JP2012205018A - High output power amplifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high output power amplifier that can output a high output signal by amplifying quarter divided signals of an input signal and combining all the divided signals, and can implement a downsized entire circuit constituting the high output power amplifier.SOLUTION: A high output power amplifier 10 comprises one four-way combination power amplifier circuit 11. The four-way combination power amplifier circuit 11 includes: hybrid circuits 22 and 26 for implementing two-way division/two-way combination with a phase difference of 90°; balance/unbalance circuits 23 (23a, 23b) and 25 (25a and 25b) for implementing two-way division/two-way combination with a phase difference of 180°; and power amplifiers 24 (24a-24d).

Description

  The present invention relates to a high output power amplifier mainly used in a mobile communication device such as a mobile phone. In particular, the present invention relates to a high output power amplifier that outputs a high frequency signal as an input signal and outputs a signal of several 10 to 100 W class by operating a plurality of amplifiers in parallel.

  Conventionally, a high-output power amplifier using a hybrid circuit is known (for example, Patent Document 1). FIG. 7 is a diagram showing a conventional high output power amplifier 900 using a hybrid circuit. As shown in FIG. 7, in the conventional high output power amplifier 900, the input terminals of the power amplifiers (amplifiers) 902 and 903 having the same performance are connected to the distribution terminals (output terminals) of the hybrid circuit 904, respectively. The output ends of the power amplifiers (amplifiers) 902 and 903 are connected to the combining terminal (input terminal) of the hybrid circuit 905, and the nonlinear distortion compensator 901 is connected to the input terminal of the hybrid circuit 904. It has become.

  A conventional high output power amplifier 910 using a Wilkinson distributor as shown in FIG. 8 is also known. As shown in FIG. 8, the conventional high-output power amplifier 910 using the Wilkinson type divider 910 has power amplifiers (amplifiers) 912 and 913 having the same performance as the output terminals of the Wilkinson divider 914, respectively. And the output ends of the power amplifiers (amplifiers) 912 and 913 are respectively connected to the input ends of the Wilkinson distributor 915. Here, R is an absorption resistance.

Japanese Utility Model Publication No. 5-28112

  In the conventional high output power amplifier 900 using the hybrid circuit described above, the impedance of the input / output terminals of the hybrid circuits 904 and 905 is generally 50Ω. In addition, in the amplifying elements (FETs) used in the power amplifiers (amplifiers) 902 and 903, the input / output impedance for obtaining the maximum gain from the amplifying elements (FETs) is generally in the range of several to several tens of ohms. Many. Therefore, in the high output power amplifier 900, in order to obtain the maximum gain of the power amplifiers (amplifiers) 902 and 903, the input / output matching of the amplifier element (FET) needs to be in the range of several to several tens of ohms. For example, in order to connect the hybrid circuit 904 and the power amplifier (amplifier) 902, it is necessary to provide an impedance conversion circuit between the hybrid circuit 904 and the power amplifier 902. Similarly, impedance conversion circuits are also provided between the hybrid circuit 904 and the power amplifier (amplifier) 903, between the hybrid circuit 905 and the power amplifier (amplifier) 902, and between the hybrid circuit 905 and the power amplifier (amplifier) 903. It was necessary to install. As the impedance difference between the impedance conversion circuits increases as the impedance difference increases, the space size of the impedance conversion circuit increases. Therefore, by providing a large number of impedance conversion circuits, the overall size of the high-output power amplifier 900 is enlarged. There was a problem that.

  Further, in the conventional high-output power amplifier 910 using the Wilkinson divider described above, for example, when high output power of several tens of watts or more is achieved, the power withstand voltage of the absorption resistance R of the Wilkinson dividers 914 and 915 is exceeded. As a result, there is a problem that the absorption resistor R is destroyed. Further, the impedance of the input / output terminals of the Wilkinson dividers 914 and 915 is generally 50Ω, and an impedance conversion circuit having a large space size is provided as in the case of the conventional high output power amplifier 900 using the hybrid circuit described above. There is also a problem that the size of the entire circuit of the high output power amplifier 910 is enlarged.

  Therefore, the present invention has been made to solve the above-described problems. After amplifying each of the distribution signals obtained by dividing the input signal into four parts, the high output is obtained by synthesizing all these distribution signals. An object of the present invention is to provide a high output power amplifier capable of outputting a signal and capable of reducing the size of the entire circuit constituting the high output power amplifier.

The following invention is provided to solve the above-mentioned conventional problems.
A high output power amplifier according to a first aspect of the present invention is a high output power amplifier that amplifies an input signal into a high output signal, the power distribution means for distributing the input signal into four distribution signals, and the power distribution 4 combined type power amplifier circuit comprising: an amplifier for amplifying each of the four distributed signals distributed by the means; and a power combining unit for combining the four distributed signals amplified by the amplifier into one combined signal The power distribution means includes one first distribution means for distributing one first input signal to two first distribution signals with a phase difference of 90 °, and one phase difference between one second input signal. Two second distribution means for distributing the two first distribution signals at 180 ° to each of the two second distribution means, the two first distribution signals distributed by the first distribution means. The second input signal of The input signal, which is one of the first input signals, is distributed to the four distribution signals, which are the second distribution signals, and the power combining means is configured to phase-differ the two third input signals. Two first synthesis means for synthesizing one first synthesized signal at 180 ° and one second synthesis means for synthesizing two fourth input signals into one second synthesized signal with a phase difference of 90 °, The distribution of four third input signals by inputting the two first synthesized signals respectively synthesized by the two first synthesizing means as the fourth input signals of the second synthesizing means. A signal is synthesized with the synthesized signal which is one second synthesized signal.

  The high output power amplifier according to the second aspect of the present invention is the high output power amplifier according to the first aspect of the present invention, wherein the second distributing means and the first combining means are balanced-unbalanced converters. The balanced / unbalanced converter serving as the second distribution means inputs an unbalanced signal and outputs a balanced signal, and the balanced / unbalanced converter serving as the first combining means inputs a balanced signal. And an unbalanced signal is output.

  A high output power amplifier according to a third aspect of the present invention is the high output power amplifier according to the second aspect of the present invention, wherein the balanced / unbalanced converter is a 180 ° balun. .

  The high output power amplifier according to the fourth aspect of the present invention is the same as the high output power amplifier according to the second aspect of the present invention, wherein the balanced / unbalanced converter includes a coaxial cable. It is a converter.

  A high output power amplifier according to a fifth aspect of the present invention is the high output power amplifier according to any one of the first to fourth aspects of the present invention, wherein the first distributing means and the second combining means are It is a 3 dB hybrid coupler.

  A high output power amplifier according to a sixth aspect of the present invention is the high output power amplifier according to any one of the first to fifth aspects of the present invention described above, connected to each of an input end and an output end of the amplifier. An oscillation prevention circuit is provided.

A high output power amplifier according to a seventh aspect of the present invention is the high output power amplifier according to any one of the first to sixth aspects of the present invention described above, wherein k is an integer value of k ≧ 1, and N is When N = 2 ^k , the four combined power amplifier circuits are arranged in parallel N, and the signals obtained by distributing the input signals into N signals are used as the input signals for the four combined power amplifier circuits. By further synthesizing the N synthesized signals synthesized for each of the four synthesized power amplifier circuits, each of the input signals is amplified to the (4 × N) synthesized high output signal.

  The high output power amplifier of the present invention divides the input signal, which is a high-frequency signal, into two parts with a phase difference of 90 °, and then distributes the two divided signals into two parts with a phase difference of 180 °, respectively. A number of 10 to 100 W obtained by synthesizing four amplified distributed signals by providing one 4-synthesized power amplifier circuit that amplifies and synthesizes the four distributed signals into one by a synthesis procedure opposite to the distribution procedure. Can output high output signal of class.

  Further, there is a balance as a means for distributing one signal into two signals with a phase difference of 180 ° (second distribution means) and a means for combining two signals into one signal with a phase difference of 180 ° (first combining means). By using an unbalanced converter, the impedance of the output terminal of the second distributing means and the impedance of the input terminal of the first synthesizing means can be reduced to 25Ω or less, so that an impedance conversion circuit having a large space size is not provided. The maximum gain of the amplifying element (FET) used in the power amplifier (amplifier) can be obtained. That is, even if the space size of the impedance conversion circuit provided between the second distributing means and the first combining hand and the power amplifier (amplifier) is reduced, the maximum number of amplifying elements (FETs) used in the power amplifier (amplifier) is reduced. Gain can be obtained. Therefore, the size of the entire circuit of the high output power amplifier can be reduced.

  In addition, by combining four input signals using a balanced / unbalanced converter and a hybrid circuit, even harmonic components generated by the power amplifier (amplifier), in particular, second harmonic components can be suppressed.

  In addition, by connecting an oscillation prevention circuit to each of the input and output terminals of the power amplifier (amplifier), it will not oscillate under any load conditions or environmental conditions (unconditionally stabilized) and perform stable operation. Can do.

1 is a block diagram of a high output power amplifier 10 according to a first embodiment of the present invention. It is a figure for demonstrating the coaxial type | mold balance-unbalance converter which has a coaxial cable. It is a block diagram of the high output power amplifier 110 concerning the modification of the 1st Embodiment of this invention. 3 is a diagram for explaining oscillation prevention circuits 27 and 28. FIG. It is a block diagram of the high output power amplifier 210 concerning the 2nd Embodiment of this invention. It is a figure which shows the suppression effect of a 2nd harmonic component. It is the figure which showed the conventional high output power amplifier 900 using a hybrid circuit. It is the figure which showed the conventional high output power amplifier 910 using the Wilkinson type | mold divider | distributor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the description in the present embodiment shows an example of the high-output power amplifier according to the present invention, and the present invention is not limited to this. The detailed configuration and the like of the high output power amplifier in the present embodiment can be changed as appropriate without departing from the spirit of the present invention.

  First, the high output power amplifier according to the first embodiment of the present invention will be described. FIG. 1 is a block diagram of a high output power amplifier 10 according to a first embodiment of the present invention. As shown in FIG. 1, the high-output power amplifier 10 according to the first embodiment of the present invention includes a single four-synthesis power amplifier circuit 11. In the high output power amplifier 10, a nonlinear distortion compensation circuit 21 is connected to the input side of the 4-synthesis power amplifier circuit 11 to reduce distortion components generated in the 4-synthesis power amplifier circuit 11.

  The four-composition power amplifier circuit 11 includes a power distribution circuit 12 that distributes an input signal into four distribution signals, a power amplifier 24 (24a to 24d), and four distributions amplified by the power amplifier 24 (24a to 24d). And a power combining circuit 13 for combining the signals. The power distribution circuit 12 includes a hybrid circuit 22 and a balanced / unbalanced circuit 23 (23a, 23b), and the power combining circuit 13 includes a hybrid circuit 26 and a balanced / unbalanced circuit 25 (25a and 25b). Yes.

  The hybrid circuit 22 is a distribution circuit that receives the signal W1 and distributes it to the signal W21 and the signal W22. The phase difference between the distributed signal W21 and the signal W22 is 90 °, and the output power of the signal W21 and the signal W22 is the power obtained by equally distributing the signal W1. The hybrid circuit 26 is a combining circuit that receives the signal W51 and the signal W52 and combines them with the signal W6. The phase difference between the input signal W51 and the signal W52 is synthesized at 90 °. As the hybrid circuits 22 and 26, it is preferable to use a 3 dB hybrid coupler.

  The balanced / unbalanced circuits 23a and 23b are distribution circuits that receive the signal W21 and the signal W22 and distribute them to the signal W31 and the signal W32, and the signal W33 and the signal W34, respectively. The phase difference between the distributed signal W31 and the signal W32 and the phase difference between the distributed signal W33 and the signal W34 are both 180 °, and the output power of the signal W31 and the signal W32 is the signal W21. And the output power of the signal W33 and the signal W34 is the power obtained by equally distributing the signal W22. In addition, the input signal W21 and the signal W22 are unbalanced signals, and the distributed signal W31 and the signal W32, and the signals W33 and W34 are balanced signals.

  The balanced / unbalanced circuits 25a and 25b are combining circuits that receive the signal W41 and the signal W42, and the signal W43 and the signal W44, respectively, and synthesize them into the signal W51 and the signal W52, respectively. The input signals W41 and W42 are combined with a phase difference of 180 °, and the signals W43 and W44 are combined with a phase difference of 180 °. Further, the input signal W41 and the signal W42, and the signal W43 and the signal W44 are balanced signals, and the synthesized signal W51 and the signal W52 are unbalanced signals.

  As the balanced / unbalanced circuits 23a, 23b, 25a and 25b, it is preferable to use 180 ° baluns. Further, as shown in FIG. 2, a coaxial balanced / unbalanced converter using the coaxial cable 31 as an unbalanced type and the two signal lines 32 and 33 as a balanced type is used as balanced unbalanced circuits 23a, 23b, 25a. And 25b are also preferably used.

  Further, in the balanced / unbalanced circuits 23a, 23b, 25a and 25b, it is preferable that the impedance of the input / output terminal on the unbalanced side is 50Ω and the impedance of the input / output terminal on the balanced side is 25Ω or less. That is, the impedance of the input terminals of the balanced / unbalanced circuits 23a and 23b and the impedance of the output terminals of the balanced / unbalanced circuits 25a and 25b are 50Ω, the impedance of the output terminals of the balanced / unbalanced circuits 23a and 23b, It is preferable that the impedances of the input terminals of the balanced circuits 25a and 25b be 25Ω or less (for example, 25Ω, 12.5Ω). In particular, it is preferable to set the impedance of the output terminal on the balanced side to 25Ω.

  Each of the power amplifiers 24a to 24d is a power amplifier having the same performance using an amplifying element (FET).

  Next, a distribution / amplification / combination procedure in the 4-composite power amplifier circuit 11 having the above-described configuration will be described. As shown in FIG. 1, first, an input signal W1 that is a high-frequency signal (for example, a microwave that is also used in a mobile phone) is input by the hybrid circuit 22 and distributed to the signal W21 and the signal W22 with a phase difference of 90 °. When a 3 dB hybrid coupler is used as the hybrid circuit 22, the impedance of the input / output terminal of the 3 dB hybrid coupler is 50Ω, and the microstrip line used as the transmission path of the input signal W 1 is also 50Ω, so it is necessary to provide an impedance conversion circuit. This eliminates the space size of the impedance conversion circuit.

  Thereafter, the signal W21 output from the hybrid circuit 22 is input to the balanced / unbalanced circuit 23a and distributed to the signals W31 and W32 with a phase difference of 180 °. Further, the signal W22 output from the hybrid circuit 22 is input to the balanced / unbalanced circuit 23b and distributed to the signals W33 and W34 with a phase difference of 180 °. By setting the impedance of the input terminals of the balanced / unbalanced circuits 23a and 23b to 50Ω and the impedance of the output terminals of the balanced / unbalanced circuits 23a and 23b to 25Ω or less, the impedance of the output terminals of the balanced / unbalanced circuits 23a and 23b and the amplifying element The difference from the input / output impedance of the (FET) (the input / output impedance range of several to several tens of ohms at which the maximum gain is obtained) is reduced, and only a small impedance conversion circuit is required. That is, the space size of the impedance conversion circuit provided between the balanced / unbalanced circuits 23 (23a, 23b) and 25 (25a and 25b) and the power amplifier 24 (24a to 24d) can be reduced.

  Thereafter, the power amplifiers 24a to 24d input the signal W31 and the signal W32 output from the balanced / unbalanced circuit 23a and the signal W33 and the signal W34 output from the balanced / unbalanced circuit 23b, respectively, to a desired output power. It amplifies and outputs as signal W41, signal W42, signal W43, and signal W44, respectively.

  Thereafter, the signal W41 and the signal W42 output from the power amplifiers 24a and 24b are input to the balanced / unbalanced circuit 25a, synthesized with a phase difference of 180 ° opposite to that of the balanced / unbalanced circuit 23a, and output as a signal W51. The signals W43 and W44 output from 24c and 24d are input to the balanced / unbalanced circuit 25b and synthesized with a phase difference of 180 ° opposite to that of the balanced / unbalanced circuit 23b and output as a signal W52.

  Thereafter, the signal W51 output from the balanced / unbalanced circuit 25a and the signal W52 output from the balanced / unbalanced circuit 25b are input by the hybrid circuit 26 and synthesized with a phase difference of 90 ° opposite to that of the hybrid circuit 22, A high output signal of ˜100 W class is output as the signal W6.

  Through the above-described distribution / amplification / synthesis procedure, the 4-synthesis power amplifier circuit 11 synthesizes four signals (W41, W42, W43, and W44) amplified to a desired output power by the power amplifier 24 (24a to 24d). Thus, an output power about four times the output power of the power amplifier 24 can be obtained. That is, the high-output power amplifier 10 according to the first embodiment of the present invention including one 4-synthesis type power amplifier circuit 11 is approximately four times the output power amplified by the power amplifier 24 (24a to 24d). Output power can be obtained.

  Further, the four-composition power amplifier circuit 11 uses the hybrid circuits 22 and 26 and the balanced / unbalanced circuits 23 (23a, 23b) and 25 (25a and 25b) to distribute and amplify the input signal into four parts, Then, by combining four, even harmonic components generated by the power amplifier 24 (24a to 24d), in particular, second harmonic components can be suppressed.

Next, the reason why even harmonic components can be suppressed will be described below.
Assuming that the power amplifiers 24a to 24d are class AB or class B amplifiers, the amplified output drain current Id is generally expressed by the following relational expression (1) when Fourier series expansion is performed.

  For example, in the case of the signal W41 amplified by the power amplifier 24a and the signal W42 amplified by the power amplifier 24b after being divided into two by the balanced / unbalanced circuit 23a with a phase difference of 180 °, the signal W41 is expressed by the relational expression (1). In the signal W42, “ωτ” in the relational expression (1) is replaced with “ωτ + π”. That is, it is represented by the following relational expression (2).

  Therefore, the signal W41 and the signal W42 have a relationship in which the odd-order term (fundamental wave component) is inverted. In the balanced / unbalanced circuit 25a, the amplified signal W41 and the signal W42 are combined at a phase difference of 180 ° opposite to that of the balanced / unbalanced circuit 23a, so that the even-order terms (even harmonic components) cancel each other, and the fundamental component Only the signal W51 synthesized twice is output. Similarly, in the balanced / unbalanced circuit 25b and the hybrid circuit 26, two are combined. As a result, the four-composition power amplifier circuit 11 outputs a signal W6 in which only the fundamental wave component is synthesized four times and the output is increased. Moreover, even harmonic components are canceled and suppressed by being synthesized by the balanced / unbalanced circuit 25a, balanced / unbalanced circuit 25b, and hybrid circuit 26.

  From the above, the high-output power amplifier 10 according to the first embodiment of the present invention having one 4-composite power amplifier circuit 11 outputs a high-output signal obtained by synthesizing four amplified distribution signals. And even harmonic components can be suppressed. Even if the space size of the impedance conversion circuit is reduced, the maximum gain of the amplifying element (FET) used in the power amplifier 24 (24a to 24d) can be obtained. Therefore, the size of the entire circuit of the high output power amplifier 10 can be reduced.

  Next, a high output power amplifier according to a modification of the first embodiment of the present invention will be described. FIG. 3 is a block diagram of a high-output power amplifier 110 according to a modification of the first embodiment of the present invention. Note that the description of the high-output power amplifier 110 shown in FIG. 3 will be described with respect to the difference from the high-output power amplifier 10 shown in FIG. 1, and the circuit having the same configuration as that of the high-output power amplifier 10 shown in FIG. Will not be described.

  As shown in FIG. 3, the difference between the four-composite power amplifier circuit 120 of the high-output power amplifier 110 and the four-composite power amplifier circuit 11 of the high-output power amplifier 10 shown in FIG. The oscillation prevention circuits 27 (27a to 27d) and 28 (28a to 28d) are connected to the input and output terminals of (24a to 24d), respectively.

  The oscillation prevention circuits 27 (27a to 27d) and 28 (28a to 28d) are circuits for performing stable operation while suppressing oscillation that is a problem in increasing the output of each power amplifier 24 (24a to 24d). In order to connect to a bias circuit for supplying a bias to an amplifying element (FET), a DC cut that does not leak a DC bias to a high frequency line, a matching circuit for obtaining a maximum gain from the amplifying element (FET), and a balanced / unbalanced circuit An impedance conversion circuit and a stabilization element are included.

  The oscillation prevention circuit 27 (27a to 27d) has, as an example of a basic configuration circuit, a configuration in which a bias circuit 52 and a matching circuit 54 are connected to the input side of an amplification element (FET) 51 used in the power amplifier 24 (see FIG. 4). The oscillation prevention circuit 28 (28a to 28d) has a configuration in which a bias circuit 53 and a matching circuit 55 are connected to the output side of the amplification element (FET) 51 as a basic configuration circuit (see FIG. 4).

  Further, in order to prevent signal loss due to leakage of high-frequency signals into the bias circuits 52 and 53, means for increasing the impedance of the bias port in the desired frequency band are provided on the lines 61 and 62. As a means for increasing the impedance of the bias port, a method of narrowing the line width of the lines 61 and 62, a method of adding resistance to the series, a method of cutting off a desired frequency using a filter circuit (implemented by L and C), or A method combining the above-described plurality of methods is used.

  The high-output power amplifier 110 according to the modification of the first embodiment of the present invention having the above-described configuration includes the oscillation prevention circuit 27 (27a to 27d) at the input end and the output end of each power amplifier 24 (24a to 24d). And 28 (28a to 28d) are connected to each other, so that stable operation can be performed without oscillation (unconditionally stabilized) under any load conditions, environmental conditions, and the like. .

  Similarly to the 4-composite power amplifier circuit 11, the 4-composite power amplifier circuit 120 of the high-output power amplifier 110 includes hybrid circuits 22 and 26 and balanced / unbalanced circuits 23 (23a, 23b) and 25 (25a and 25b) and the power amplifier 24 (24a to 24d), the high output power amplifier 110 can obtain the same effect as the high output power amplifier 10 shown in FIG.

  Next, a high output power amplifier according to a second embodiment of the present invention will be described. FIG. 5 is a block diagram of a high-output power amplifier 210 according to the second embodiment of the present invention. Note that the description of the high output power amplifier 210 shown in FIG. 5 will be described with respect to the difference from the high output power amplifier 10 shown in FIG. 1, and the circuit having the same configuration as the high output power amplifier 10 shown in FIG. Will not be described.

The high-output power amplifier 10 according to the first embodiment of the present invention shown in FIG. 1 is provided with one 4-synthesis power amplifier circuit 11, whereas the second embodiment of the present invention shown in FIG. In the high-output power amplifier 210 according to the embodiment, N (four in FIG. 5) N four-composite power amplifier circuits 11 are arranged in parallel, and an input signal WI input to the high-output power amplifier 210 is N. Hybrid circuit 222 for distributing N signals W1n (N ≧ n ≧ 1) input to four 4-synthetic power amplifier circuits 11, and signal W6n (N ≧ N) output from N four-composite power amplifier circuits 11 The hybrid circuit 223 is provided that outputs N as a result of N synthesis of n ≧ 1). Note that a 3 dB hybrid coupler is preferably used as the hybrid circuits 222 and 223. N is N = ^2k , and k is an integer value of k ≧ 1.

Further, FIG. 5 shows the case of N = 2 (k = 1), but in the case of N = 2 ^k (k ≧ 2), the case of N = 2 by combining 2k 3 dB hybrid couplers. The circuit corresponding to the hybrid circuit 222 is configured to distribute the input signal WI to N signals W1n input to the N four-composite power amplifier circuits 11, and further to the hybrid circuit 223 when N = 2. The signal W6n output from the N four-combining power amplifier circuits 11 is N-synthesized and output as WO. In FIG. 5, N four-composite power amplifier circuits 11 are arranged in parallel, but N four-composite power amplifier circuits 120 may be arranged in parallel.

  The high output power amplifier 210 according to the second embodiment of the present invention having the above-described configuration can obtain an output power that is approximately N times the output power amplified by the four-synthesis power amplifier circuit 11. That is, it is possible to obtain an output power that is approximately (4 × N) times the output power amplified by the power amplifier 24 that constitutes the four-synthesis power amplifier circuit 11. Further, by providing the four-composite power amplifier circuit 120 instead of the four-composite power amplifier circuit 11, it is possible to perform stable operation without oscillation (unconditionally stabilized) under any load conditions, environmental conditions, and the like. it can.

(Example)
Next, examples of the present invention will be described, but the present invention is not limited to these examples.

  The high output power amplifiers of Example 1 and Comparative Example 1 were prepared, and the suppression effect of the second harmonic component was measured. The high-output power amplifier according to the first embodiment is a circuit having the configuration shown in FIG. 3, using 3 dB hybrid couplers as the hybrid circuits 22 and 26, and balanced / unbalanced circuits 23 (23 a, 23 b) and 25 (25 a and 25 b). ) As a circuit using a 180 ° balun. The impedance of the input / output end of the 3 dB hybrid coupler is 50Ω, and the microstrip line used as the transmission path for the input signal is also 50Ω. The impedance of the input / output terminal on the unbalanced side of the 180 ° balun is 50Ω, and the impedance of the input / output terminal on the balanced side is 25Ω. The high output power amplifier of Comparative Example 1 is a circuit using a 3 dB hybrid coupler instead of the 180 ° balun in the high output power amplifier of Example 1 described above.

  As the suppression effect of the second harmonic component, the amount of suppression of the second harmonic component with respect to the output power of the fundamental wave component was measured in the high output power amplifiers of Example 1 and Comparative Example 1. The measurement results are shown in the graph of FIG. In FIG. 6, the horizontal axis represents output power (unit: dBm), and the vertical axis represents the suppression amount (unit: dBc) of the second harmonic component with respect to the output power of the fundamental wave. The solid line shows the result of Example 1, and the wavy line shows the result of Comparative Example 1.

  From the result of FIG. 6, it was found that the amount of suppression of the second harmonic component at the same output power is smaller in the high output power amplifier of Example 1 than in the high output power amplifier of Comparative Example 1. That is, it was found that the high output power amplifier of Example 1 had a second harmonic component suppression effect than the high output power amplifier of Comparative Example 1. In particular, when the output power is in the range of 40 to 48 dBm, it has been found that there is an improvement effect of 10 dBc or more.

DESCRIPTION OF SYMBOLS 10,110,210: High output power amplifier 11,120: 4 synthetic | combination type power amplifier circuit 12: Power distribution circuit 13: Power synthesis circuit 21: Nonlinear distortion compensation circuit 22,26,222,223: Hybrid circuit 23,23a, 23b, 25, 25a, 25b: Balance / unbalance circuit 24, 24a, 24b, 24c, 24d: Power amplifier 27, 27a, 27b, 27c, 27d, 28, 28a, 28b, 28c, 28d: Oscillation prevention circuit

Claims (7)

A high output power amplifier that amplifies an input signal into a high output signal,
Power distribution means for distributing the input signal into four distribution signals, amplifiers for amplifying the four distribution signals distributed by the power distribution means, and four distribution signals amplified by the amplifier as one One power combining circuit including a power combining means for combining with a combined signal,
The power distribution means includes
One first distribution means for distributing one first input signal to two first distribution signals with a phase difference of 90 °, and one second input signal to two second distribution signals with a phase difference of 180 ° Two second distribution means,
The two input first distribution signals distributed by the first distribution means are input as the second input signals of the two second distribution means, respectively, so that the input that is one first input signal Distributing the signal to the four distribution signals which are the second distribution signals;
The power combining means includes
Two first synthesis means for synthesizing two third input signals into one first synthesized signal with a phase difference of 180 °, and two fourth input signals into one second synthesized signal with a phase difference of 90 °. One second synthesizing means,
By inputting the two first synthesized signals respectively synthesized by the two first synthesizing means as the fourth input signals of the second synthesizing means, the distribution signals which are the four third input signals are obtained. A high-output power amplifier, characterized by being combined with the combined signal that is one second combined signal. The second distributing means and the first combining means are balanced-unbalanced converters;
The balanced / unbalanced converter serving as the second distributing means inputs an unbalanced signal and outputs a balanced signal;
2. The high output power amplifier according to claim 1, wherein the balanced / unbalanced converter serving as the first combining means inputs a balanced signal and outputs an unbalanced signal.   The high output power amplifier according to claim 2, wherein the balance-unbalance converter is a 180 ° balun.   3. The high output power amplifier according to claim 2, wherein the balanced / unbalanced converter is a coaxial balanced / unbalanced converter having a coaxial cable.   5. The high-output power amplifier according to claim 1, wherein the first distributing unit and the second combining unit are 3 dB hybrid couplers.   6. The high output power amplifier according to claim 1, further comprising an oscillation prevention circuit connected to each of an input end and an output end of the amplifier. When k is an integer value of k ≧ 1 and N is N = 2 ^k ,
N pieces of the four combined power amplifier circuits are arranged in parallel, and each signal obtained by distributing the input signal into N pieces is set as the input signal for each of the four combined power amplifier circuits. 7. The N output synthesized signals are further synthesized to amplify each of the input signals to the high output signal synthesized by (4 × N). The high output power amplifier described in 1.

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