Synthesis circuit

Abstract

To provide a synthesis circuit that monitors power absorbed by a terminating resistor or isolation resistor, controls the amplitude and phase of input power, minimizes the absorbed power, and reduces synthesis loss.SOLUTION: A synthesis circuit is provided with a variable ATT 11a, a phase shifter 12a, and an amplifier 13a before an input port P1 of a hybrid coupler 10, and is provided with a variable ATT 11b, a phase shifter 12b, and an amplifier 13b before an input port P2, and is provided with a coupler 15 at a terminal port P3 connected to a terminator 16 of the hybrid coupler 10, and detects the power branched by the coupler 15 by a detection circuit 17, and controls the variable ATTs 11a, 11b and the phase shifters 12a, 12b by the control circuit 19 such that the detected power is minimized.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a combining circuit for combining power, and more particularly to a combining circuit for improving combining efficiency. [Background technology]

[0002] [Prior Art] A power amplifier is a device that amplifies an input signal to a high power output. A power amplifier has an upper limit on the amount of power it can output, and when power greater than this upper limit is required, the outputs of a plurality of power amplifiers are combined to obtain the desired power.

[0003] Combiners are used to combine power, and there are hybrid coupler and Wilkinson type combiners. When the input signals are combined ideally, no loss occurs during the combining process, and all input signals are combined and output from the output terminal.

[0004] [Conventional hybrid coupler type combiner: Figure 3] A conventional hybrid coupler type combiner will be described with reference to Fig. 3. Fig. 3 is a schematic diagram of a conventional hybrid coupler type combiner. As shown in FIG. 3, a conventional hybrid coupler type combiner 10 receives input signals at ports 1 and 2, has a terminal at port 3, and serves as an output port at port 4. By setting the input signal to port 1 to have the same amplitude as the input signal to port 2 and a phase of -90° of the input signal to port 2, an ideal combined output can be obtained from port 4.

[0005] However, there is actually a transmission loss that occurs when the power passes through the combiner path, and a loss that occurs due to an imbalance in the phase and amplitude differences, and it is important for the combiner to minimize these combining losses. In particular, when combining multiple amplifiers, it is common to match the phase and gain between the devices to approach ideal conditions in actual operation. Therefore, a simulation of the combined loss due to the difference in amplitude and phase of the inputs will be described below.

[0006] [Simulation when there is a difference in amplitude: Figure 4] Fig. 4 shows the results of a simulation in which an amplitude difference is provided to the input. In particular, Fig. 4(a) shows the input power, the output voltage, the power absorbed by the terminator, and the combining efficiency, and Fig. 4(b) shows the relationship between the two input powers, the output power, and the termination power. The phase difference between input ports 1 and 2 in Figure 3 is set to an ideal condition of 90°, with port 1 remaining at 50 dBm (100 W) and port 2 gradually decreasing the power from 50 dBm (100 W) (50 dBm-X dB) to 0 dBm (X dB: 50 dB).

[0007] In Figure 4(a), the horizontal axis is the power reduction (XdB), the left vertical axis is power (W), and the right vertical axis is the combined efficiency (%). Curve a shows the total input power of ports 1 and 2, curve b shows the output power of port 4, curve c shows the power absorbed by the termination resistor of port 3, and curve d shows the combined efficiency (output power / total input power).

[0008] As the value of XdB increases, the power of port 2 becomes smaller than the power of port 1. When XdB is very small, the input power and the output power are close to each other, and the combined efficiency is close to 100%. At this time, the power absorbed by the termination resistor is also very small. However, as the value of XdB increases, the output power decreases compared to the input power, the combining efficiency deteriorates, and the power absorbed by the termination increases.

[0009] In addition, in Figure 4(b), the horizontal axis is the power reduction (XdB) and the vertical axis is the power (W), with curve e showing the total input power and curve f showing the total output power and the power absorbed by the termination resistor. From FIG. 4(b), it can be seen that curves e and f overlap, and the sum of the input power is equal to the sum of the output power and the power absorbed by the termination resistor. In other words, the combined loss caused by the imbalance in the amplitude of the input power is entirely absorbed by the termination resistor.

[0010] [Simulation when there is a phase difference: Figure 5] Fig. 5 shows the results of a simulation in which a phase difference is provided to the input. In particular, Fig. 5(a) shows the input power, the output voltage, the power absorbed by the terminator, and the combining efficiency, and Fig. 5(b) shows the relationship between the two input powers, the output power, and the termination power. The amplitude difference between input ports 1 and 2 in Figure 3 is set to zero, which is the ideal condition, port 1 remains at 50 dBm (100 W), port 2 also remains at 50 dBm (100 W), port 1 maintains the initial phase difference of -90° with respect to port 2, and the phase of port 2 is gradually shifted (0°-X°). -X° is the amount of phase shift.

[0011] In Figure 5(a), the horizontal axis represents the amount of phase shift (X°), the left vertical axis represents power (W), and the right vertical axis represents the combined efficiency (%). Curve a represents the total input power of ports 1 and 2, curve b represents the output power of port 4, curve c represents the power absorbed by the termination resistor of port 3, and curve d represents the combined efficiency (output power / total input power).

[0012] As the value of X° increases, the phase difference between port 1 and port 2 deviates from the ideal condition of 90°. When X° is small, the input power and the output power are close to each other, and the combined efficiency is close to 100%. At this time, the power absorbed by the termination resistor is also very small. However, as the value of X° increases, the output power decreases compared to the input power, the combining efficiency deteriorates, and the power absorbed by the termination increases.

[0013] In addition, in Figure 5(b), the horizontal axis represents the amount of phase shift (X°) and the vertical axis represents power (W), with curve e representing the total input power and curve f representing the total output power and power absorbed by the termination resistor. From FIG. 5(b), it can be seen that curves e and f overlap, and the sum of the input power is equal to the sum of the output power and the power absorbed by the termination resistor. In other words, the combined loss caused by the phase difference of the input power deviating from the ideal condition is entirely absorbed by the termination resistor. Therefore, from Figures 4 and 5, we can see that all losses that occur when the amplitude and phase of the input power deviate from ideal conditions are absorbed by the termination resistor.

[0014] [Conventional Wilkinson type combiner: Figure 6] A conventional Wilkinson type combiner will be described with reference to Fig. 6. Fig. 6 is a schematic diagram of a conventional Wilkinson type combiner. As shown in FIG. 6, the conventional Wilkinson combiner includes input ports 21a and 21b, 1 / 4λ lines 22a and 22b, an isolation resistor 24 connecting the input sides of the input ports 21a and 21b, and an output port 23 connecting the output sides of the 1 / 4λ lines 22a and 22b.

[0015] The impedance of the input ports 21a, 21b and the output port 23 is a typical 50Ω, the impedance of the 1 / 4λ lines 22a, 22b is 70.7Ω, and the impedance of the isolation resistor 24 is 100Ω. In the case of a Wilkinson type combiner, combining can be performed most efficiently when the amplitudes between the input ports are the same and the phase difference is 0°.

[0016] In the conventional Wilkinson combiner, when the amplitude and phase between the input ports deviate from the ideal conditions, combining losses occur as in the hybrid coupler combiner, and these losses are all absorbed by the isolation resistor 24 .

[0017] In this way, the Wilkinson combiner is ideally designed to operate so that all the combining loss is absorbed by the isolation resistor 24, but the route from the input port 21b through the isolation resistor 24 and the route from the input port 21b through the two 1 / 4λ lines 22b and 22a must be out of phase with each other by 180°. This is because each 1 / 4λ line has a phase delay of 90°.

[0018] [Related Technology] Related prior art includes JP 2012-151748 A, “Power amplifier circuit, and power amplifier circuit, transmitter, and communication device using the same” (Patent Document 1), JP 2016-004745 A, “High-frequency power supply” (Patent Document 2), JP 2006-345464 A, “High-frequency distribution circuit” (Patent Document 3), and JP 2013-172174 A, “Power amplifier and transmission system” (Patent Document 4).

[0019] Patent Document 1 discloses a power amplifier circuit having two input terminals, one output terminal, and a terminal to which a termination resistor is connected. Patent Document 2 discloses a high-frequency power supply having a hybrid circuit that has two input ports, one output port, and a port that is grounded via a resistor, with each port having a predetermined impedance.

[0020] Patent Document 3 shows a high-frequency distribution circuit having one input terminal, two output terminals, and a terminal to which a terminating resistor element is connected. Patent Document 4 discloses a 90° hybrid coupler having two input terminals, one output terminal, and a terminal connected to an absorbing resistor, and having a characteristic impedance of 25Ω. [Prior art documents] [Patent documents]

[0021] [Patent Document 1] JP 2012-151748 A [Patent Document 2] JP 2016-004745 A [Patent Document 3] JP 2006-345464 A [Patent Document 4] JP 2013-172174 A Summary of the Invention [Problem to be solved by the invention]

[0022] However, conventional combiners have a problem in that they cannot effectively improve the combined loss caused by the combined power flowing into the termination resistor or isolation resistor due to the imbalance in the amplitude and phase of the input power.

[0023] Incidentally, Patent Documents 1 to 4 do not disclose a configuration for reducing the combined loss by monitoring the power absorbed by a termination resistor or an isolation resistor and controlling the amplitude and phase of the input power.

[0024] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a combining circuit that monitors the power absorbed by a termination resistor or an isolation resistor, controls the amplitude and phase of the input power, and minimizes the absorbed power, thereby reducing the combining loss. [Means for solving the problem]

[0025] The present invention, which is intended to solve the problems of the above-mentioned conventional examples, is a combining circuit using a hybrid coupler, characterized in having: a first amplifier provided in front of a first input port of the hybrid coupler; a second amplifier provided in front of a second input port of the hybrid coupler; a first variable attenuator provided in front of the first amplifier for adjusting the amplitude; a first phase shifter for adjusting the phase; a second variable attenuator provided in front of the second amplifier for adjusting the amplitude; a second phase shifter for adjusting the phase; a first coupler provided at a termination port connected to a terminator of the hybrid coupler; a detection circuit for detecting power branched by the first coupler; and a control circuit for controlling the first variable attenuator, the second variable attenuator, the first phase shifter, and the second phase shifter so that the power detected by the detection circuit is minimized.

[0026] In the present invention, in the above synthesis circuit, the control circuit controls each of the controlled devices to perform detection. circuit It is characterized by repeatedly controlling each device by inputting the power obtained from the

[0027] The present invention relates to a Wilkinson type combining circuit, comprising a first line, a second line, an isolation resistor connecting the input side of the first line and the input side of the second line, and an output terminal connecting the output side of the first line and the output side of the second line, and further comprising a first amplifier provided on the input side of the first line, a first variable attenuator provided in front of the first amplifier for adjusting the amplitude, a first phase shifter for adjusting the phase, a second amplifier provided on the input side of the second line, and a second variable attenuator provided in front of the second amplifier for adjusting the amplitude. the first variable attenuator, a second phase shifter for adjusting the phase, a first coupler and a second coupler provided at both ends of an isolation resistor, a first phase adjustment line and a second phase adjustment line, a first detection circuit for detecting power branched by the first coupler, a second detection circuit for detecting power branched by the second coupler, and a control circuit for controlling the first variable attenuator, the second variable attenuator, the first phase shifter, and the second phase shifter so that the power detected by the first detection circuit and the second detection circuit is minimized.

[0028] In the above-mentioned synthesis circuit, the control circuit controls each of the controlled devices to perform the first detection circuit The power obtained from the first and second detection circuits is input to repeatedly control each device. Effect of the Invention

[0029] According to the present invention, a first variable attenuator for adjusting the amplitude, a first phase shifter for adjusting the phase, and a first amplifier are provided in front of a first input port of a hybrid coupler, a second variable attenuator for adjusting the amplitude, a second phase shifter for adjusting the phase, and a second amplifier are provided in front of a second input port of the hybrid coupler, a first coupler is provided at a termination port connected to a terminator of the hybrid coupler, and the power branched by the first coupler is detected by a detection circuit, and a combiner is configured in which the first variable attenuator, the second variable attenuator, the first phase shifter, and the second phase shifter are controlled by a control circuit so that the detected power is minimized, thereby having the effect of reducing the combined loss by minimizing the power flowing into the terminator.

[0030] According to the present invention, a first variable attenuator for adjusting the amplitude, a first phase shifter for adjusting the phase, and a first amplifier are provided on the input side of a first line, a second variable attenuator for adjusting the amplitude, a second phase shifter for adjusting the phase, and a second amplifier are provided on the input side of a second line, a first coupler and a second coupler, a first phase adjustment line and a second phase adjustment line are provided on both ends of an isolation resistor, the power branched by the first coupler is detected by a first detection circuit, the power branched by the second coupler is detected by a second detection circuit, and the first variable attenuator, the second variable attenuator, the first phase shifter, and the second phase shifter are controlled by a control circuit to form a combiner such that the power detected by the first detection circuit and the second detection circuit is minimized, thereby having the effect of reducing the combined loss by minimizing the power flowing into the isolation resistor. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a schematic diagram of a combining circuit using a hybrid coupler. [Diagram 2] FIG. 1 is a schematic diagram of a Wilkinson type combining circuit. [Diagram 3] FIG. 1 is a schematic diagram of a conventional hybrid coupler type combiner. [Figure 4] FIG. 13 is a diagram showing a simulation result when an amplitude difference is provided in the input. [Diagram 5]FIG. 13 is a diagram showing a simulation result when a phase difference is provided in the input. [Figure 6] FIG. 1 is a schematic diagram of a conventional Wilkinson type combiner. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. [Outline of the embodiment] A combining circuit according to an embodiment of the present invention (the present combining circuit) is a hybrid coupler-type combining circuit using a hybrid coupler, in which a first amplifier is provided in front of a first input port of the hybrid coupler, a second amplifier is provided in front of a second input port of the hybrid coupler, a first variable attenuator for adjusting the amplitude and a first phase shifter for adjusting the phase are provided in front of the first amplifier, a second variable attenuator for adjusting the amplitude and a second phase shifter for adjusting the phase are provided in front of the second amplifier, a first coupler is provided at a termination port connected to a terminator of the hybrid coupler, the power branched by the first coupler is detected by a detection circuit, and the first and second variable attenuators and the first and second phase shifters are controlled by a control circuit so that the detected power is minimized, and the combining loss can be reduced by minimizing the power flowing into the terminator.

[0033] Furthermore, another combiner circuit according to an embodiment of the present invention (another combiner circuit) is a Wilkinson type combiner circuit, comprising a first line, a second line, an isolation resistor connecting the input side of the first line and the input side of the second line, and an output terminal coupling the output side of the first line and the output side of the second line, a first amplifier is provided on the input side of the first line, a first variable attenuator for adjusting the amplitude and a first phase shifter for adjusting the phase are provided in front of the first amplifier, a second amplifier is provided on the input side of the second line, and a second variable attenuator for adjusting the amplitude and a first phase shifter are provided in front of the second amplifier. A variable attenuator and a second phase shifter for adjusting the phase are provided, a first coupler and a second coupler, and a first phase adjustment line and a second phase adjustment line are provided on both ends of an isolation resistor, the power branched by the first coupler is detected by a first detection circuit, the power branched by the second coupler is detected by a second detection circuit, and the first and second variable attenuators and the first and second phase shifters are controlled by a control circuit so that the power detected by the first and second detection circuits is minimized, and by minimizing the power flowing into the isolation resistor, the combined loss can be reduced.

[0034] [This synthesis circuit: Figure 1] This combining circuit will be described with reference to Figure 1. Figure 1 is a schematic diagram of a combining circuit using hybrid couplers. This combining circuit is a hybrid coupler type combining circuit, and as shown in FIG. 1, a variable attenuator (variable attenuator / variable ATT) 11a, a phase shifter 12a, and an amplifier 13a are connected to an input port P1 of a hybrid coupler 10, a variable attenuator (variable ATT) 11b, a phase shifter 12b, and an amplifier 13b are connected to an input port P2, an isolator 14, a coupler 15, and a terminator 16 are connected to a termination port P3, and a combined power is output from an output port P4.

[0035] The coupler 15 also branches the input power into two outputs, one of which is connected to a detection circuit 17 and the other to a termination 18 . The result of detection by the detection circuit 17 is input to the control circuit 19, which controls the variable ATTs 11a and 11b and the phase shifters 12a and 12b. Specific control in the control circuit 19 will be described later.

[0036] [Parts of this synthesis circuit] Each part of this synthesis circuit will now be described in detail. The amplifier 13a is a first amplifier provided in front of the input port P1 (first input port) of the hybrid coupler 10. Phase shifter 12a is a first phase shifter that is provided in the preceding stage of amplifier 13a and adjusts the phase. The variable ATT 11a is provided in front of the phase shifter 12a and is a first variable attenuator that adjusts the amplitude.

[0037] The amplifier 13b is a second amplifier provided in front of the input port P2 (second input port) of the hybrid coupler 10. Phase shifter 12b is a second phase shifter that is provided in the preceding stage of amplifier 13b and adjusts the phase. The variable ATT 11b is a second variable attenuator that is provided in front of the phase shifter 12b and adjusts the amplitude.

[0038] The isolator 14 is connected to the termination port P3 to prevent the return of power, but may be removed if it does not affect the characteristics of the hybrid coupler. The coupler 15 is provided between the isolator 14 and the terminator 16 , and is connected to the detection circuit 17 and the terminator 18 . The coupler 15 outputs the power input from the isolator 14 to the terminator 16, and also branches the input power and outputs it to the detection circuit 17. In the claims, it is referred to as a “first coupler” to avoid confusion with the hybrid coupler 10. The terminator 16 is a terminating resistor and is assumed to be 50Ω.

[0039] The detection circuit 17 detects the power branched off from the coupler 15 , and outputs the detected power value to the control circuit 19 . The control circuit 19 controls the variable ATTs 11a and 11b and the phase shifters 12a and 12b so that the power detected by the detection circuit 17 is minimized.

[0040] Specifically, the control circuit 19 controls the variable ATTs 11a and 11b to adjust the amplitude so that the amplitudes of input 1 and input 2 are the same, and controls the phase shifters 12a and 12b to adjust the phase difference so that input 1 is -90° relative to input 2.

[0041] Then, as a result of controlling the variable ATTs 11a, 11b and the phase shifters 12a, 12b, the control circuit 19 detects the power branched off from the coupler 15 in the detection circuit 17, and repeats the process of further controlling the variable ATTs 11a, 11b and the phase shifters 12a, 12b based on the detected power, thereby minimizing the power flowing into the terminator 16.

[0042] [Another synthesis circuit: Figure 2] Another combining circuit will be described with reference to Fig. 2. Fig. 2 is a schematic diagram of a Wilkinson type combining circuit. The other combining circuit is a Wilkinson-type combining circuit, which, as shown in FIG. 2, includes input ports (input terminals) 31a, 31b, 1 / 4λ lines 32a, 32b, an isolation resistor 34 connecting the input sides thereof, and an output port (output terminal) 33 connecting the output sides of the 1 / 4λ lines 32a, 32b.

[0043] Between the input port 31a and the 1 / 4λ line 32a, a variable ATT 35a, a phase shifter 36a, and an amplifier 37a are provided. In addition, a variable ATT 35b, a phase shifter 36b, and an amplifier 37b are provided between the input port 31b and the 1 / 4λ line 32b.

[0044] Furthermore, a first coupler 39a, a second coupler 39b, a phase adjustment line 38a, and a phase adjustment line 38b are provided on both ends of the isolation resistor 34. That is, from the top of FIG. 3, the phase adjustment line 38a, the first coupler 39a, the isolation resistor 34, the second coupler 39b, and the phase adjustment line 38b are connected in series in this order.

[0045] A detection circuit 41a and a termination 42a are connected to the first coupler 39a, and a detection circuit 41b and a termination 42b are connected to the second coupler 39b. Furthermore, the first detection circuits 41a and 41b are connected to a control circuit 43, and the control circuit 43 controls the variable ATTs 35a and 35b and the phase shifters 36a and 36b. Specific control by the control circuit 43 will be described later.

[0046] [Parts of another composite circuit] Each part of the alternative synthesis circuit will now be described in detail. The amplifier 37a is a first amplifier provided in front of the 1 / 4λ line 32a. Phase shifter 36a is provided in the preceding stage of amplifier 37a and is a first phase shifter that adjusts the phase. The variable ATT 35a is provided in front of the phase shifter 36a and is a first variable attenuator that adjusts the amplitude.

[0047] The amplifier 37b is a second amplifier provided in front of the 1 / 4λ line 32b. Phase shifter 36b is a second phase shifter that is provided in the preceding stage of amplifier 37b and adjusts the phase. The variable ATT 35b is a second variable attenuator that is provided in front of the phase shifter 36b and adjusts the amplitude.

[0048] The phase adjustment lines 38a and 38b are lines for adjusting the phase rotation that occurs in the couplers 39a and 39b. The phase adjustment will be described later. The couplers 39a and 39b are provided between the isolation resistor 34 and the phase adjustment lines 38a and 38b, and are connected to the detection circuits 41a and 41b and the terminations 42a and 42b.

[0049] The coupler 39a outputs the power input from the phase adjustment line 38a to the isolation resistor 34, and also branches the input power to output it to the detection circuit 41a. The coupler 39b outputs the power input from the phase adjustment line 38b to the isolation resistor 34, and also branches the input power and outputs it to the detection circuit 41b. The isolation resistor 34 is assumed to be 100 Ω.

[0050] The detection circuit 41 a detects the power branched off from the coupler 39 a and outputs the detected power value to the control circuit 43 . The detection circuit 41b detects the power branched off from the coupler 39b, and outputs the detected power value to the control circuit 43. The control circuit 43 controls the variable ATTs 35a and 35b and the phase shifters 36a and 36b so that the power detected by the detection circuits 41a and 41b is minimized.

[0051] Specifically, the control circuit 43 controls the variable ATTs 35a and 35b to adjust the amplitude so that the amplitude of input 1 from input port 31a and the amplitude of input 2 from input port 31b are the same, and controls the phase shifters 36a and 36b to adjust the phase difference between inputs 1 and 2 to 0°.

[0052] Then, as a result of controlling the variable ATTs 35a, 35b and the phase shifters 36a, 36b, the control circuit 43 detects the power branched off from the couplers 39a, 39b using the detection circuits 41a, 41b, and repeats the process of further controlling the variable ATTs 35a, 35b and the phase shifters 36a, 36b based on the detected power, thereby minimizing the power flowing into the isolation resistor 34.

[0053] As explained in the conventional Wilkinson-type combiner, a phase difference of 180° is required between the path that passes through isolation resistor 34 and the path that goes around the 1 / 4λ lines 32b, 32a. However, because couplers 39a, 39b are inserted before and after isolation resistor 34, one coupler shifts the phase by 90°, and two couplers delay the phase by 180°.

[0054] Therefore, phase adjustment lines 38a and 38b are inserted to set the phase of the path passing through isolation resistor 34 to 360°. Each phase adjustment line delays the phase by 90°, two phase adjustment lines delay the phase by 180°, and the two couplers together delay the phase by 360°. Since there is a phase delay of 180° in the path passing through the ¼λ lines 32b and 32a, there is a phase difference of 180° in the two paths. The phase adjustment in the phase adjustment lines 38a and 38b is set according to the phase circulation in the couplers 39a and 39b.

[0055] [Effects of the embodiment] According to this combining circuit, a hybrid coupler type combining circuit is provided with a variable ATT 11a, a phase shifter 12a, and an amplifier 13a in front of an input port P1 of a hybrid coupler 10, a variable ATT 11b, a phase shifter 12b, and an amplifier 13b in front of an input port P2, a coupler 15 is provided at a termination port P3 connected to a terminator 16 of the hybrid coupler 10, the power branched by the coupler 15 is detected by a detection circuit 17, and the variable ATTs 11a, 11b and the phase shifters 12a, 12b are controlled by a control circuit 19 so that the detected power is minimized, and the combined loss can be reduced by minimizing the power flowing into the terminator 16.

[0056] According to another combiner circuit, the combiner circuit is a Wilkinson type combiner circuit, and includes 1 / 4 λ lines 32a and 32b, an isolation resistor 34 connecting the input sides of the lines, and an output port 33 connecting the output sides of the 1 / 4 λ lines 32a and 32b. A variable ATT 35a, a phase shifter 36a, and an amplifier 37a are provided between the input port 31a and the 1 / 4 λ line 32a, and a variable ATT 35b, a phase shifter 36b, and an amplifier 37a are provided between the input port 31b and the 1 / 4 λ line 32b. In this embodiment, a phase shifter 37b is provided, couplers 39a, 39b and phase adjustment lines 38a, 38b are provided on both ends of the isolation resistor 34, and the power branched off by the couplers 39a, 39b is detected by detection circuits 41a, 41b. The variable ATTs 35a, 35b and the phase shifters 36a, 36b are controlled by a control circuit 43 so that the detected power is minimized. By minimizing the power flowing into the isolation resistor 34, it is possible to reduce the combined loss. [Industrial Applicability]

[0057] The present invention is suitable for a combining circuit that monitors the power absorbed in a termination resistor or isolation resistor and controls the amplitude and phase of the input power to minimize the absorbed power and reduce the combining loss. [Explanation of symbols]

[0058] 10... hybrid coupler, 11a, 11b, 35a, 35b... variable ATT, 12a, 12b, 36a, 36b... phase shifter, 13a, 13b, 37a, 37b... amplifier, 14... isolator, 15, 39a, 39b... coupler, 16... terminator, 17, 41a, 41b... detector circuit, 18, 42a, 42b... termination, 19, 43... control circuit, 21a, 21b, 31a, 31b... input port, 22a, 22b, 32a, 32b... 1 / 4 λ line, 23, 33... output port, 24, 34... isolation resistor, 38a, 38b... phase adjustment line

Claims

1. A combining circuit using a hybrid coupler, a first amplifier provided in front of a first input port of the hybrid coupler; a second amplifier provided in front of a second input port of the hybrid coupler; a first variable attenuator for adjusting an amplitude and a first phase shifter for adjusting a phase, the first variable attenuator being provided in a stage preceding the first amplifier; a second variable attenuator for adjusting an amplitude and a second phase shifter for adjusting a phase, the second variable attenuator being provided in a stage preceding the second amplifier; a first coupler provided at a termination port connected to a terminator of the hybrid coupler; a detection circuit that detects the power branched by the first coupler; a control circuit that controls the first variable attenuator, the second variable attenuator, the first phase shifter, and the second phase shifter so that the power detected by the detection circuit is minimized.

2. 2. The combining circuit according to claim 1, wherein the control circuit controls each of the controlled devices and inputs the power obtained from the detection circuit to repeat the control of each of the controlled devices.

3. A Wilkinson type combining circuit, a first line, a second line, an isolation resistor connecting an input side of the first line and an input side of the second line, and an output terminal coupling an output side of the first line and an output side of the second line, a first amplifier provided on an input side of the first line; a first variable attenuator for adjusting an amplitude and a first phase shifter for adjusting a phase, the first variable attenuator being provided in a stage preceding the first amplifier; a second amplifier provided on the input side of the second line; a second variable attenuator for adjusting an amplitude and a second phase shifter for adjusting a phase, the second variable attenuator being provided in a stage preceding the second amplifier; a first coupler and a second coupler provided at both ends of the isolation resistor, a first phase adjustment line and a second phase adjustment line; a first detection circuit that detects the power branched by the first coupler; a second detection circuit that detects the power branched by the second coupler; a control circuit that controls the first variable attenuator, the second variable attenuator, the first phase shifter, and the second phase shifter so that power detected by the first detection circuit and the second detection circuit is minimized.

4. The combining circuit according to claim 3, characterized in that the control circuit controls each of the controlled devices to input the power obtained from the first detection circuit and the second detection circuit, and repeats the control of each of the devices.

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