | = | B |.

These constant amplitude waves A and B are then amplified by amplifiers 4 and 5, respectively, to obtain amplified outputs kA and kB, which are input to the -90 degree hybrid circuit 3, respectively.

In the −90-degree hybrid circuit 3, the input amplified output
Synthesize kA and kB. That is, at the output terminal 303, the amplified output
The output wave 2kX, which is the amplified output of the input wave 2X, is obtained by combining Ak and the amplified output kB rotated by -90 degrees to cancel the orthogonal wave component. At the output terminal 304, the amplified output kB and-
The output auxiliary wave 2kY is obtained by combining the amplified output kA rotated by 90 degrees and canceling the component of the input wave X.

According to the above configuration, the circuit configuration for generating the constant amplitude waves A and B can be configured by a simple analog circuit including the approximate solution circuit 1 and the 90-degree hybrid circuit 2. Small size, low power consumption, and high-speed operation can be achieved.

 FIG. 13 shows another embodiment of the present invention.

In this embodiment, the auxiliary wave Y ₀ of the approximate solution circuit 1 is shifted by a 90-degree phase shifter 15.
To generate an auxiliary wave Y orthogonal to the input wave X, input the auxiliary wave Y and the input wave X to the in-phase (or opposite-phase) hybrid circuit 13, and further connect the final-stage hybrid circuit to the 90-degree hybrid circuit. In this configuration, the signals input to the amplifiers 4 and 5 can be the constant amplitude waves A and B, as in the above-described embodiment. From 14, an output wave kX obtained by amplifying the input wave X can be obtained.

Various modifications are possible in implementing the present invention. For example, in the above two embodiments, the auxiliary wave Y of the input wave X is approximately obtained by the approximate solution circuit 1. However, since the auxiliary wave Y is an approximate operation value, the distortion component included in the final amplified output is obtained. Is expected to be larger. Therefore, it is appropriate to add a circuit for reducing this distortion component, and various embodiments of the present invention to which such a correction circuit is added will be described below.

FIG. 14 shows one embodiment of such a distortion correction type constant amplitude wave synthesis type amplifier. In the figure, the basic configuration including the approximate solution circuit 1, the 90-degree phase shifter 15, the hybrid circuits 13, 14, the amplifiers 4, 5, and the like is the same as that shown in FIG.

The difference from the circuit of FIG. 13 is that an adder 18 is provided in the signal path of the input wave X, and the output signal wave kX from the hybrid circuit 14 is supplied to a subtractor 17 via a 1 / k attenuator 16. The subtracter 17 obtains a difference (corresponding to a distortion component Δ) between the input wave that has passed through the adder 18 and the output wave kX that has passed through the attenuator 16. It is configured to add to the wave X.

 The operation of this embodiment circuit will be described below.

Now, it is assumed that the distortion kΔ has occurred in the output wave kX due to the approximate output of the approximate solution circuit 1. The output wave including the distortion kΔ (that is, kX + kΔ) is reduced by 1 / k in the attenuator 16 and input to the subtractor 17, and the difference from the input wave X is obtained by the subtracter 17, thereby extracting the distortion component Δ. You. This distortion component Δ is added to the output wave kX of the hybrid circuit 14 by the adder 18.
Is added to the input wave X with a polarity such that the distortion component kΔ in the above is canceled. As a result, the distortion of the output wave kX, which is the final amplified output, is reduced.

FIG. 15 shows another embodiment of a distortion correction type constant amplitude wave synthesis type amplifier. The embodiment of FIG. 15 has basically the same configuration as that of the embodiment of FIG.
In the embodiment of FIG. 14, an attenuator is used to extract the distortion component Δ.
While the difference between the output wave kX via the input wave 16 and the input wave via the adder 18 is calculated, the output kX via the attenuator 16 and the difference between the output wave kX via the adder 18 are input to the adder 18. The distortion component Δ is detected by obtaining the difference from the previous input wave X, and this detection output is used as the distortion kΔ in the output wave kX.
Is adjusted by the amplifier 22 to an appropriate size that can cancel the input wave X and added to the input wave X by the adder 18. Other operations are basically the same as those in the embodiment of FIG.

FIG. 16 shows still another embodiment of the distortion correction type constant amplitude wave synthesis type amplifier. This embodiment is different from the above-described two embodiments of the distortion correction type in that each of the above-described embodiments has an output wave kX.
Is extracted from the output wave kX, and a correction value is added to the input wave X so that the distortion component kΔ is canceled out.
Detects the distortion contained in the output auxiliary wave kY output from 14, and
It is that by adding the correction value to the auxiliary wave Y ₀ of the approximate solution circuit 1 so as to reduce the distortion.

In other words, between the signal path from the approximate solution circuit 1 to the 90-degree phase shifter 15, an auxiliary wave adder 26 for adding the correction value to the Y ₀ is inserted, the output auxiliary wave kY output from the hybrid circuit 14 Is guided to a subtractor 24 via a 1 / k attenuator 23, the difference from the auxiliary wave output from the adder 26 is calculated by the subtracter 24, and the difference value is adjusted to an appropriate size by an amplifier 25. The adder 26 adds the adjusted correction value Δ to the auxiliary wave Y ₀ , thereby reducing the distortion component in the output auxiliary wave kY of the hybrid circuit 14.

Here, the magnitude of the correction value Δ is adjusted so as to be a deviation Δ ′ between the input / output characteristic (a) of the approximate solution circuit 1 and the ideal circular characteristic (b) in the characteristic diagram of FIG. By adding this correction value Δ ′ to the auxiliary wave Y ₀ , the input / output characteristics of the approximate solution circuit 1 including this correction circuit are equivalently made to ideal circular characteristics, thereby being output from the hybrid circuit 13. This is to reduce the distortion of the output auxiliary wave kY of the hybrid circuit 14 by accurately setting the amplitudes of the constant amplitude waves A and B to a constant amplitude. When the distortion of the output auxiliary wave kY is reduced, the output signal wave kX
Is also reduced.

FIG. 17 shows still another embodiment of the distortion correction type constant amplitude wave synthesis type amplifier. This embodiment is similar to the embodiment of FIG. 16, but by adding the correction value delta 'in the auxiliary wave Y ₀ of the approximate solution circuit 1 is intended to reduce the distortion components in the output auxiliary wave kY hybrid circuit 14, the difference that the auxiliary wave Y ₀ from the approximate solution circuit 1 directly in this example (i.e. adder 26
Not the output side), input to the subtracter 27 and the attenuator 23
Compared to the output auxiliary wave kY through on the basis of the difference 'generates, this correction value delta' correction value delta points are added to the auxiliary wave Y ₀ from the approximate solution circuit 1 at the adder 26 It is. The principle of distortion reduction in this embodiment is basically the same as that in the embodiment of FIG.

FIG. 18 shows still another embodiment of the distortion correction type constant amplitude wave synthesis type amplifier. In this embodiment, the magnitude of the auxiliary wave Y of the approximate solution circuit 1 is adjusted using an automatic gain control (AGC) amplifier to reduce distortion.

9 is used as the basic circuit configuration. An AGC amplifier 30 is provided on the output side of the approximate solution circuit 1 of the circuit of FIG. After passing through the attenuator 23, kX is squared by the squaring circuit 32 and guided to the subtractor 33. In the subtracter 33, the difference Δ from the squared input wave X by the squaring circuit 31 is taken, and this difference Δ is calculated. The DC component is extracted by passing through a low-pass filter 34 and used as a control voltage for the AGC amplifier 30.

In this embodiment, the size of the auxiliary wave Y of the approximate solution circuit 1 is adjusted by the AGC amplifier 30 so that the linearity of the output wave kX with respect to the input wave X is maintained.

That is, if the auxiliary wave from the approximate solution circuit 1 is on the circular characteristic (b) in FIG. 10, the output wave kY output from the hybrid circuit 3 should theoretically have no distortion. The distortion component included in the output wave kX is extracted by the subtractor 33, and the gain of the AGC amplifier 30 is adjusted so that the distortion component becomes zero. (B) The size is adjusted as shown above.

FIG. 19 shows still another embodiment of the distortion correction type constant amplitude wave synthesis type amplifier. This embodiment also adjusts the size of the auxiliary wave Y of the approximate solution circuit 1 by the AGC amplifier.

That is, the AGC amplifier 30 is arranged on the output side of the approximate solution circuit 1, and the constant amplitude waves A,
A value obtained by squaring either one of B by a squaring circuit 35 is led to a subtractor 36, which calculates a difference from a constant value V _0, and converts the difference into a control voltage by passing through a low-pass filter 37. Then, the gain of the AGC amplifier 30 is adjusted by the control voltage.

The principle of operation of this embodiment is that the envelope of the constant amplitude waves A and B output from the hybrid circuit 2 when the input / output characteristics of the approximate solution circuit 1 are the ideal circular characteristics (b) in FIG. If the amplitude is exactly a constant value, but the input / output characteristics of the approximate solution circuit 1 are approximate characteristics (a), the amplitudes of the constant amplitude waves A and B are exactly constant. The subtractor 36 compares the square value of the amplitude of the constant amplitude wave A or B with a predetermined constant value V ₀ to determine the difference, and the AGC amplifier is set so that the difference becomes zero. The gain of 30 is adjusted so that the auxiliary wave Y of the approximate solution circuit 1 has a circular characteristic (b). Thus, the constant amplitude waves A and B
Can always be constant, and when these are constant, no distortion appears in the output wave kX of the hybrid circuit 3.

FIG. 20 shows still another embodiment of the distortion correction type constant amplitude wave synthesis type amplifier. In this embodiment, the magnitude of the auxiliary wave Y of the approximate solution circuit 1 is adjusted by an AGC amplifier as in the circuits of FIGS. 18 and 19. As a difference, in this embodiment, the circuit of FIG. 18 controls the AGC amplifier 30 by comparing the input wave X and the output wave kX to generate a control voltage, whereas the circuit of FIG. Compare the auxiliary wave Y of the solution circuit 1
The AGC amplifier 30 is controlled.

That is, the output auxiliary wave kY of the hybrid circuit 3 is guided to the subtractor 39 via the attenuator 23 and the squaring circuit 38, while the auxiliary wave Y of the approximate solution circuit 1 is guided to the subtractor 39 via the squaring circuit 40, Here, the difference between the two is taken and this is used as a low-pass filter.
41 to convert it to a control voltage.
By controlling the gain of the amplifier 30, the auxiliary wave Y of the approximate solution circuit 1 is placed on the circular characteristic (b) in FIG.

FIG. 21 shows an application example of the present invention. In the figure, reference numeral 50 denotes a constant-amplitude wave combining type amplifier circuit according to any of the above-described embodiments of the present invention. Reference numerals 51 and 52 denote non-linear amplifiers such as class C amplifiers.
Constant amplitude waves A and B (or kA, k after amplification)
B) Amplify each. 53 is amplified constant amplitude wave mA, m
This is a hybrid circuit that combines B to generate an amplified output mX.

With such a circuit configuration, the input wave X can be amplified by the nonlinear amplifiers 51 and 52 separately from the amplifier circuit including the closed loop for performing the distortion correction.
The efficiency of amplification is improved.

In any of the above embodiments, the approximate solution circuit is constituted by the circuit including the limiter amplifier 1 and the subtractor 12, but the present invention is not limited to this, and the
Various other forms of analog circuits can be employed as long as the input / output characteristics approximate to the circle specification (b) shown in FIG.

[Effects of the Invention] According to the present invention, an arithmetic circuit for generating a constant-amplitude wave by a small-scale, low-power, high-speed operation analog circuit is configured, so that a conventional digital signal processing circuit is used. Power consumption, miniaturization, and high-speed operation as compared with the constant-amplitude wave synthesis type amplifier.

[Brief description of the drawings]

1 to 8 are explanatory diagrams each showing the principle of a constant amplitude wave combining amplifier according to the present invention, FIG. 9 is a block diagram showing a constant amplitude wave combining amplifier as one embodiment of the present invention, and FIG. Is an input / output characteristic diagram of the approximate solution circuit in the embodiment, FIG. 11 is an input / output characteristic diagram of the limiter amplifier of the approximate solution circuit in the embodiment, FIG. 12 is a diagram for explaining the operation of the embodiment, FIG. FIG. 14 is a block diagram showing another embodiment of the present invention, and FIGS. 14 to 20 are block diagrams showing a constant-amplitude wave synthesis type amplifier of the present invention to which a correction circuit for reducing distortion is added, respectively. FIG. 22 is a block diagram showing an application example of the present invention, and FIG. 22 is a block diagram showing a conventional constant-amplitude wave combining amplifier. In the figure, 1... Approximate solution circuit 2, 3, 13,... Hybrid circuit 4, 5... Non-linear amplifier 6... Terminating resistor 11 ... limiter amplifier 12, 17, 27, 33, 36, 39. Subtractor 15 90-degree phase shifter 16, 23 1 / k attenuator 18, 26 Adder 22, 25 Amplifier 30 AGC amplifier 31, 32, 35, 38, 40 Squared Circuits 34, 37, 41: Low-pass filter

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshimasa Odo 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Kazuhiko Kobayashi 1015 Ueodanaka, Nakahara-ku Nakagawa-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited ( 72) Inventor, Shuhaku Kobayakawa, Fujitsu Limited, 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture (72) Inventor Toru 1015, Kamodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (56) References JP 3-99507 (JP, A) JP-A-3-96004 (JP, A) JP-A-1-284106 (JP, A) US Patent 3,990,742 (US, A) US Patent 4,490,684 (US, A) (58) Field (Int.Cl. ⁶ , DB name) H03F 1/00-3/00 H03G 1/00-3/00

Claims (8)

(57) [Claims] An auxiliary wave generating circuit (81) comprising an analog circuit for generating an auxiliary wave for generating a constant amplitude wave by approximately calculating from the input signal wave by combining the input signal wave with the input signal wave.
A constant amplitude wave generating circuit (82) comprising an analog circuit that generates two constant amplitude waves by combining the auxiliary wave of the auxiliary generating circuit (81) and the input signal wave; Two amplifiers (83, 84) for separately amplifying the two constant amplitude waves output from the generation circuit (82)
And a combining circuit (85) that combines the constant amplitude waves amplified by the two amplifiers (83, 84) to generate an output signal wave. 2. An auxiliary wave generation circuit (81) comprising an analog circuit for generating an auxiliary wave for generating a constant amplitude wave by approximately calculating from the input signal wave by combining the input signal wave with the input signal wave.
A constant amplitude wave generating circuit (82) comprising an analog circuit for generating two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generating circuit (81) and the input signal wave; Two amplifiers (83, 84) that separately amplify the two constant amplitude waves output from the wave generation circuit (82)
A combining circuit (85) that combines the constant amplitude waves respectively amplified by the two amplifiers (83, 84) to generate an output signal wave; and outputs the output signal wave of the combining circuit (85) to the input signal. A distortion component in the output signal wave is compared with the output signal wave, a correction value is generated based on the detected output to cancel the distortion of the output signal wave of the synthesis circuit, and is added to the input signal wave. )
A constant-amplitude wave synthesis type amplifier comprising: 3. An auxiliary wave generation circuit (81) comprising an analog circuit for generating an auxiliary wave for generating a constant amplitude wave by approximately calculating from the input signal wave by combining the input signal wave with the input signal wave.
A constant amplitude wave generating circuit (82) comprising an analog circuit for generating two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generating circuit (81) and the input signal wave; Two amplifiers (83, 84) that separately amplify the two constant amplitude waves output from the wave generation circuit (82)
A combining circuit (87) for combining the constant-amplitude waves amplified by the two amplifiers (83, 84) to generate an output signal and an output auxiliary wave, and an output auxiliary from the combining circuit (87). The wave is compared with the auxiliary wave of the auxiliary wave generation circuit (81) to detect a distortion component in the output auxiliary wave, and a correction value for canceling the distortion of the output auxiliary wave is generated based on the detected output to generate the correction value. A constant-amplitude wave synthesis type amplifier comprising: a correction circuit (88) for adding to the auxiliary wave of the wave generation circuit (81). 4. An auxiliary wave generating circuit (81) comprising an analog circuit for generating an auxiliary wave for generating a constant amplitude wave by approximately calculating from the input signal wave by combining with an input signal.
A constant amplitude wave generating circuit (82) comprising an analog circuit for generating two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generating circuit (81) and the input signal wave; Two amplifiers (83, 84) that separately amplify the two constant amplitude waves output from the wave generation circuit (82)
A combining circuit (85) that combines the constant amplitude waves amplified by the two amplifiers (83, 84) to generate an output signal wave; and a magnitude of the auxiliary wave from the auxiliary wave generating circuit (81). A variable gain amplifier (89) for variably adjusting the output signal wave; comparing the output signal wave of the combining circuit (85) with the input signal wave to detect a distortion component in the output signal wave; And a control circuit (90) for controlling the gain of the variable gain amplifier (89) so as to cancel the distortion of the output signal wave of (85). 5. An auxiliary wave generation circuit (81) comprising an analog circuit for generating an auxiliary wave for generating a constant amplitude wave by approximately calculating from the input signal wave by combining the input signal wave with the input signal wave.
A constant amplitude wave generating circuit (82) comprising an analog circuit for generating two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generating circuit (81) and the input signal wave; Two amplifiers (83, 84) that separately amplify the two constant amplitude waves output from the wave generation circuit (82)
A combining circuit (85) that combines the constant amplitude waves amplified by the two amplifiers (83, 84) to generate an output signal wave; and a magnitude of the auxiliary wave from the auxiliary wave generating circuit (81). A variable gain amplifier (89) for variably adjusting the amplitude and a variable gain amplifier such that the constant amplitude wave of the constant amplitude wave generating circuit (82) is compared with a predetermined reference value so that the constant amplitude wave has a constant amplitude. And a control circuit (91) for controlling the gain of (89). 6. An auxiliary wave generation circuit (81) comprising an analog circuit for generating an auxiliary wave for generating a constant amplitude wave by approximately calculating from the input signal wave by combining the input signal wave with the input signal wave.
A constant amplitude wave generating circuit (82) comprising an analog circuit for generating two constant amplitude waves by combining the auxiliary wave of the auxiliary wave generating circuit (81) and the input signal wave; Two amplifiers (83, 84) that separately amplify the two constant amplitude waves output from the wave generation circuit (82)
A combining circuit (87) that combines the constant-amplitude waves amplified by the two amplifiers (83, 84) to generate an output signal wave and an output auxiliary wave; A variable gain amplifier (89) that variably adjusts the size of the auxiliary wave; and outputs the auxiliary wave of the combining circuit (87) to the auxiliary wave generation circuit (8).
A distortion component in the output auxiliary wave is detected by comparing with the auxiliary wave of 1), and the gain of the variable gain amplifier (89) is canceled based on the detected output so as to cancel the distortion of the output auxiliary wave of the combining circuit (87). And a control circuit (92) for controlling a constant amplitude wave synthesis type amplifier. 7. Two more second amplifiers (93, 94) for amplifying the constant amplitude waves of the two amplifiers (83, 84), respectively, and the two second amplifiers (93, 94) respectively. 7. A constant amplitude wave synthesizing circuit according to claim 1, further comprising a second synthesizing circuit (95) for synthesizing the amplified constant amplitude wave to generate an amplified output signal wave. amplifier. 8. The auxiliary wave generation circuit (81) passes an input signal wave to a limiter circuit (911), and the limiter circuit (911)
An auxiliary wave is calculated by taking a difference between the output of the input signal wave and the input signal wave by a differentiator (912).
8. The constant-amplitude wave combining amplifier according to any one of 7.