Power combiner

Abstract

To provide a line pattern capable of miniaturizing a circuit board.SOLUTION: A signal inputted to input port Pin1 passes through line 201 and is coupled in the shortest way with a signal inputted from input port Pin2, branched and passed through line 205a without meandering, and similarly, a signal inputted to input port Pin3 passes through line 203 and is coupled in the shortest way with a signal inputted from input port Pin2, branched to the other side and passed through line 205b without meandering. Lines extending from these two coupling portions through the line 215a and the line 235b, respectively, are provided.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to power combining of high frequency signals, and more particularly to a power combiner for the HF to SHF bands. [Background technology]

[0002] For example, when obtaining a high-power output from a transmitter, a method is used in which one input signal is divided into multiple signals, each of which is amplified by a medium-power or low-power amplifier, and then the resulting powers are combined (see, for example, Patent Document 1). This method has the advantage of reducing the burden on each amplifier and avoiding nonlinearity, particularly when obtaining high power using many solid-state amplifiers that use semiconductors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-236105 Summary of the Invention [Problem to be solved by the invention]

[0004] In power combining, which combines input and output ports using circuit patterns formed on a planar substrate, it is necessary to optimize the line length for phase alignment, especially when handling high-frequency signals with short wavelengths of the input signals.

[0005] When combining signals of the same frequency and phase amplified from the same signal source, phase matching is performed by optimizing the length of the line from the input port to the junction of the line pattern so that the signals from each amplifier are combined in the same phase within the combiner.

[0006] In order to combine multiple signals with short wavelengths and high frequencies that cannot be ignored (for example, 10 meters at 30 MHz, and 10 millimeters at 30 GHz) into a circuit pattern on a board (for example, on the order of several tens of centimeters), it is necessary to adjust the length of the lines made up of distributed constant circuits and align the phase of each signal at the point where the signals join.

[0007] For example, as shown in Figure 4, if the line length from port A to port D is different from the line length from port B to port D, out-of-phase signals will be combined at port D. As a result, the combined signals will cancel each other out, causing a phase mismatch and preventing the desired power combination.

[0008] Figure 5 shows a line pattern on a circuit board using conventional technology. As shown in Figure 5, the line pattern is configured so that port A on the left and port C on the right are symmetrical with respect to port D in the center, and the line from port B is designed to be detoured so that the line lengths are equal. This makes the line lengths from port A to port D, the line from port B to port D, and the line from port C to port D equal, and the three signals are combined at port D.

[0009] The line pattern of the prior art requires an area for detouring the line from the central port B to the output port D. This means that the distance from port B to port D in the direction indicated by the arrow in the figure is longer than when port B is coupled in a straight line, resulting in issues such as reduced design freedom and increased costs.

[0010] Furthermore, if the line is bent back and forth like a hairpin to increase the distance from port B to port D, there is a problem of interference between adjacent lines. In particular, when high-frequency currents flow, eddy currents inside the lines affect adjacent lines, causing undesirable effects on electrical characteristics.

[0011] This is because the section of the line from port B to port D that influences the other in the folded line is longer than the line from port A to port D and the line from port C to port D, and furthermore, the symmetry seen from port D is lost, making it difficult to obtain the desired power combining performance. [Means for solving the problem]

[0012] The power combiner of the present invention is a power combiner that receives outputs of a plurality of power amplifiers arranged in the longitudinal direction of a circuit board at approximately the same phase, and includes first, second, and third input sections arranged in the longitudinal direction of the circuit board corresponding to each power amplifier, a combining circuit that combines the powers input to each input section, and an output section that outputs the power combined by the combining circuit, and is configured so that the lengths of the lines connecting each input section and the output section are approximately equal, and the combining circuit includes a first line having a line connecting the first input section and the output section, a second line having a line connecting the third input section and the output section, and a third line that branches from the second input section arranged between the first input section and the third input section, and couples one end to the first line and the other to the second line, thereby having a line connecting the second input section and the output section.

[0013] A circuit board equipped with a power combiner of the present invention has multiple power amplifiers connected in the longitudinal direction of the board, each connected to an input section. When multiple power amplifiers are connected, the length of the board in the longitudinal direction increases in proportion to the number of power amplifiers. This makes it difficult to shorten the length of the board in the longitudinal direction.

[0014] However, the line pattern of the power combiner according to the present invention can adjust the line length by extending the lines in the longitudinal direction of the board, thereby shortening the length of the board in the direction perpendicular to the longitudinal direction of the board, thereby realizing the miniaturization of the entire circuit board.

[0015] In the above configuration, the third line has a configuration in which a line branching from the second input portion is coupled to the first and second lines at the shortest distance.

[0016] According to the above configuration, the lines are coupled to the first and second lines over the shortest distance without meandering, so that interference between adjacent lines can be avoided.

[0017] In the above configuration, the third line is configured such that one line coupled to the first line and the other line coupled to the second line are arranged in line symmetry.

[0018] According to the above configuration, by arranging one line and the other line in line symmetry, it is possible to equalize the characteristics of each line.

[0019] In the above configuration, the first input section and the third input section are arranged symmetrically with respect to a virtual line connecting the output section and the second input section arranged on the circuit board, the first line and the second line are arranged symmetrically with respect to the virtual line, and one line and the other line of the third line are arranged symmetrically with respect to the virtual line.

[0020] According to the above configuration, the input sections can be arranged at equal intervals around the output section, so that the line lengths from the input sections to the output sections can be designed to be equal, thereby making the phase characteristics equal.

[0021] In the above configuration, the third line has an impedance width that is approximately twice that of the first or second line.

[0022] According to the above configuration, the third line is configured with a width that provides approximately twice the impedance of the first or second line. Furthermore, the dynamic impedance at the coupling point of the first line is the value obtained by paralleling the impedances of the respective lines. Similarly, the impedance at the second coupling point is the value obtained by paralleling the impedances of the respective lines. Furthermore, impedance matching can be achieved by matching the impedances of the lines from the combining unit to the coupling point of the first line and the line from the combining unit to the coupling point of the second line with the dynamic impedance at the coupling point.

[0023] Here, the operating impedance at the junction of the output section is the value obtained by combining the impedances of the junction of the first line and the junction of the second line in parallel, and this power combiner operates when a circuit with a load impedance equal to this is connected to the output of the power combiner.

[0024] With the above configuration, when the input impedance values ​​for the first, second, and third inputs and the load impedance value seen from the output are given, impedance matching can be achieved by adjusting the line width so that the characteristic impedance of each line in this combiner circuit becomes equal to the dynamic impedance value of each coupling point. Since the line length can be selected arbitrarily, it is possible to arrange the inputs at equal intervals around the output.

[0025] The power combiner includes a second combining circuit that combines the outputs of the five power combiners and outputs the result to the first, second, and third input ports, and the second combining circuit combines the outputs of the first and second power combiners and outputs the result to the first input port, outputs the output of the third power combiner to the third input port, and combines the outputs of the fourth and fifth power combiners and outputs the result to the second input port.

[0026] According to the above configuration, the outputs of the five power combiners are combined and aggregated into three, and then output to the three input sections of the combining circuit, thereby making it possible to obtain a combined output of the five power combiners by utilizing the configuration of the circuit that combines three powers.

[0027] Although the present invention can essentially be implemented in a microstrip line, a strip line, or a coaxial line, the embodiments will be described taking as an example a case where the present invention is implemented in a microstrip line on a substrate.

[0028] The structure of a microstrip line is a high-frequency signal transmission line structure in which a dielectric layer εr of uniform thickness h is placed on a plane conductor that serves as the reference potential, and a signal conductor of thickness t with width w that matches the various characteristic impedances Zn (Ω) through which high-frequency signals are transmitted is placed on top of that (see Figure 6). The space above the signal conductor is a uniformly spreading high-frequency signal transmission line structure with H (5h~) that is sufficiently wide compared to the thickness h.

[0029] In addition, the values ​​of the various characteristic impedances shown in the embodiments are set such that the thickness h of the dielectric, the dielectric constant εr, the thickness t of the signal conductor, and the upper space H are fixed values, and the width w is a variable value. [Effects of the Invention]

[0030] According to the present invention, the line length can be adjusted by extending the line in the longitudinal direction of the board, so that the length of the board in the direction perpendicular to the longitudinal direction of the board can be shortened, thereby realizing the miniaturization of the entire circuit board. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a diagram showing the configuration of a power combiner according to the present invention. [Figure 2] FIG. 2 is a schematic diagram showing the layout of transmission lines on a substrate. [Figure 3] FIG. 10 is a diagram showing the configuration of a power combiner that combines the outputs of five power combiners. [Figure 4] FIG. 2 is a diagram showing a line pattern on a circuit board. [Figure 5] FIG. 10 is a diagram showing a line pattern on a circuit board in which the line lengths are equal. [Figure 6] FIG. 1 is a diagram illustrating a transmission line. BEST MODE FOR CARRYING OUT THE INVENTION

[0032] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0033] 1 is a diagram showing a power combiner 100 according to the present invention. The power combiner 100 includes a combiner unit 101 that combines and outputs a plurality of input signals, three input units 103a, 103b, and 103c to which three signals input to the combiner unit 101 are supplied, and an output unit 105 to which the signal combined by the combiner unit 101 is supplied. The combiner unit 101 has characteristic impedances indicated by Za, Zb, and Zc in the figure.

[0034] 2 is a schematic diagram showing the layout on a substrate of the transmission lines that make up the combiner 101. The transmission lines that make up the combiner 101 include lines that couple input ports Pin1, Pin2, and Pin3 to an output port Pout. In the figure, the input ports Pin1, Pin2, and Pin3 correspond to the input units 103a, 103b, and 103c shown in FIG. 1, and the output port Pout corresponds to the output unit 105 shown in FIG. 1.

[0035] The transmission line includes a first line having lines 201 and 215a that couple the input port Pin1 and the output port Pout, a second line having lines 203 and 235b that couple the input port Pin3 and the output port Pout, and a third line having lines 205a and 205b that couple the input port Pin2 and the output port Pout by branching the input port Pin2 arranged between the input ports Pin1 and Pin3 and coupling one end to the coupling point of the line 201 and the line 215a that constitute the first line and the other end to the coupling point of the line 203 and the line 235b that constitute the second line.

[0036] The third line is configured by connecting lines 205a and 205b branched from the input port Pin2 to the respective connection points that configure the first and second lines over the shortest distances.

[0037] In the transmission line of the above configuration, the signal I1 input to input port Pin1 passes through line 201, the signal input to input port Pin2 is branched, and one signal I2a passes through line 205a, the other signal I2b passes through line 205b, and the signal I3 input to input port Pin3 passes through line 203.

[0038] Signals I1 and I2a are introduced into line 215a, and their combined signal I12a is output through line 215a from output port Pout, and signals I3 and I2b are introduced into line 235b, and their combined signal I32b is output through line 235b from output port Pout.

[0039] 2, by making the length L1 of the line 201 in the longitudinal direction of the board equal to the length L2 of the line 205a, the length of the line through which the signal I1 passes and the length of the line through which the signal I2a passes can be made equal. As a result, the signal I1 input to the input port Pin1 and the signal I2a input to the input port Pin2 are combined with their phases aligned, and the combined signal I12a is output from the output port Pout.

[0040] Similarly, by making the length L1 of the line 203 in the board longitudinal direction equal to the length L2 of the line 205b, the length of the line through which the signal I3 passes can be made equal to the length of the line 205b through which the signal I2b passes. As a result, the signal input to the input port Pin3 and the signal I2b input to the input port Pin2 are combined with their phases aligned, and the combined signal I32b is output from the output port Pout.

[0041] In order to make the lengths L1 and L2 of each line equal, the input port Pin1 and the input port Pin3 are arranged symmetrically with respect to the virtual line Lv connecting the output port Pout and the input port Pin2, the first line and the second line are arranged symmetrically with respect to the virtual line Lv, and one line 205a and the other line 205b of the third line are arranged symmetrically with respect to the virtual line Lv.

[0042] In the transmission line of the above configuration, the line 201 from the input port Pin1 to the junction with the line 205a and the line 203 from the input port Pin3 to the junction with the line 205b have the same characteristic impedance Za, which is configured to be equal in width to each other, and is equal to the output standard impedance as seen from the power amplifier (see Figure 1).

[0043] Furthermore, the line 205a and the line 205b are configured with a width that provides an impedance that is approximately twice that of the line 201 or the line 203, and each have the same characteristic impedance Zb (see FIG. 1).

[0044] The line 215a from the junction between the line 201 and the line 205a to the output port Pout and the line 235b from the junction between the line 203 and the line 205b to the output port Pout are configured to have the same width, and are configured with a width that results in a characteristic impedance Zc that is equal to the parallel value of Za and Zb, which are the operating impedances of each junction (see Figure 1).

[0045] With the above configuration, signals input to each input port are output to the output port Pout via lines of equal length, thereby enabling signals to be output from the output port Pout without any combined loss.

[0046] The board on which the power combiner of the present invention is mounted has first, second, and third input ports arranged along the length of the board to correspond to the three power combiners arranged along the length of the board. Because multiple input ports are provided along the length of the board, there is space for extending lines along the length of the board to adjust their lengths. By utilizing this space to adjust the line lengths, it is possible to arrange lines of the desired length without enlarging the board.

[0047] As shown in the embodiment, a power combiner may be connected to each of the three input ports, or alternatively, lines may be provided to supply combined power from a plurality of power combiners to the three input ports.

[0048] 3 shows a power combiner 300 that combines the outputs of five power combiners. Power combiner 300 includes a first combining circuit 301, first to fifth input ports 303a, 303b, 303c, 303d, and 303e that are arranged in the longitudinal direction of the substrate corresponding to the five power combiners, a second combining circuit that combines the powers input to the input ports and outputs the combined power to the first combining circuit, and an output port 305 that outputs the power combined by the first combining circuit.

[0049] First combining circuit 301 has the configuration of combining circuit 101 shown in Fig. 1. That is, first combining circuit 301 has first, second, and third input ports, and includes a line that outputs from an output port a combined signal of a signal input to the first input port and one of the signals input to the second input port and branched, and a line that outputs from the output port a combined signal of a signal input to the third input port and the other of the signals input to the second input port and branched.

[0050] Second combining circuit 307 combines the outputs of the five power amplifiers and outputs the result to the first, second, and third input ports of first combining circuit 301. Second combining circuit 307 combines the outputs of first and second power amplifiers selected from the five power amplifiers (inputs at input ports 303a and 303b) and outputs the result to the first input port of first combining circuit 301, outputs the output of a third power amplifier selected from the five power amplifiers (input at input port 303c) to the second input port of first combining circuit 301, and combines the outputs of the remaining fourth and fifth power amplifiers (inputs at input ports 303d and 303e) and outputs the result to the third input port of first combining circuit 301.

[0051] 3, the outputs of five power amplifiers are combined into three outputs in advance, and the combined outputs of the three power amplifiers are combined into one output. By making the lines Zd of the second combining circuit all equal in length, that is, by arranging input ports 303a, 303b, 303c, 303d, and 303e at equal intervals around an imaginary line connecting input port 303c and output port 305, so that the three outputs combined and combined by the second combining circuit have approximately the same phase, the first combining circuit can deliver a combined output to output port 305 without any combining loss.

[0052] Furthermore, when combining the outputs of multiple power combiners, in addition to the configuration in which the outputs of the multiple power combiners are aggregated into three and output to the first combining circuit as shown in Figure 3, it is also possible to aggregate the outputs of the power combiners into five in advance of the second combining circuit, combine them into three in the second combining circuit, and then combine them into one in the first combining circuit. By connecting multiple combining circuits in cascade, flexible design is possible even when the number of power combiners to be combined increases.

[0053] According to the embodiment described above, it is possible to combine the outputs of a plurality of power combiners. When combining the outputs of an even number of power combiners, the power can be combined without causing a phase shift. Therefore, the power combining according to the present invention can be particularly effective when combining the outputs of an odd number of power combiners. [Industrial Applicability]

[0054] It can be used in a power combiner that combines the power of high-frequency signals. [Explanation of symbols]

[0055] 100, 300 power combiner 101 Synthesis circuit 103a, 103b, 103c Input section 105 Output section 201, 203, 205a, 205b, 215a, 235b tracks 301 First synthesis circuit 303 input port 305 output port 307 Second synthesis circuit Pin1, Pin2, Pin3 input port Pout output port

Claims

1. A power combiner is provided on a circuit board to which outputs of a plurality of power amplifiers arranged in the longitudinal direction of the circuit board are supplied in approximately the same phase, and the circuit board is provided with first, second and third input sections arranged in the longitudinal direction of the circuit board corresponding to each power amplifier, a combining circuit that combines the powers input to each input section, and an output section that outputs the power combined by the combining circuit, and the lengths of the lines connecting each input section and the output section are configured to be approximately equal, wherein the combining circuit comprises: a first line having a line coupling the first input section and the output section; a second line having a line coupling the third input portion and the output portion; a third line that branches the second input section, which is disposed between the first input section and the third input section, and has one branch coupled to the first line and the other branch coupled to the second line, thereby coupling the second input section and the output section; A power combiner comprising:

2. 2. The power combiner according to claim 1, wherein the third line is configured by connecting a line branching from the second input port to the first and second lines at the shortest distance.

3. 2. The power combiner according to claim 1, wherein the third line is configured such that one line coupled to the first line and the other line coupled to the second line are arranged in line symmetry.

4. the first input unit and the third input unit are arranged symmetrically with respect to a virtual line connecting the output unit and the second input unit arranged on the circuit board, the first line and the second line are arranged symmetrically with respect to the virtual line, 2. The power combiner according to claim 1, wherein one line and the other line of said third lines are arranged symmetrically with respect to said virtual line.

5. 2. The power combiner according to claim 1, wherein the third line has an impedance width that is approximately twice that of the first or second line.

6. a second combining circuit that combines outputs of the five power amplifiers and outputs the combined output to the first, second, and third input sections, and the second combining circuit combining outputs of the first and second power amplifiers and outputting the combined output to the first input section; outputting an output of a third power amplifier to the second input; 2. The power combiner according to claim 1, wherein the outputs of said fourth and fifth power amplifiers are combined and output to said third input section.

Images