JP2703796B2 - Nonlinear compensation circuit of high frequency amplifier - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-linear compensation circuit for correcting signal distortion caused by non-linearity of a high frequency amplifier.

[Conventional technology]

FIG. 3 shows a non-linear compensation circuit of a conventional high-frequency amplifier disclosed in, for example, Japanese Patent Application Laid-Open No. 52-5240. In the figure, reference numeral 1 denotes an input terminal, 2 denotes an output terminal, and 12 denotes an input signal. A distributor for distributing, 20 is a distortion generating amplifier, 21 and 22 are linear amplifiers, 25a to 25d are variable attenuators, and 30 is an output of the distortion generating amplifier 20 and the output of the linear amplifier 21 in opposite phases to synthesize a distortion. A distortion extracting combiner 31 to be extracted is a combiner that combines the distortion component extracted by the distortion extracting combiner 30 and the output of the linear amplifier 22 in opposite phases, and 40 is a high-frequency amplifier to be compensated.

Next, the operation will be described. The input signal input to the input terminal 1 is divided by the divider 12 into three. The first split output of splitter 12 is introduced to distortion generating amplifier 20. Amplifier for distortion generation
The signal amplified by 20 is derived including the distortion component,
The signal is introduced into the distortion extracting synthesizer 30 through the variable attenuator 25a. The second distributed output of the distributor 12 is introduced to the linear amplifier 21 via the variable attenuator 25b, amplified without including a distortion component, and introduced to the distortion extraction combiner 30. In the distortion extraction combiner 30, the output including the distortion component of the distortion generation amplifier 20 and the linear amplifier
By combining the output of the distortion generating amplifier 20 with the output that does not include the distortion component in the opposite phase, only the distortion component of the output of the distortion generating amplifier 20 is extracted, and the output is introduced to the combiner 31. Third of distributor 12
Is output by the linear amplifier 22 via the variable attenuator 25d without including a distortion component, and is introduced into the synthesizer 31. In the combiner 31, the output of the distortion extraction combiner 30 passing through the variable attenuator 25c and the output of the linear amplifier 22 are combined in opposite phases, and the combined output is input to the amplifier 40 to be compensated. The generated distortion component is canceled and amplified, and output to the output terminal 2. Here, the variable attenuator 25c is adjusted so that the distortion component generated in the amplifier 40 is canceled and the distortion component is not output to the output terminal 2.

[Problems to be solved by the invention]

Since the conventional nonlinear compensation circuit of the high-frequency amplifier is configured as described above, one linear amplifier must be provided in each of the remaining paths in order to correct the signal delay caused by the distortion generating amplifier. Two line meter amplifiers were required. In addition, there is a problem that the size of the circuit is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. One linear amplifier can correct the signal delay caused by the distortion generating amplifier and can reduce the circuit size. It is intended to obtain a compensation circuit.

[Means for solving the problem]

A non-linear compensation circuit for a high-frequency amplifier according to the present invention is connected to an input terminal and splits a high-frequency input signal into two.
A distortion generating amplifier for amplifying a first distributed output from the first distributor in a non-linear region; and a linear amplifier for amplifying a second distributed output from the first distributor in a linear region. An amplifier, a second divider for dividing the output of the linear amplifier into two, and an output of the distortion generating amplifier and a first distributed output from the second distributor to combine the output of the distortion generating amplifier. A first coupler for extracting a distortion component of an output; a second coupler for coupling a second distribution output of the second distributor and an output of the first coupler in opposite phases and sending the coupled output to an output terminal And a coupler.

[Action]

In the non-linear compensation circuit of the high-frequency amplifier according to the present invention, as described above, the input signal is divided into two, the first distributed output is introduced into the distortion generating amplifier, and the second distributed output is introduced into the linear amplifier. Later, the output is divided into two, and the output of the distortion generating amplifier and the first distributed output of the two splitter after the linear amplifier are combined in opposite phases to extract the distortion component of the distortion generating amplification. This is a circuit configuration in which the second distributed output of the two dividers after the linear amplifier is combined in the opposite phase, and since the distributor is arranged after the linear amplifier, one linear amplifier for distortion generation is used. The signal delay due to the amplifier is corrected, and the size of the circuit is reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a basic configuration of a nonlinear compensation circuit of a high-frequency amplifier according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an input terminal, 2 denotes an output terminal, 10a denotes a divider for dividing an input signal into two, Is a distortion generating amplifier that amplifies the first distributed output of the distributor 10a including a distortion component, 21 is a linear amplifier that amplifies the second distributed output of the distributor 10a without including a distortion component, and 25b is a linear amplifier. A variable attenuator for adjusting the input level so that the 21 operates in the linear region, a divider 10b for dividing the output of the linear amplifier 21 into two, and an output and a distortion 30 including the distortion component of the distortion generating amplifier 20 A combiner that combines the first distribution output of the distributor 10b containing no component with the opposite phase and extracts only the distortion component;
a is a variable subtractor for matching the power levels of the two-wave signal components input to the distortion extraction combiner 30, and 31 is a distortion component-only output of the distortion extractor 30 and a distributor that does not include the distortion component. Ten
A combiner that combines the second distributed output of b with the opposite phase, and a variable attenuator 25c that controls the ratio of the distortion component when the combiner 31 combines the signal component and the distortion component. This diagram corresponds to the circuit in FIG. 3 which does not include the amplifier 40 to be compensated.

Next, the operation of this basic configuration will be described. The signal input to the input terminal 1 is split into two by a splitter 10a, and the first split output is amplified by a distortion generating amplifier 20 including a distortion component. The second output of the distributor 10a is a variable attenuator 25b.
In, the linear amplifier 21 is attenuated to a power level operating in the linear region, and is amplified by the linear amplifier 21 without including a distortion component,
It is divided into two by the distributor 10b. The output of the distortion generating amplifier 20 is attenuated by the variable attenuator 25a so that the power level of the signal component is equal to the power level of the signal component of the first distribution output of the distributor 10b. Is introduced into the distortion extracting combiner 30 together with the first distributed output, and is combined in reverse phase to output only the distortion component. Distributor 10 without distortion components
The output of only the second distributed output of b and the distortion component of the distortion extraction combiner 30 that has passed through the variable attenuator 25 is combined by the combiner 31 in the opposite phase, and output to the output terminal 2. The variable attenuator 25c is used to adjust the power level of the distortion component with respect to the signal wave at the output terminal 2.

Although the principle of the present invention does not consider the correction of the signal delay by the variable attenuator, the dual gate FE
When a semiconductor element such as T is used as a variable attenuator, correction of signal delay by the variable attenuator may be considered. An embodiment at this time is shown in FIG.

In FIG. 1, the correction of the signal delay by the variable attenuator 25a is performed by the variable attenuator 25b.
The correction of the signal delay by 5c was not performed. However, by inserting the variable attenuator 25e between the distributor 10b and the combiner 31 as shown in FIG. 2, the signal delay can be corrected by the variable attenuator 25c.

Note that a variable gain amplifier may be used instead of the variable attenuator.

In the above embodiment, the one used in the RF unit is shown.
It may be used in a unit, and the same effects as in the above embodiment can be obtained.

〔The invention's effect〕

As described above, according to the non-linear compensation circuit of the high-frequency amplifier according to the present invention, the first distributor connected to the input terminal for dividing the high-frequency input signal into two, and the first distributor from the first distributor. A distortion generating amplifier for amplifying a distributed output in a non-linear region, a linear amplifier for amplifying a second distributed output from the first distributor in a linear region, and a second distribution for dividing the output of the linear amplifier into two A first combiner that combines an output of the distortion generating amplifier and a first distributed output from the second distributor to extract a distortion component of an output of the distortion generating amplifier; The second split output of the second splitter and the output of the first splitter are coupled in opposite phases, and the second output is sent to the output end.
, The difference between the signal delay amounts in the respective signal paths from the input terminal to the output terminal can be reduced, only one linear amplifier is required, and the nonlinear compensation circuit of the high-frequency amplifier is compact. There is an effect that can be made.

[Brief description of the drawings]

FIG. 1 is a block diagram of a non-linear compensation circuit of a high-frequency amplifier according to one embodiment of the present invention, FIG. 2 is a block diagram of a circuit showing another embodiment of the present invention, and FIG. It is a block diagram of a circuit. In the figure, 1 is an input terminal, 2 is an output terminal, 10a and 10b are first and second distributors, 20 is a distortion generation amplifier, 21 is a linear amplifier, and 30 is a distortion extraction combiner (first coupling). , 31 are synthesizers (second combiners). In the drawings, the same reference numerals indicate the same or corresponding parts.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Nao Takagi 5-1-1, Ofuna, Kamakura City, Kanagawa Prefecture Inside the Information and Electronics Research Lab., Mitsubishi Electric Corporation (72) Inventor Shuji Urasaki 5-1-1, Ofuna, Kamakura City, Kanagawa Prefecture No. 1 Inside the Information and Electronics Research Laboratories of Mitsubishi Electric Corporation (72) Katsuhisa Uno 1-6-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Masahiro Ueyama 1-1-1, Uchisaiwaicho, Chiyoda-ku, Tokyo No. 6 Nippon Telegraph and Telephone Corporation (56) References JP-A-1-123510 (JP, A) JP-A-52-5240 (JP, A) JP-A-60-241305 (JP, A)

Claims (1)

(57) [Claims] 1. A non-linear compensation circuit for a high-frequency amplifier, comprising: a first divider connected to an input terminal for dividing a high-frequency input signal into two, and a first distribution output from the first divider in a non-linear region. An amplifier for generating distortion to be amplified, a linear amplifier for amplifying a second distributed output from the first distributor in a linear region, a second distributor for dividing the output of the linear amplifier into two, A first combiner that combines an output of the amplifier for use with a first distributed output from the second distributor to extract a distortion component of an output of the amplifier for distortion generation; 2. A non-linear compensation circuit for a high-frequency amplifier, comprising: a second coupler that couples the output of the second coupler and the output of the first coupler in opposite phases to each other and sends the output to an output terminal.