Millimeter wave coaxial radial three-path power synthesis amplifier

Abstract

The invention relates to the technical field of radio frequency microwave circuits, and provides a millimeter wave coaxial radial three-path power synthesis amplifier, a three-path power divider circuit comprises a first coaxial line and three first circuit units, and a three-path power combiner circuit comprises a second coaxial line and three second circuit units. The number of the rectangular waveguide connection conversion circuits is the same as that of the second circuit units, the positions of the rectangular waveguide connection conversion circuits and the positions of the second circuit units are in one-to-one correspondence, and each rectangular waveguide connection conversion circuit is correspondingly connected with one first circuit unit and one second circuit unit and used for achieving signal transition transmission between the two circuit units; the power amplifier chip is directly arranged on the second circuit unit, amplified signals do not need to be converted through an additional guided wave structure, three paths of power are directly synthesized, and the technical indexes of higher synthesis efficiency and larger synthesis output power can be obtained; and the power loss caused by synthesis only by structure conversion after output of the amplifier in the prior art is avoided.

Description

Technical Field

[0001] This invention relates to the field of radio frequency microwave circuit technology, and in particular to a millimeter-wave coaxial radial three-way power combining amplifier. Background Technology

[0002] Millimeter-wave power amplifiers are core active devices in modern wireless communication, radar detection, and satellite communication systems. Their output power level directly determines the system's transmission distance, signal quality, and anti-interference capability. With the widespread application of millimeter-wave frequencies in 5G / 6G communication, high-speed data transmission, and imaging sensing, the demand for high-power, high-efficiency, and highly integrated millimeter-wave power amplifiers is becoming increasingly urgent.

[0003] Power combining technology is one of the effective ways to increase the output power of amplifiers. By superimposing the output signals of multiple power amplification units in phase, a higher total output power can be achieved than that of a single-channel amplifier. Common power combining methods include those based on Wilkinson power dividers, Lange couplers, waveguide combining, and spatial combining. As the operating frequency increases, entering the millimeter-wave band, power combining technology faces the challenge of significantly increased transmission line losses, dielectric losses, and radiation losses, leading to a decrease in combining efficiency. This is especially true in multi-channel combining, where the cumulative effect of losses is more pronounced. Furthermore, multi-channel signals require high phase consistency during combining, necessitating strict phase synchronization; otherwise, the combining efficiency may decrease or even the output power may be canceled out. Moreover, the extremely short wavelength of millimeter waves makes them highly susceptible to phase deviations due to circuit fabrication errors and material inhomogeneities, placing higher demands on design and manufacturing processes.

[0004] In terms of circuit structure, most common solid-state power combining amplifiers currently employ structures based on microstrip lines, rectangular waveguides, and coaxial lines, or combinations thereof. Microstrip lines are easy to assemble with power amplifier chips, can be directly integrated with other planar circuits, and are low in cost, but suffer from higher losses and limited power capacity in the millimeter-wave band. Rectangular waveguides have low losses and high power capacity, but are bulky and difficult to integrate with other planar circuits. Coaxial lines, as a classic transmission line structure, still offer advantages such as wide single-mode operating bandwidth, low loss, and high power capacity in the millimeter-wave band. Their radial structure can simultaneously realize multiple signal transmission channels, and due to their structural symmetry, they can fully guarantee the phase consistency of each signal transmission channel. Therefore, this structure occupies an important place in the application of power combining amplifier circuits.

[0005] In existing technologies, three-way power combining amplifiers implemented with a coaxial radial structure mainly employ a three-way equal power divider / power combiner circuit structure where one end is coaxial and the other end is a rectangular waveguide with equal included angles between the two ends. A microstrip circuit containing a power amplifier chip is connected between the three rectangular waveguide ports of each pair of circuits to achieve a three-way power combining amplifier with coaxial input and output ports. In this circuit structure, due to the different waveguide structures in each output branch after the power amplifier chip, a conversion circuit is needed for transition before power combining in each branch. The resulting power loss leads to a decrease in the combining efficiency of the power combining amplifier. Summary of the Invention

[0006] This invention provides a millimeter-wave coaxial radial three-way power combining amplifier. It employs a three-way power divider with coaxial input and three microstrip line outputs, a three-way power combiner with three microstrip line inputs and coaxial outputs, and a rectangular waveguide connection conversion circuit that uses a microstrip probe to connect the branches and transmit signals between the power divider and the power combiner. By utilizing power amplifier chips mounted on the three microstrip lines of the combiner, a coaxial radial three-way power combining amplifier circuit structure with higher combining efficiency and greater combined output power is achieved.

[0007] This invention provides a millimeter-wave coaxial radial three-way power combining amplifier, comprising: The three-way power divider circuit includes: The first coaxial cable is used to input signals along the first direction; The first circuit unit is provided in three parts. The three first circuit units are evenly distributed on the outer periphery of the first coaxial line along the circumferential direction, and are used to output the signal in three paths along the radial direction of the first coaxial line. A three-way power combiner circuit includes: The second coaxial cable is used to output the signal along the first direction; The second circuit unit comprises three units. Each second circuit unit is equipped with a 50-ohm characteristic impedance microstrip line and a power amplifier chip. The power amplifier chip is mounted on the 50-ohm characteristic impedance microstrip line for amplifying signal power and outputting it. The three second circuit units are evenly distributed around the second coaxial line in a circumferential direction, for transmitting the signal in three separate radial paths to the second coaxial line. Furthermore, along the first direction, the positions of the second circuit units correspond one-to-one with those of the first circuit units. A rectangular waveguide connection conversion circuit is provided, wherein the number of the rectangular waveguide connection conversion circuits is the same as the number of the second circuit units and their positions correspond one-to-one. Each rectangular waveguide connection conversion circuit is respectively connected to one first circuit unit and one second circuit unit, which is used to realize signal transition transmission between the two circuit units. The terminals of the first coaxial cable and the second coaxial cable are short-circuited.

[0008] According to the millimeter-wave coaxial radial three-way power combining amplifier provided by the present invention, each of the rectangular waveguide-connected conversion circuits includes: A rectangular waveguide, wherein both ends of the rectangular waveguide are closed, and the same side of the rectangular waveguide is connected to the first circuit unit through a first microstrip-waveguide conversion structure and to the second circuit unit through a second microstrip-waveguide conversion structure.

[0009] According to the millimeter-wave coaxial radial three-way power combining amplifier provided by the present invention, the first microstrip-waveguide conversion structure is a first microstrip probe circuit, the second microstrip-waveguide conversion structure is a second microstrip probe circuit, and both the first microstrip probe circuit and the second microstrip probe circuit are inserted from the same wide side of the rectangular waveguide.

[0010] The millimeter-wave coaxial radial three-way power combining amplifier provided by the present invention further includes: A first dielectric substrate is disposed along a second direction between the first coaxial line and each of the rectangular waveguides. The first circuit unit and the first microstrip-waveguide conversion structure are disposed on the surface of the first dielectric substrate. The second direction is perpendicular to the first direction. The second dielectric substrate is disposed between the second coaxial line and each of the rectangular waveguides along the second direction, and the second circuit unit and the second microstrip-waveguide conversion structure are disposed on the surface of the second dielectric substrate.

[0011] According to the millimeter-wave coaxial radial three-way power combining amplifier provided by the present invention, the outer conductor metal sidewall of the first coaxial line is provided with three first opening slots at equal angles along the circumference for the first circuit unit to pass through; one end of the first circuit unit extends into the first coaxial line, and the other end of the first circuit unit is connected to the first microstrip probe circuit.

[0012] According to the millimeter-wave coaxial radial three-way power combining amplifier provided by the present invention, the outer conductor metal sidewall of the second coaxial line is provided with three second opening slots at equal angles along the circumference for the passage of the second circuit unit; one end of the second circuit unit extends into the second coaxial line, and the other end of the second circuit unit is connected to the second microstrip probe circuit.

[0013] According to the millimeter-wave coaxial radial three-way power combining amplifier provided by the present invention, each of the first circuit units includes a first coaxial probe, a first microstrip line and a first impedance transformation circuit connected coaxially in sequence, and the first coaxial probe extends radially into the first coaxial line and extends to the outside of the metal sidewall of the first coaxial line through the first microstrip line, and the end of the first impedance transformation circuit is connected to the first microstrip probe circuit.

[0014] According to the millimeter-wave coaxial radial three-way power combining amplifier provided by the present invention, each second circuit unit includes a second coaxial probe, a second microstrip line, a second impedance transformation circuit, the 50-ohm characteristic impedance microstrip line, and a third impedance transformation circuit connected coaxially in sequence. The second coaxial probe extends radially into the second coaxial line and extends to the outside of the metal sidewall of the second coaxial line through the second microstrip line. The end of the third impedance transformation circuit is connected to the second microstrip probe circuit.

[0015] The millimeter-wave coaxial radial three-way power combining amplifier provided by the present invention further includes a PCB power supply circuit, which is disposed on the back side of the second dielectric substrate and is used to supply power to the power amplifier chip.

[0016] This invention provides a millimeter-wave coaxial radial three-channel power combining amplifier. By evenly distributing three first circuit units along the circumference of a first coaxial line and three second circuit units along the circumference of a second coaxial line, with each first and second circuit unit positioned in a one-to-one correspondence along a first direction, and connecting them via three identical rectangular waveguide conversion circuits with consistent transmission characteristics, the input signal, transmitted from the input end of the first coaxial line to the second circuit unit, ensures sufficient phase consistency among the three channels at the same location on the three 50-ohm characteristic impedance microstrip lines. By directly placing the power amplifier chip in the second circuit unit, the power of each signal, after being amplified individually, does not require additional waveguide conversion. It can directly combine the three channels radially into the second coaxial line through the second circuit unit, achieving higher combining efficiency and greater combined output power. This avoids the power loss caused by the need for structural conversion after amplifier output in existing technologies.

[0017] Furthermore, since the rectangular waveguide connection conversion circuit is only used as a transition transmission channel for signals, a more compact circuit structure can be achieved between the coaxial input and output of the power combining amplifier. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 A three-dimensional structural schematic diagram of a millimeter-wave coaxial radial three-way power combining amplifier provided for an embodiment of the present invention; Figure 2 This is a schematic diagram of the basic circuit structure of the three-way power divider and combiner used in the embodiments of the present invention; Figure 3 This is a schematic diagram of the rectangular waveguide connection conversion circuit provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the circuit structure on any one of the first dielectric substrates provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the circuit structure on any second dielectric substrate provided in an embodiment of the present invention; Figure 6 for Figure 2 Simulation results of a three-way power divider or combiner circuit; Figure 7 for Figure 3 Simulation results of the rectangular waveguide-connected conversion circuit; Figure 8 for Figure 1 Simulation results of signal transmission between input and output of a power combining amplifier before the addition of a power amplifier chip; Figure 9 This is a physical image of a three-way power combiner after power amplifier chips have been assembled on it, as provided in an embodiment of the present invention. Figure 10 A physical diagram of the PCB power supply board circuit for the power combining amplifier provided in an embodiment of the present invention; Figure 11 A physical diagram of the power combining amplifier provided in an embodiment of the present invention; Figure 12 The figure shows the measured output power of a millimeter-wave coaxial radial three-way power combining amplifier provided in an embodiment of the present invention.

[0020] Figure label: 1. Three-way power divider circuit; 11. First coaxial line; 12. First dielectric substrate; 13. First circuit unit; 131. First coaxial probe; 132. First microstrip line; 133. First impedance transformation circuit; 2. Three-way power combiner circuit; 21. Second coaxial line; 22. Second dielectric substrate; 23. Second circuit unit; 231. Second coaxial probe; 232. Second microstrip line; 233. Second impedance transformation circuit; 234. 50-ohm characteristic impedance microstrip line; 235. Third impedance transformation circuit; 3. Rectangular waveguide connection conversion circuit; 31. Rectangular waveguide; 32. First microstrip probe circuit; 33. Second microstrip probe circuit; 4. First opening groove; 5. Second opening groove. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0022] The following is combined with Figures 1 to 12 This invention describes a millimeter-wave coaxial radial three-way power combining amplifier.

[0023] like Figure 1 As shown in the figure, this embodiment provides a millimeter-wave coaxial radial three-way power combining amplifier, including a three-way power divider circuit 1, a rectangular waveguide connection conversion circuit 3, and a three-way power combiner circuit 2.

[0024] The three-way power divider circuit 1 includes a first coaxial line 11 and three first circuit units 13. The first coaxial line 11 is used to input signals along a first direction, which is the same as the axial direction of the first coaxial line 11. The three first circuit units 13 are evenly distributed on the outer periphery of the first coaxial line 11 along the circumferential direction, that is, the included angle between two adjacent first circuit units 13 is 120°, which is used to output the signals in three paths along the radial direction of the first coaxial line 11.

[0025] The three-way power combiner circuit 2 includes a second coaxial line 21 and three second circuit units 23. The second coaxial line 21 is used to output the signal along the first direction. Each second circuit unit 23 is provided with a 50-ohm characteristic impedance microstrip line 234 and a power amplifier chip. The power amplifier chip is mounted on the 50-ohm characteristic impedance microstrip line 234 and is used to amplify the signal power and output it. The three second circuit units 23 are evenly distributed around the second coaxial line 21 in a circumferential direction, that is, the included angle between two adjacent second circuit units 23 is 120°, which is used to transmit the signal in three paths radially to the second coaxial line 21. In addition, along the first direction, the positions of the second circuit units 23 correspond one-to-one with the positions of the first circuit units 13. That is to say, the positions of the three second circuit units 23 correspond one-to-one with the positions of the three first circuit units 13, which facilitates the transition and connection of each signal transmission channel and ensures the consistency of phase, thereby optimizing the power combining efficiency.

[0026] The number of rectangular waveguide connection conversion circuits 3 is the same as the number of second circuit units 23 and their positions correspond one-to-one. Each rectangular waveguide connection conversion circuit 3 is connected to a first circuit unit 13 and a second circuit unit 23 respectively, which is used to realize the signal transition transmission between the two circuit units.

[0027] This invention uses three first circuit units 13 evenly distributed along the circumference of the first coaxial line 11 and three second circuit units 23 evenly distributed along the circumference of the second coaxial line 21, with the positions of the three first circuit units 13 and the three second circuit units 23 corresponding one-to-one along the first direction. After being connected by three rectangular waveguide connection conversion circuits 3 with identical structures and consistent transmission characteristics, when the input signal is transmitted from the input end of the first coaxial line 11 to the second circuit unit 23, the phase consistency between the three 50-ohm characteristic impedance microstrip lines can be fully guaranteed at the same position. By directly placing the power amplifier chip in the second circuit unit 23, the power of each signal is amplified separately and does not need to go through an additional waveguide structure conversion. It can be directly combined into the second coaxial line 21 radially through the second circuit unit 23, avoiding the power loss caused by the need for structure conversion after the amplifier output in the prior art.

[0028] As can be seen from the above scheme, the millimeter-wave coaxial radial three-way power combining amplifier provided by the present invention, by mounting the power amplifier chip on the three-way power combiner circuit 2, can directly combine the three-way power at the power output end of the power amplifier chip, achieving higher combining efficiency and greater combined output power. Furthermore, since the rectangular waveguide connection conversion circuit 3 is only used for signal transition transmission, a more compact circuit structure can be achieved between the coaxial input and output of the power combining amplifier.

[0029] It should be noted that, as Figure 2 As shown, the power combiner and power divider in this embodiment have the same basic circuit structure. Both use a coaxial cable as the centralized signal transmission carrier and are composed of three dielectric substrates mounted on a plane perpendicular to the signal transmission direction of the coaxial cable, arranged at 120° intervals radially along the coaxial cable. Figure 2 The simplified synthesis or power division basic circuit structure of the dielectric substrate circuit is respectively used as... Figure 4 The circuitry on the first dielectric substrate and Figure 5 After the circuit on the second dielectric substrate is replaced, it constitutes the three-way power divider circuit 1 and the three-way power combiner circuit 2 in this embodiment. The only difference is the composition of the circuit units set on their respective dielectric substrates.

[0030] Reference Figure 1 , Figure 3 In this embodiment, each rectangular waveguide connection conversion circuit 3 includes a rectangular waveguide 31. The two ends of the rectangular waveguide 31 are closed. The same side of the rectangular waveguide 31 is connected to the first circuit unit 13 through a first microstrip-waveguide conversion structure and to the second circuit unit 23 through a second microstrip-waveguide conversion structure. Specifically, the first microstrip-waveguide conversion structure is a first microstrip probe circuit 32, and the second microstrip-waveguide conversion structure is a second microstrip probe circuit 33. Both the first microstrip probe circuit 32 and the second microstrip probe circuit 33 are inserted from the same wide side of the rectangular waveguide 31.

[0031] This embodiment also includes a first dielectric substrate 12 and a second dielectric substrate 22. The first dielectric substrate 12 is disposed between the first coaxial line 11 and each rectangular waveguide 31 along a second direction, and the first circuit unit 13 and the first microstrip-waveguide conversion structure are disposed on the surface of the first dielectric substrate 12. The second dielectric substrate 22 is disposed between the second coaxial line 21 and each rectangular waveguide 31 along a second direction, and the second circuit unit 23 and the second microstrip-waveguide conversion structure are disposed on the surface of the second dielectric substrate 22. The second direction is perpendicular to the first direction, that is, the surface of the dielectric substrate is parallel to the cross-section of the coaxial line.

[0032] like Figure 1 As shown, the first dielectric substrate 12 is configured as a strip structure, and three of them are provided. The three first dielectric substrates 12 are also evenly distributed along the circumferential direction on the outer periphery of the first coaxial line 11, that is, the included angle between two adjacent first dielectric substrates 12 is 120°; the second dielectric substrate 22 is configured as a strip structure, and three of them are provided. The three second dielectric substrates 22 are also evenly distributed along the circumferential direction on the outer periphery of the second coaxial line 21, that is, the included angle between two adjacent second dielectric substrates 22 is 120°.

[0033] Furthermore, the terminals of the first coaxial cable 11 and the second coaxial cable 21 are short-circuited.

[0034] like Figure 1 As shown, the outer conductor metal sidewall of the first coaxial line 11 is provided with three first opening slots 4 at equal angles along the circumference for the first circuit unit 13 to pass through; one end of the first circuit unit 13 extends into the first coaxial line 11, and the other end of the first circuit unit 13 is connected to the first microstrip probe circuit 32.

[0035] Similarly, the outer conductor metal sidewall of the second coaxial line 21 is provided with three second opening slots 5 at equal angles along the circumference for the second circuit unit 23 to pass through; one end of the second circuit unit 23 extends into the second coaxial line 21, and the other end of the second circuit unit is connected to the second microstrip probe circuit 33.

[0036] Reference Figure 4 In this embodiment, each first circuit unit 13 includes a first coaxial probe 131, a first microstrip line 132 and a first impedance transformation circuit 133 connected coaxially in sequence. The first coaxial probe 131 extends radially into the first coaxial line 11 and extends to the outside of the metal sidewall of the first coaxial line 11 through the first microstrip line 132. The end of the first impedance transformation circuit 133 is connected to the first microstrip probe circuit 32.

[0037] Reference Figure 5 In this embodiment, each second circuit unit 23 includes a second coaxial probe 231, a second microstrip line 232, a second impedance transformation circuit 233, a 50-ohm characteristic impedance microstrip line 234, and a third impedance transformation circuit 235 connected coaxially in sequence. The second coaxial probe 231 extends radially into the second coaxial line 21 and extends to the outside of the metal sidewall of the second coaxial line 21 through the second microstrip line 232. The end of the third impedance transformation circuit 235 is connected to the second microstrip probe circuit 33.

[0038] Furthermore, the three second circuit units 23 are evenly distributed along the circumference of the second coaxial line 21, and the structure of each unit is completely identical, ensuring that the impedance distribution and transmission path length of the three branches are exactly the same; the second coaxial probes 231 all extend radially into the second coaxial line 21, and the insertion depth and the length of the second microstrip line 232 extending to the outer sidewall are uniform, so that the signal phases of the three paths are completely synchronized when they converge into the second coaxial line 21; the line width and length of the two impedance transformation circuits are consistent, avoiding the introduction of additional phase deviation due to differences in impedance transformation characteristics.

[0039] In some specific embodiments, the power amplifier chip is mounted on a 50-ohm characteristic impedance microstrip line for amplifying signal power and outputting it.

[0040] Furthermore, it also includes a PCB power supply circuit, which is disposed on the back side of the second dielectric substrate 22 and is used to supply power to the power amplifier chip.

[0041] In one specific embodiment, a Ka-band coaxial radial three-way power combining amplifier circuit is used as an example. The dielectric substrate used in this embodiment is Rogers RT / duroid 5880 with a thickness of 0.254mm; the power amplifier chip selected is TCC2011A from Hebei Xiong'an Taixin Electronic Technology Group, which has a nominal saturated output power of 28-31dBm in the frequency range of 15-43GHz.

[0042] right Figure 2 The three-way power divider / combiner basic circuit shown was subjected to preliminary optimization simulation design, and the simulation results are as follows: Figure 6 As shown; by Figure 6 It can be seen that, within the entire Ka band, after deducting the inherent 4.8dB loss of each branch, the insertion loss of each branch of the three-way power divider / synthesizer circuit is less than 0.09dB, and the input return loss is better than -24dB.

[0043] Figure 7 Yes Figure 3 The diagram shows the optimized simulation design of the rectangular waveguide connection conversion circuit. Figure 7 It can be seen that the rectangular waveguide connecting the conversion circuit, which involves two transition conversions and has a microstrip line input, a rectangular waveguide output, and a microstrip line input, has an insertion loss of less than 0.07dB and an input return loss of better than -30dB in the entire Ka band.

[0044] Based on the circuit simulation design work described above, respectively using Figure 4 , Figure 5 Replacement of circuit structure on dielectric substrate Figure 2 The three-way power distribution / combiner circuit is structured as follows: after inserting the microstrip probe circuits of each of the three power branches and the three combining branches into the rectangular waveguide connection conversion circuit 3 of the corresponding transmission channel, it forms a circuit as shown in Figure 3. Figure 1 The inputs and outputs shown are all coaxial cables, and the synthesizer consists of three branches, representing the passive circuit architecture of a power combining amplifier before the addition of a power amplifier chip. After overall optimization and simulation design of the passive circuit of this architecture, the simulation results are as follows: Figure 8 As shown.

[0045] Depend on Figure 8 It can be seen that, Figure 1 The passive circuit of the power combining amplifier shown in this embodiment has an insertion loss of less than 0.4dB and an input return loss that is generally better than -20dB throughout the entire Ka band.

[0046] like Figure 9The image shown is a physical diagram of the power amplifier chip assembled on the 50-ohm microstrip line of the three branches of the synthesizer in this embodiment.

[0047] like Figure 10 The image shown is a physical diagram of the PCB power board circuit assembled in this embodiment.

[0048] Figure 11 The image shown is a physical diagram of the power combining amplifier provided in this embodiment.

[0049] Figure 12 The above are the test results of the combined output power of the power combining amplifier in this embodiment. The measured results show that the Ka-band three-channel power combining amplifier in this embodiment has an average saturated output power of 34.28 dBm in the frequency range of 26.5-40 GHz, and a typical combining efficiency of 89.3%.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A millimeter-wave coaxial radial three-way power combining amplifier, characterized in that, include: The three-way power divider circuit (1) includes: The first coaxial cable (11) is used to input signals along the first direction; The first circuit unit (13) is provided in three parts. The three first circuit units (13) are evenly distributed on the outer periphery of the first coaxial line (11) along the circumferential direction, and are used to output the signal in three paths along the radial direction of the first coaxial line (11). The three-way power combiner circuit (2) includes: The second coaxial cable (21) is used to output the signal along the first direction; The second circuit unit (23) is provided in three parts. Each second circuit unit (23) is provided with a 50-ohm characteristic impedance microstrip line (234) and a power amplifier chip. The power amplifier chip is mounted on the 50-ohm characteristic impedance microstrip line (234) and is used to amplify the signal power and output it. The three second circuit units (23) are evenly distributed around the second coaxial line (21) in the circumferential direction and are used to transmit the signal in three paths along the radial direction of the second coaxial line (21) to the second coaxial line (21). In addition, along the first direction, the positions of the second circuit units (23) correspond one-to-one with the positions of the first circuit units (13). The rectangular waveguide connection conversion circuit (3) has the same number as the second circuit unit (23) and the positions correspond one-to-one. Each rectangular waveguide connection conversion circuit (3) is connected to one first circuit unit (13) and one second circuit unit (23) respectively, so as to realize the signal transition transmission between the two circuit units. The first coaxial cable (11) and the second coaxial cable (21) are short-circuited at their terminals.

2. The millimeter-wave coaxial radial three-way power combining amplifier according to claim 1, characterized in that, Each of the rectangular waveguide connection conversion circuits (3) includes: A rectangular waveguide (31) is provided with closed waveguide ports at both ends. The same side of the rectangular waveguide (31) is connected to the first circuit unit (13) through a first microstrip-waveguide conversion structure and to the second circuit unit (23) through a second microstrip-waveguide conversion structure.

3. The millimeter-wave coaxial radial three-way power combining amplifier according to claim 2, characterized in that, The first microstrip-waveguide conversion structure is a first microstrip probe circuit (32), and the second microstrip-waveguide conversion structure is a second microstrip probe circuit (33). Both the first microstrip probe circuit (32) and the second microstrip probe circuit (33) are inserted from the same wide side of the rectangular waveguide (31).

4. The millimeter-wave coaxial radial three-way power combining amplifier according to claim 2, characterized in that, Also includes: A first dielectric substrate (12) is disposed between the first coaxial line (11) and each of the rectangular waveguides (31) along a second direction. The first circuit unit (13) and the first microstrip-waveguide conversion structure are disposed on the surface of the first dielectric substrate (12). The second direction is perpendicular to the first direction. The second dielectric substrate (22) is disposed between the second coaxial line (21) and each of the rectangular waveguides (31) along the second direction, and the second circuit unit (23) and the second microstrip-waveguide conversion structure are disposed on the surface of the second dielectric substrate (22).

5. The millimeter-wave coaxial radial three-way power combining amplifier according to claim 3, characterized in that, The outer conductor metal sidewall of the first coaxial line (11) is provided with three first opening slots (4) at equal angles along the circumference for the first circuit unit (13) to pass through; one end of the first circuit unit (13) extends into the first coaxial line (11), and the other end of the first circuit unit is connected to the first microstrip probe circuit (32).

6. The millimeter-wave coaxial radial three-way power combining amplifier according to claim 3, characterized in that, The outer conductor metal sidewall of the second coaxial line (21) is provided with three second opening slots (5) at equal angles along the circumference for the second circuit unit (23) to pass through; one end of the second circuit unit (23) extends into the second coaxial line (21), and the other end of the second circuit unit is connected to the second microstrip probe circuit (33).

7. The millimeter-wave coaxial radial three-way power combining amplifier according to claim 5, characterized in that, Each of the first circuit units (13) includes a first coaxial probe (131), a first microstrip line (132) and a first impedance transformation circuit (133) connected coaxially in sequence. The first coaxial probe (131) extends radially into the first coaxial line (11) and extends to the outside of the metal sidewall of the first coaxial line (11) through the first microstrip line (132). The end of the first impedance transformation circuit (133) is connected to the first microstrip probe circuit (32).

8. The millimeter-wave coaxial radial three-way power combining amplifier according to claim 6, characterized in that, Each of the second circuit units (23) includes a second coaxial probe (231), a second microstrip line (232), a second impedance transformation circuit (233), the 50-ohm characteristic impedance microstrip line (234), and a third impedance transformation circuit (235) connected coaxially in sequence. The second coaxial probe (231) extends radially into the second coaxial line (21) and extends through the second microstrip line (232) to the outside of the metal sidewall of the second coaxial line (21). The end of the third impedance transformation circuit (235) is connected to the second microstrip probe circuit (33).

9. The millimeter-wave coaxial radial three-way power combining amplifier according to claim 1, characterized in that, It also includes a PCB power supply circuit, which is disposed on the back side of the second dielectric substrate (22) and is used to supply power to the power amplifier chip.

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