JP3385703B2 - Distortion compensation circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distortion compensating circuit for compensating for non-linear distortion generated in an output signal of a high frequency amplifier or the like.

[0002]

2. Description of the Related Art In a high power amplifier (HPA) for communication,
In order to compensate the distortion component resulting from the non-linearity of the amplifier,
Distortion compensation circuits are often used. There are various circuit configurations of the distortion compensating circuit, but roughly classified, the predistortion type that is installed in the front stage of the amplifier to be compensated for distortion and uses the output signal of the distortion compensating circuit as the input signal of the amplifier,
There are two types of feed-forward type which compensate distortion by combining the output signal of the amplifier for which distortion is to be compensated with the output signal of the distortion compensation circuit. Of the two, the predistortion type is often used from the viewpoint of power efficiency. For example, FIG. 10 shows the IEICE Spring Conference (1991, C-
FIG. 53 is an equivalent circuit diagram of the conventional predistortion type distortion compensation circuit shown in FIG. In the figure, a first amplifier 26, a first attenuator 28, and a first power divider 40 are sequentially connected to a first output terminal 34 of a first hybrid coupler 30, and a second output terminal 34 is connected to a second output terminal 34 of the first hybrid coupler 30. The second attenuator 29, the second amplifier 27, and the second power distributor 41 are sequentially connected to the output terminal 35, and the first and second power distributors 4 are connected.
One output signal of each of 0 and 41 is combined by the second hybrid coupler 31, a first variable attenuator 42 is connected to the second hybrid coupler 31, and the second power distribution The other output signal of the device 41 is
The output signals of the first variable attenuator and the third hybrid coupler pass through the second variable attenuator 43 and the third hybrid coupler 32, and are combined by the fourth hybrid coupler 33. . This distortion compensating circuit is composed of a strip line on a dielectric substrate, and uses a field effect transistor for an amplifier and a resistor sheet made of tantalum nitride or the like for an attenuator.

Next, the operation will be described. A modulation signal or a high frequency signal including a plurality of carrier waves is distributed to the first and second output terminals 34 and 35 with an equal amplitude and a phase difference of 90 °. The amplitude characteristic of the amplifier 26 becomes like the curve G shown in FIG. 11A, while the amplitude characteristic of the amplifier 27 becomes like the curve H due to the attenuator 29 in the preceding stage. First
The output of the amplifier of FIG. 2 is represented by the attenuator 28 as shown by the curve I, and the output signals of the power dividers 40 and 41 are bisected by equal amplitude and in-phase, respectively, and the terminals 36 and 37 are represented by the curves H and I, respectively. Since signals having characteristics described above are obtained and these are combined in antiphase, the amplitude characteristic shown by the curve J is obtained at the output terminal 38. At the terminal 39, the output of the amplifier 27 is
The amplitude characteristic is obtained through the power distributor 41 and the hybrid coupler 32 and is shown by the curve H. Since the amplitude characteristic of the terminal 38 shown by the curve J and the amplitude characteristic of the terminal 39 shown by the curve H are combined in phase at the output terminal 2, the amplitude characteristic of the entire distortion compensation circuit is shown in FIG.
As shown by the curve K in (b), as the input power increases, the characteristic changes from the linear region to the warp region and then to the saturation region. In general, the amplitude characteristic of a high-frequency amplifier reaches a saturation region through a warp region where the amplitude change is gradually suppressed from a linear region as the input signal increases, as shown by a curve E in FIG. 2B. . On the other hand, the distortion compensating circuit has an opposite amplitude characteristic, that is, a warp region as shown by the curve D, and the output signal of the distortion compensating circuit is used as the input signal of the high frequency amplifier. The amplitude characteristic shown by the curve E can be compensated to the ideal amplitude characteristic shown by the curve F, that is, the characteristic that the linearity is maintained until immediately before the saturation region.

[0004]

Since the conventional distortion compensating circuit is constructed as described above and uses a large number of couplers and attenuators, there is a problem that the entire distortion compensating circuit becomes very large. there were. Further, since many modules are used, there is a problem that fine adjustment of the output signal is complicated and difficult according to the characteristics of various amplifiers for which distortion should be compensated. Furthermore, since a large number of attenuators and distributors are combined, the loss of the entire distortion compensation circuit is very large, and it is necessary to increase the gain or the number of stages of the amplifier connected in the subsequent stage. There was also the problem of reduced efficiency. Further, since many couplers are used, there is a problem that the usable frequency band is narrowed.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain a distortion compensation circuit which is small in size, allows easy fine adjustment of an output signal, has less loss, and has a wide band. I am trying.

[0006]

The distortion compensating circuit according to the first embodiment of the present invention is one in which two couplers having a mutual passing phase difference of 180 ° are added to the input ends of a combining circuit. is there.

[0007]

In the distortion compensating circuit according to the third embodiment of the present invention, two field effect transistors having different gate widths are added to the output terminals of the distribution circuit.

Furthermore, the distortion compensating circuit according to the fourth embodiment of the present invention uses a dual gate field effect transistor for at least one of the amplifiers added to the two output terminals of the distribution circuit.

Further, the distortion compensating circuit according to the fifth embodiment of the present invention has a configuration in which one of the amplifiers added to the two output terminals of the distribution circuit is connected to the other amplifier in a plurality of stages.

[0011]

Further, the distortion compensating circuit according to the seventh embodiment of the present invention uses a distribution circuit for distributing an input signal with an appropriate amplitude ratio and in-phase.

[0013]

[0014]

In the distortion compensating circuit according to the first embodiment of the present invention, the output signals of the two amplifiers having different operation levels due to the attenuators are combined in opposite phases by using the two couplers. An output signal having a warp amplitude characteristic is obtained to compensate for the non-linearity of the amplifier connected in the subsequent stage.

[0015]

In the distortion compensating circuit according to the third embodiment of the present invention, the output signals of the two field effect transistors having different gate widths are combined in opposite phases by using the two couplers. An output signal having a warp amplitude characteristic is obtained to compensate for the non-linearity of the amplifier connected in the subsequent stage.

Further, in the distortion compensating circuit according to the fourth embodiment of the present invention, the output signals of the two amplifiers, at least one of which is a dual gate field effect transistor, are connected to two couplers while adjusting the second gate voltage. By utilizing them and synthesizing in opposite phases, an output signal having an amplitude characteristic of upward warp is obtained, and the nonlinearity of the amplifier connected in the subsequent stage is compensated.

Further, in the distortion compensating circuit according to the fifth embodiment of the present invention, the output signals of the two amplifiers, one of which is a configuration in which the other amplifier is connected in a plurality of stages, are mutually inverted by using two couplers. By synthesizing in phases, an output signal having a warp amplitude characteristic is obtained, and the non-linearity of the amplifier connected in the subsequent stage is compensated.

[0019]

Further, in the distortion compensating circuit according to the seventh embodiment of the present invention, an input signal is distributed by a distribution circuit with an unbalanced amplitude ratio, and output signals of two amplifiers having different operation levels are combined into two couplers. Are used to combine the signals in opposite phases to obtain an output signal having a warp amplitude characteristic and compensate for the non-linearity of the amplifier connected in the subsequent stage.

[0021]

[0022]

【Example】

Example 1. An embodiment of the distortion compensation circuit according to the first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an equivalent circuit diagram of a distortion compensation circuit according to the present invention. 1 is an input terminal, 2
Is an output terminal, and the first output terminal 4 of the distribution circuit 3 is formed of a first amplifier 6, a first attenuator 8 and a quarter wavelength strip line having an open end. A first coupler 10 is connected in sequence, and a second attenuator 9, a second amplifier 7, and a quarter wavelength having a short-circuited end are connected to the second output terminal 5 of the distribution circuit 3. The second couplers 11 formed of strip lines are sequentially connected, and the first and second couplers 10 and 11 are connected to the first and second input terminals 13 and 14 of the combining circuit 12, respectively. ing. The distribution circuit 3 and the synthesis circuit 12 are of the Wilkinson type or the resistance division type.

Next, the operation will be described. Input terminal 1
The signal input from is distributed to the output terminals 4 and 5 with the same amplitude and the same phase, and the output of the first amplifier 6 has the amplitude characteristic shown by the curve A in FIG. The output of the second amplifier 7 has the amplitude characteristic shown by the curve B by the second attenuator 9 installed in the preceding stage. Further, the output of the first amplifier 6 shown by the curve A has the amplitude characteristic as shown by the curve C by the first attenuator 8. The curves B and C
The output signal having the amplitude characteristic shown by passes through the couplers 10 and 11 whose passing phases are different from each other by 180 °, and the combiner 1
2, the output signal of the distortion compensating circuit has an amplitude characteristic having an upward warping curve as the input signal increases, as shown by the curve D in FIG. Generally, a high frequency amplifier has a structure as shown by a curve E in FIG.
This is an amplitude characteristic having a warp region in which the amplitude of the output signal is suppressed as the input signal increases. In the warp region and the saturation region where the amplitude of the output signal is suppressed, the amplifier performs a non-linear operation, so that a distortion component is generated in the output signal. When the output signal of the distortion compensating circuit indicated by the curve D is used as the input signal of the high frequency amplifier having the amplitude characteristic of the curve E to compensate for distortion, the output signal of the high frequency amplifier is the curve F. As shown, it has an ideal amplitude characteristic with good linearity just before the saturation region,
As a result, the distortion component generated from the high frequency amplifier is minimized.

Example 2. An embodiment of the distortion compensation circuit according to the second embodiment of the present invention will be described below with reference to the drawings. Figure 3
FIG. 4 is an equivalent circuit diagram of the distortion compensation circuit according to the present invention, in which the pass phase amount is set between the first coupler 10 and the input end 13 of the first combining circuit in the circuit shown in the first embodiment. The phase shifter 15 for changing is provided.

Next, the operation will be described. The operation of the distortion compensating circuit having this configuration and the amplitude characteristic of the output signal are the same as those in the first embodiment. However, in this circuit configuration, the first coupler 10
And the input terminal 13 of the first combining circuit, a phase shifter 15
2 is installed, it is possible to finely adjust the phase difference when combining two signals at the first and second input terminals 13 and 14 of the combining circuit 12 shown by the curves C and B in FIG. 2A. Therefore, it is possible to set the output signal indicated by the curve D to the optimum characteristic according to the characteristic of the high-frequency amplifier that is connected in the subsequent stage and whose distortion is to be compensated. The process of compensating for the non-linearity of the amplifier connected in the subsequent stage by using the output signal of the distortion compensation circuit is the same as that of the first embodiment, as shown in FIG.

Example 3. An embodiment of the distortion compensation circuit according to the third embodiment of the present invention will be described below with reference to the drawings. Figure 4
FIG. 6 is an equivalent circuit diagram of a distortion compensation circuit according to the present invention. 1
Is an input terminal, 2 is an output terminal, and the first output terminal 4 of the distribution circuit 3 has a first field effect transistor 16 and
A first coupler 10 formed of a quarter-wave strip line having an open end is sequentially connected, and the second output terminal 5 of the distribution circuit 3 is connected to the first field effect transistor 16 and Are sequentially connected to a second field effect transistor 17 having a different gate width and a second coupler 11 formed of a quarter-wave strip line having a short-circuited end. The first and second couplers 10 and 11 are connected to the input terminals 13 and 14, respectively. The distribution circuit 3 and the synthesis circuit 12 are of the Wilkinson type or the resistance division type.

Next, the operation will be described. Input terminal 1
The signal input from is distributed to the output terminals 4 and 5 with the same amplitude and the same phase, but in this circuit configuration, the first and second amplifiers have different gate widths, low gain, and large saturated output. By using the first field-effect transistor 16 and the second field-effect transistor 17 having a high gain and a small saturation output, respective outputs can be obtained as shown in FIG.
Can be set like the curves B and C in. The first coupler 10 and the second coupler 11 have pass phases of 180 ° with respect to each other.
Since they are different, the output signal from the synthesizing circuit 12 becomes like a curve D. The process of compensating the non-linearity of the amplifier connected in the subsequent stage by using the output signal indicated by the curve D is the same as that of the first embodiment, as shown in FIG.

Example 4. An embodiment of the distortion compensation circuit according to the fourth embodiment of the present invention will be described below with reference to the drawings. Figure 5
FIG. 6 is an equivalent circuit diagram of a distortion compensation circuit according to the present invention. 1
Is an input terminal and 2 is an output terminal. The first output terminal 4 of the distribution circuit 3 has a dual gate field effect transistor 18 whose gain can be finely adjusted by the voltage of the second gate applied to the terminal 19. , A first coupler 10 formed of a quarter-wave strip line having an open end is sequentially connected, and a second amplifier 7 is short-circuited to a second output terminal 5 of the distribution circuit 3. A second coupler 11 formed of a quarter wavelength strip line having an end is sequentially connected, and the first and second input terminals 13 and 14 of the combining circuit 12 are connected to the first and second input terminals 13 and 14, respectively. Couplers 10 and 11 are connected to each other. The distribution circuit 3 and the synthesis circuit 12 are of the Wilkinson type or the resistance division type.

Next, the operation will be described. Input terminal 1
2 is distributed to the output terminals 4 and 5 with the same amplitude and the same phase, and the output signal of the second amplifier 7 is shown in FIG.
In contrast to the amplitude characteristic shown by the curve B in FIG.
The voltage of the second gate applied to can be adjusted and set as shown by the curve C. First coupler 10 and second coupler 11
Because the passing phases differ from each other by 180 °, the combining circuit 1
The output signal from 2 has an amplitude characteristic as shown by the curve D. The process of compensating for the non-linearity of the amplifier connected to the subsequent stage by the output signal of the curve D is the same as that of the first embodiment shown in FIG. Further, in this configuration circuit, the voltage applied to the second gate can be adjusted to vary the curve C of FIG. 2A, which is the output signal of the dual gate field effect transistor 18. Therefore, the amplitude ratio between the curves B and C, which are the two signals combined by the combining circuit 12, can be electrically finely adjusted, and the output signal shown by the curve D can be adjusted according to the characteristics of the high-frequency amplifier whose distortion is to be compensated. , It is possible to have optimum characteristics.

Example 5. An embodiment of the distortion compensation circuit according to the fifth embodiment of the present invention will be described below with reference to the drawings. Figure 6
FIG. 6 is an equivalent circuit diagram of a distortion compensation circuit according to the present invention. 1
Is an input terminal, 2 is an output terminal, and the first output terminal 4 of the distribution circuit 3 has a first amplifier 6 and a first quarter-wave strip line having an open end. Coupler 1
0 are sequentially connected, and the second output terminal 5 of the distribution circuit 3 is connected.
Has a configuration in which the first amplifier is connected in a plurality of stages,
The second amplifier 20, the first attenuator 8, and the second coupler 11 formed of a quarter-wave strip line having a short-circuited end are sequentially connected, and the first and the second of the combining circuit 12 are connected. The first and second couplers 10 and 1 are connected to two input terminals 13 and 14, respectively.
1 are connected to each other. The distribution circuit 3 and the synthesis circuit 12 are of the Wilkinson type or the resistance division type.

Next, the operation will be described. Input terminal 1
The signal input from is distributed to the output terminals 4 and 5 with the same amplitude and the same phase, and the output of the first amplifier 6 has the amplitude characteristic shown by the curve B in FIG. The output of the second amplifier 20 has a higher gain than that of the first amplifier, and therefore has an amplitude characteristic indicated by the curve A. The output of the first amplifier 20 shown by the curve B has an amplitude characteristic as shown by the curve C by the first attenuator 8. The curves B and C
The output signal having the amplitude characteristic shown by passes through the couplers 10 and 11 whose passing phases are different from each other by 180 °, and the combiner 1
2, the output signal of the distortion compensating circuit has the amplitude characteristic as shown by the curve D in FIG. The process of compensating for the non-linearity of the amplifier connected to the subsequent stage by the output signal of the curve D is the same as that of the first embodiment shown in FIG.

Example 6. An embodiment of the distortion compensation circuit according to the sixth embodiment of the present invention will be described below with reference to the drawings. Figure 7
FIG. 6 is an equivalent circuit diagram of a distortion compensation circuit according to the present invention. 1
Is an input terminal, and 2 is an output terminal. A first amplifier 6 and a first attenuator 8 are sequentially connected to a first output terminal 4 of the distribution circuit 3, and a second amplifier of the distribution circuit 3 is connected. A second attenuator 9 and a second amplifier 7 are sequentially connected to the output terminal 5, and the first and second attenuators are connected to the first and second input terminals 13 and 14 of the rat race type synthesizing circuit 21. 8 and the second amplifier 7
Are connected respectively. A Wilkinson type, a resistance division type, or the like is used for the distribution circuit 3.

Next, the operation will be described. Terminal 13,
The process of obtaining the signal having the amplitude characteristic shown by the curves C and B in FIG. 2A in 14 is the same as that in the first embodiment. However, in the present circuit configuration, in the rat-race type synthesizing circuit, the terminal 2 for synthesizing the two signals represented by the curves C and B with equal amplitude and opposite phase is used as the output terminal. It has the amplitude characteristics shown. The process of compensating for the non-linearity of the amplifier connected to the subsequent stage by the output signal of the curve D is the same as that of the first embodiment shown in FIG.

Example 7. An embodiment of the distortion compensation circuit according to the seventh embodiment of the present invention will be described below with reference to the drawings. Figure 8
FIG. 6 is an equivalent circuit diagram of a distortion compensation circuit according to the present invention. 1
Is an input terminal, 2 is an output terminal,
The output terminal 4 of the first amplifier 6 and the first attenuator 8
And a first coupler 10 formed of a quarter-wave strip line having an open end are sequentially connected, and a second amplifier 7 is connected to a second output terminal 5 of the distribution circuit 3. The second formed by a quarter-wave strip line with a short-circuited end
Couplers 11 are sequentially connected, and the first and second couplers 1 are connected to the first and second input terminals 13 and 14 of the synthesizing circuit 12, respectively.
0 and 11 are respectively connected. The synthesis circuit 1
For 2, a Wilkinson type or a resistance division type is used.

Next, the operation will be described. The input signal is in-phase by the distribution circuit 23 and compared with the terminal 5 at the terminal 4
Is distributed so that it has a larger amplitude with an appropriate amplitude ratio,
The amplitude characteristics of the output signals of the first and second amplifiers are as shown by curves A and B in FIG. Curve B
The output of the first amplifier 6 indicated by 1 has an amplitude characteristic as shown by the curve C by the first attenuator 8. The curve B,
Since the output signal having the amplitude characteristic indicated by C passes through the couplers 10 and 11 whose passing phases are different from each other by 180 ° and is combined in the reverse phase in the combiner 12, the output signal of this distortion compensation circuit is The amplitude characteristic is as shown by the curve D. The process of compensating for the non-linearity of the amplifier connected to the subsequent stage by the output signal of the curve D is the same as that of the first embodiment shown in FIG.

Example 8. An embodiment of the distortion compensation circuit according to the eighth embodiment of the present invention will be described below with reference to the drawings. Figure 9
FIG. 6 is an equivalent circuit diagram of a distortion compensation circuit according to the present invention. 1
Is an input terminal, and 2 is an output terminal. The first amplifier 6 and the first attenuator 8 are sequentially connected to the first output terminal 4 of the distribution circuit 24 via the phase shifter 25, Distribution circuit 2
The second amplifier 7 is connected to the second output terminal 5 of the fourth circuit 4, and the first and second input terminals 13 and 14 of the synthesizing circuit 12 are connected.
The first attenuator and the second amplifier 7 are connected to each other. For the synthesizing circuit 12, a Wilkinson type, a resistance division type, or the like is used.

Next, the operation will be described. The input signal is distributed by the distribution circuit 24 such that the terminal 4 is larger than the terminal 5 with a certain appropriate amplitude ratio, and the first and second signals are distributed.
2 (a) shows the amplitude characteristics of the output signal of the amplifier of FIG.
Curves A and B are shown. The output of the first amplifier 6 shown by the curve B has the amplitude characteristic shown by the curve C by the first attenuator 8. Adjust the phase shifter 25,
The output signal having the amplitude characteristic shown by the curves B and C is
The output signals synthesized by the synthesizer 12 by setting the terminals 13 and 14 so as to have opposite phases are
The amplitude characteristics are as follows. The process of compensating for the non-linearity of the amplifier connected to the subsequent stage by the output signal of the curve D is the same as that of the first embodiment shown in FIG.
Further, in this configuration circuit, the phase shifter 25 is used to finely adjust the phase relationship between the curves B and C in FIG. It is possible to set the optimum characteristics according to the characteristics.

[0038]

According to the distortion compensating circuit of the first embodiment of the present invention, the output signals from the two amplifiers having different amplitude characteristics are obtained by using the two couplers having the difference of the passing phases of 180 °. Since the output signals required for distortion compensation are obtained by synthesizing in the opposite phase, it is not necessary to use a complicated circuit as in the conventional example, and the circuit can be downsized.

[0039]

In the distortion compensating circuit according to the third embodiment of the present invention, the amplitude ratio of the two signals to be combined can be adjusted by using the two field effect transistors having different gate widths, so that the distortion compensating circuit is connected to the subsequent stage. The optimum output signal can be obtained according to the characteristics of the amplifier whose distortion should be compensated.

In the distortion compensating circuit according to the fourth embodiment of the present invention, the dual gate field effect transistor is used for at least one of the two amplifiers, and the voltage applied to the second gate of the dual gate field effect transistor is used. Is adjusted, the optimum output signal according to the characteristics of the amplifier to be compensated for distortion, which is connected in the subsequent stage, is electrically adjusted and obtained.

According to the distortion compensating circuit of the fifth embodiment of the present invention, one of the two amplifiers has a multi-stage configuration of the other amplifier, so that the gain of the entire circuit becomes large.
It is possible to reduce the number of amplifier stages connected in the subsequent stage and for which distortion must be compensated.

[0043]

In the distortion compensating circuit according to the seventh embodiment of the present invention, since the distribution circuit that distributes the input signal at a certain amplitude ratio is used, the attenuator is reduced and the loss of the entire circuit is reduced. Since the distortion compensation circuit is driven, the amplifier connected in the previous stage can be reduced.

[0045]

[Brief description of drawings]

FIG. 1 is an equivalent circuit diagram of a distortion compensation circuit showing a first embodiment of the present invention.

FIG. 2 is a diagram showing an operation principle of the distortion compensation circuit of the present invention by an amplitude characteristic with respect to input power.

FIG. 3 is an equivalent circuit diagram of a distortion compensation circuit showing a second embodiment of the present invention.

FIG. 4 is an equivalent circuit diagram of a distortion compensation circuit showing a third embodiment of the present invention.

FIG. 5 is an equivalent circuit diagram of a distortion compensation circuit showing a fourth embodiment of the present invention.

FIG. 6 is an equivalent circuit diagram of a distortion compensation circuit showing a fifth embodiment of the present invention.

FIG. 7 is an equivalent circuit diagram of a distortion compensation circuit showing a sixth embodiment of the present invention.

FIG. 8 is an equivalent circuit diagram of a distortion compensation circuit showing a seventh embodiment of the present invention.

FIG. 9 is an equivalent circuit diagram showing an example of a distortion compensation circuit according to Example 8 of the present invention.

FIG. 10 is an equivalent circuit diagram of a conventional distortion compensation circuit.

FIG. 11 is a diagram showing an operation principle of a conventional distortion compensation circuit by amplitude characteristics with respect to input power.

[Explanation of symbols]

1 input terminal 2 output terminals 3 distribution circuits 4 First output terminal of distribution circuit 3 5 Second output terminal of distribution circuit 3 6 First amplifier 7 Second amplifier 8 First attenuator 9 Second attenuator 10 First coupler 11 Second coupler 12 Compositing circuit 13 First input terminal of synthesis circuit 12 14 Second input terminal of combining circuit 12 15 Phase shifter 16 First field effect transistor 17 Second field effect transistor 18 Dual gate field effect transistor 19 Terminal for applying second gate voltage 20 Second amplifier in which first amplifier 6 is connected in a plurality of stages 21 Rat Race Synthesizer 22 Dummy terminated output terminal 23 distribution circuits 24 Distribution circuit with built-in phase shifter 25 Phase shifter built in distribution circuit 24

Claims (5)

(57) [Claims] 1. The first and second input signals are of equal amplitude and in phase.
And a first amplifier, a first attenuator, and a quarter-wave strip line having an open end at a first output terminal of the distribution circuit. Na
A first coupler and sequentially connected that, also the second of said distribution circuit
A second attenuator, a second amplifier, and a short
The second consisting of a quarter-wave strip line with a junction end
The distortion compensating circuit is characterized in that the above-mentioned couplers are sequentially connected and the output signals of the first and second couplers are connected to a combining circuit for combining them in equal amplitude and in phase. 2. The first and second input signals are of equal amplitude and in phase.
And a first field-effect transistor and a quarter-wave strip line having an open end at a first output terminal of the distribution circuit.
And a second field effect transistor having a gate width different from that of the first field effect transistor, and a short-circuited end at the second output terminal of the distribution circuit.
The second combiner composed of a quarter-wavelength strip line is sequentially connected, and a combining circuit for combining the output signals of the first combiner and the second combiner in equal amplitude and in phase is input. Distortion compensating circuit characterized in that it is connected like this. 3. The first and second input signals are of equal amplitude and in phase.
A distribution circuit for distributing to two output terminals, a dual-gate field effect transistor, and a quarter-wave strip line having an open end at a first output terminal of the distribution circuit.
A first coupler consisting of a circuit connected in sequence, the second output terminal of the distribution circuit being a second amplifier and a short circuited terminal 4
A second coupler composed of a strip line of one-half wavelength is sequentially connected, and the output signals of the first coupler and the second coupler are input to a synthesizing circuit for synthesizing in equal amplitude and in phase. Distortion compensation circuit characterized by being connected. 4. The first and second input signals are of equal amplitude and in phase.
A distribution circuit that distributes to the two output terminals of, and a first output terminal of the distribution circuit that has a first amplifier and an open end.
A first amplifier composed of a quarter-wave strip line is sequentially connected, and a second output terminal of the distribution circuit has a second amplifier having a configuration in which the first amplifier is connected in a plurality of stages.
A first attenuator and a quarter wavelength strip with a shorted end.
A second coupler composed of a line is sequentially connected, and the output signals of the first coupler and the second coupler are connected so as to be input to a combining circuit for combining the same amplitude and the same phase. Distortion compensation circuit. 5. The first input signal with an appropriate amplitude ratio and in-phase
And a second output terminal for distributing to a second output terminal, and a first output terminal of the distribution circuit for a first amplifier, a first attenuator, and a quarter wavelength having an open end. Strip line
A first coupler sequentially connecting consisting to the second output terminal of the distribution circuit, 4 minutes with a second amplifier, a short-circuit end
Second coupler consisting of a strip line of 1 wavelength is sequentially connected, and is connected so as to input the output signals of the first coupler and the second coupler to a combining circuit for combining in equal amplitude and in phase. Distortion compensation circuit characterized by having done.