Wide waveguide coupling broadband high-power capacity power divider
By employing a wide rectangular waveguide structure with built-in double-row pins and an optimized stepped transition design in the power divider, the problem of insufficient bandwidth and power capacity in existing power dividers is solved, and a broadband high-power capacity power divider design is realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-21
- Publication Date
- 2026-03-27
AI Technical Summary
Existing power dividers, when the number of output rectangular waveguides is small, face problems such as narrow operating bandwidth and insufficient power capacity due to competition of angular asymmetric modes and excitation of higher-order modes.
A wide rectangular waveguide with built-in double-row pins is used as the coupling structure. Combined with optimized stepped transition and rounded/beveled design, broadband impedance matching and internal electric field homogenization are achieved, suppressing higher-order modes and angular asymmetric modes, and improving power capacity.
It significantly broadens the operating bandwidth of the power divider and increases its power capacity, while avoiding local electric field concentration, making it suitable for long-term reliable operation in high-power environments.
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Figure CN121748751A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of power distribution technology in the field of high-power microwave technology, and specifically relates to a broadband high-power capacity power divider based on wide waveguide coupling. Background Technology
[0002] Power dividers are passive devices commonly used in high-power microwave applications, constructed from circular waveguides (TM). 01 Multi-channel rectangular waveguides TE with orthogonal mode orientation 10 Power dividers that distribute power in modes have the advantages of short axial length and high power capacity, and are widely used in power dividing networks for high-power array antennas. With the continuous development of high-power microwave technology, higher demands are being placed on the power capacity and operating bandwidth of power dividers. Generally, for a given operating frequency band, appropriately increasing the number of branch rectangular waveguides is beneficial to improving the power capacity and operating bandwidth of the power divider. However, when the number of branch rectangular waveguides is relatively small, such as 2-way or 4-way, the power divider faces the challenge of balancing power capacity and operating bandwidth. This is mainly because fewer rectangular waveguides are more likely to excite low-order angular asymmetric competing modes, such as TE... 11 TE 21 Modes, etc. Competing modes can be suppressed by reducing the cross-sectional size of the circular waveguide, but this will reduce power capacity. Common solutions are to merge branch rectangular waveguide ports and introduce coaxial waveguide sections. The former is used to suppress low-order angular asymmetric modes and reduce the number of output ports, while the latter is used to increase the cross-sectional size of the power divider and improve power capacity.
[0003] Reference [1] studied a power divider from an S-band overmode coaxial waveguide to a two-way rectangular waveguide (Men Manzhou. S-band high-power 1-to-32-way power distribution network [D]. Chengdu: Southwest Jiaotong University, 2013.), as shown in the appendix. Figure 1 As shown, the system includes a coaxial waveguide 1, a coupling waveguide 2, an HT branch 3, and an output rectangular waveguide 4. High-power TEM mode microwaves are injected through the coaxial circular waveguide 1 and converted to four rectangular waveguide TE signals via mode matching at the coupling waveguide 2. 10 The mode is then used to combine the four coupled waveguides into two BJ32 output rectangular waveguides 4 via HT branch 3. This power divider indirectly outputs two rectangular waveguides TE using a combination of four coupled outputs and two-to-two merging. 10 The four-way coupling helps suppress angular asymmetric mode competition within the coaxial waveguide, thus enabling the use of a larger coaxial waveguide cross-section, achieving a designed power capacity of 4.5GW. However, after adding a conversion structure from the coaxial waveguide to the circular waveguide, the power divider's power capacity drops to 3.6GW, and the 99% conversion efficiency is reduced to a relative bandwidth of approximately 6%. Especially when extending to higher frequencies such as the X-band, the power divider's cross-sectional size decreases significantly, leading to a substantial drop in power capacity.
[0004] Reference [2] studied a power divider from an X-band circular waveguide to a four-way rectangular waveguide (Li Xiaomeng. Research on High-Power Overmode Waveguide Power Transmission and Distribution Technology [D]. Chengdu: Southwest Jiaotong University, 2018.), as shown in the appendix. Figure 2 As shown, it includes a circular waveguide 1, a coaxial waveguide 2, a sector waveguide 3, and an overmode rectangular waveguide 4. The circular waveguide 1 is located at the very front of the structure. 01 High-power microwaves are injected here, and the circuit is realized at the entrance of coaxial waveguide 2 via a circular waveguide TM. 01 The conversion to the coaxial waveguide TEM mode is achieved by introducing a sector waveguide 3 to suppress the angular asymmetric mode in coaxial waveguide 2, thereby improving the conversion from the coaxial waveguide 2 TEM mode to the overmode rectangular waveguide 4 TE mode. 10 Regarding the mode conversion efficiency, the power divider achieves a 99% conversion efficiency relative to a bandwidth of approximately 9.5%. Since both circular and rectangular waveguides are overmode structures, the power divider's power capacity is increased to some extent, with a designed power capacity of approximately 2.9GW. However, higher-order modes are easily excited within the overmode rectangular waveguide, and electric field concentration exists inside the fan-shaped waveguide and at the conductor end faces within the coaxial waveguide, thus limiting further increases in operating bandwidth and power capacity.
[0005] In summary, when the number of output rectangular waveguides is small, power dividers based on existing technologies face problems such as narrow operating bandwidth and insufficient power capacity caused by mode competition and local electric field concentration, which limit the application of such devices in broadband high-power capacity scenarios. Summary of the Invention
[0006] (a) Technical problems to be solved The present invention aims to solve the technical problems of narrow operating bandwidth and insufficient power capacity of power dividers when the number of output rectangular waveguides is small, due to asymmetric mode competition in the inner corner of the circular waveguide, excitation of higher-order modes in the wide waveguide, and local electric field concentration.
[0007] (II) Technical Solution To address the aforementioned issues, this invention proposes a wide-waveguide-coupled broadband high-power capacity power divider. The core idea of this power divider is to employ a wide rectangular waveguide with built-in double-row pins as the coupling structure. These pins electrically divide the wide waveguide into multiple narrow channels, thereby simultaneously suppressing higher-order modes within the wide waveguide and angular asymmetric modes within the input circular waveguide. Simultaneously, combined with an optimized stepped transition structure and multiple rounded / beveled designs, broadband impedance matching and internal electric field homogenization are achieved, thus significantly increasing power capacity while widening the operating frequency band.
[0008] The technical solution of the present invention is as follows: A wide-waveguide coupled broadband high-power capacity power divider, as shown in the attached figure. Figure 3As shown, it includes an input circular waveguide 1, a sloping short-circuit wall 2, a coupling wide waveguide 3, a double row of pins 4, a stepped transition 5, and a rectangular waveguide 6.
[0009] Input circular waveguide 1 is used as the microwave input port for injecting TM. 01 High-power microwave mode.
[0010] A sloping short-circuit wall 2 is located at the end of the input circular waveguide 1, and its sloping design is used to realize the short circuit from the circular waveguide TM. 01 Mode to subsequent waveguide TE 10 Efficient matching and conversion of dominant modes.
[0011] The coupled wide waveguide 3 is a wide rectangular waveguide with a cross-sectional width significantly larger than that of a standard rectangular waveguide. Its entrance end is connected to the input circular waveguide 1 and the inclined short-circuit wall 2. This wide waveguide design helps to improve the power capacity of the structure.
[0012] Double rows of pins 4 are fixed inside the coupled wide waveguide 3. These two rows of pins are arranged along the microwave propagation direction, effectively dividing the wide coupled waveguide 3 into several parallel, narrower waveguide channels in the width direction. This design cleverly suppresses easily excited high-order transmission modes in the wide waveguide without physically dividing the waveguide. At the same time, due to the increased number of equivalent channels, the suppression capability of angular asymmetric competing modes in the input circular waveguide 1 is enhanced, thereby allowing the use of a larger cross-section circular waveguide and further improving power capacity.
[0013] The stepped transition 5 connects the exit of the coupled wide waveguide 3 and the entrance of the rectangular waveguide 6. It is a waveguide with a gradually changing cross-sectional size, achieving a smooth transition from the wide coupled waveguide to the standard output waveguide through a stepped change. The structural parameters of the stepped transition 5 and the position of the outer pin in the double row of pins 4 need to be adjusted in combination to achieve good impedance matching over a wide frequency range.
[0014] Rectangular waveguide 6 is a standard rectangular waveguide, serving as the output port of the power divider, outputting microwaves in TE10 mode. Preferably, it has four outputs.
[0015] Furthermore, at the connection point where the coupling wide waveguide 3 intersects with the input circular waveguide 1, a rounded or chamfered structure is provided. The profile of the sloping short-circuit wall 2 is also sloping, and it maintains a specific distance from the edges of adjacent rounded corners. These rounded corners and sloping structures work together to regulate and homogenize the electric field distribution inside the power divider, avoiding local electric field concentration caused by sharp corners or abrupt structural changes, thereby preventing the power capacity from decreasing due to a reduction in the breakdown threshold.
[0016] (III) Beneficial Effects Compared with the prior art, the present invention has the following beneficial effects: 1. This invention, by employing a wide-coupled waveguide structure with built-in double-row pins, effectively increases the mode conversion channel through electrical partitioning without increasing the number of physical output ports. This effectively suppresses the competition between high-order modes in the wide waveguide and angular asymmetric modes in the circular waveguide, providing a new approach to solving the contradiction between bandwidth and power capacity in power dividers with few ports.
[0017] 2. This invention achieves broadband and efficient matching from wide-coupled waveguide to standard output waveguide by comprehensively optimizing the stepped transition parameters and the position of adjustable pins, significantly expanding the operating bandwidth of the power divider.
[0018] 3. The present invention extensively employs rounded corners and beveled surfaces in key connection parts to actively homogenize the internal electromagnetic field, significantly reducing the maximum field strength, thereby obtaining a higher theoretical power capacity based on the breakdown field strength threshold.
[0019] 4. The present invention has a compact structure, is composed entirely of waveguide components, and contains no dielectric material, making it suitable for long-term reliable operation in high-power environments. Attached Figure Description
[0020] Figure 1 The schematic diagram and electric field distribution of the S-band overmode coaxial waveguide to two rectangular waveguides power divider and including circular waveguide conversion described in Background Art 1 are shown below. Figure 2 The schematic diagram and electric field distribution of the X-band circular waveguide to 4-way rectangular waveguide power divider structure described in Background Art 2 are shown below. Figure 3 This is a schematic diagram of a power divider in a specific embodiment of the present invention; in the figure, 1 is an input circular waveguide, 2 is a sloping short-circuit wall, 3 is a coupling wide waveguide, 4 is a double row of pins, 5 is a stepped transition, and 6 is a rectangular waveguide; Figure 4 The diagram shows the internal electric field distribution and S-parameter curves of the power divider in a specific embodiment of the present invention. Detailed Implementation
[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.
[0022] A preferred embodiment of the present invention is a four-way power divider operating in the X-band. For example... Figure 3 As shown, the power divider mainly consists of an input circular waveguide 1, a sloping short-circuit wall 2, a coupling wide waveguide 3, a double row of pins 4, a stepped transition 5, and four BJ84 standard rectangular waveguides 6.
[0023] The key structural parameters of this embodiment were optimized using electromagnetic simulation software. The optimized main dimensions are as follows: the radius Ri of the input circular waveguide 1 is 21.5 mm; in the double-row pins 4, the radial position Rr of the inner pin is 42.5 mm, and the distance dr between the inner and outer pins is 5.5 mm; the width a1 of the coupled wide waveguide 3 is 51.5 mm; the width a2 of the stepped transition 5 is 40.2 mm; the radial length Ra of the coupled wide waveguide 3 is 67.4 mm; the height ha of the stepped transition 5 is 10.1 mm; the radius Rc of the inclined short-circuit wall 2 is 15.2 mm, and the depth hc is 9.7 mm; the radii R1, R2, and R3 of the three rounded corners at the connection between the coupled wide waveguide 3 and the circular waveguide 1 are 12.8 mm, 8.9 mm, and 14.0 mm, respectively; the distance hs between the end face of the inclined short-circuit wall 2 and the edge of the nearest rounded corner R1 is 2.7 mm. The diameter of the double-row pin 4 is set to 2.5mm, and the position of the outer pin can be finely adjusted during optimization.
[0024] The performance of the power divider under these parameters was verified through simulation. Figure 4 The left side shows the electric field amplitude distribution inside the power divider. It can be seen that the electric field is evenly distributed inside the structure, and there is no abnormal concentration around the rounded corners, bevels and pins. Figure 4 The S21 parameter curve on the right shows that, within the X-band, the relative bandwidth with a power transmission efficiency (conversion efficiency) greater than 99% reaches 19.7%. Based on the field strength distribution obtained from the simulation, and calculated according to the Kilpatrick criterion (with a breakdown field strength threshold of 750 kV / cm), the main structure power capacity of this power divider is greater than 4 GW.
[0025] The working principle is as follows: TM 01 The microwave mode is injected from the input circular waveguide 1. Upon encountering the inclined short-circuit wall 2, mode conversion and matching occur, and the energy enters the coupling wide waveguide 3. The presence of the double-row pins 4 suppresses higher-order modes in the wide waveguide 3 and distributes the energy more evenly. Subsequently, the microwave passes through the stepped transition 5, whose impedance is broadbandly matched with the four-way output rectangular waveguide 6, ultimately delivering a TE output. 10 The modes are output from four rectangular waveguides with equal amplitude and in-phase output. Mode competition is effectively suppressed and the electric field distribution is optimized throughout the process, thus achieving both broadband and high power capacity.
[0026] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Those skilled in the art can make various modifications and improvements without departing from the spirit and scope of the present invention.
Claims
1. A wide-waveguide coupled broadband high-power capacity power divider, characterized in that, It includes an input circular waveguide 1, a sloping short-circuit wall 2, a coupling wide waveguide 3, a double row of pins 4, a stepped transition 5, and a rectangular waveguide 6; The input circular waveguide 1 is used for inputting TM. 01 Mode microwave; The inclined short-circuit wall 2 is located at the end of the input circular waveguide 1 to realize TM. 01 Mode to TE 10 Pattern matching and transformation; The coupled wide waveguide 3 is a wide rectangular waveguide, and its entrance is connected to the input circular waveguide 1 and the inclined short-circuit wall 2; The double row of pins 4 are disposed inside the coupled wide waveguide 3, which effectively divides the coupled wide waveguide 3 into multiple narrow waveguide channels in the width direction, and is used to suppress higher-order modes in the wide waveguide and angular asymmetric modes in the input circular waveguide 1. The stepped transition 5 is connected between the outlet of the coupled wide waveguide 3 and the inlet of the rectangular waveguide 6 to achieve broadband impedance matching from the wide waveguide to the standard rectangular waveguide. The rectangular waveguide 6 is used for outputting TE. 10 Mode microwave.
2. The wide waveguide-coupled broadband high-power capacity power divider according to claim 1, characterized in that, The double-row pins 4 include two rows of metal pins arranged along the waveguide propagation direction, and the number of pins in each row corresponds to the number of paths in the output rectangular waveguide 6.
3. The wide waveguide-coupled broadband high-power capacity power divider according to claim 2, characterized in that, The position of the outer pin in the double row of pins 4 is adjustable, and its position can be adjusted to optimize the matching performance over a wide bandwidth.
4. The wide waveguide-coupled broadband high-power capacity power divider according to claim 1, characterized in that, The connection between the coupled wide waveguide 3 and the input circular waveguide 1 is provided with a rounded or chamfered corner structure.
5. The wide waveguide-coupled broadband high-power capacity power divider according to claim 4, characterized in that, The rounded corner structure includes multiple rounded corners of different radii, which are used to homogenize the electric field distribution in the connection area and reduce electric field concentration.
6. The wide waveguide-coupled broadband high-power capacity power divider according to claim 1, characterized in that, The end face of the inclined short-circuit wall 2 is inclined, and it maintains a certain distance from the adjacent rounded corner edge.
7. The wide waveguide-coupled broadband high-power capacity power divider according to claim 1, characterized in that, The stepped transition 5 is a waveguide segment with a stepped height or width. Its structural parameters are adjusted together with the position of the outer pin to achieve broadband matching.
8. The wide waveguide-coupled broadband high-power capacity power divider according to any one of claims 1 to 7, characterized in that, The rectangular waveguide 6 is a four-way standard BJ84 rectangular waveguide.
9. The wide waveguide-coupled broadband high-power capacity power divider according to any one of claims 1 to 7, characterized in that, The power divider operates in the X-band, with a relative bandwidth of 19.7% and a power conversion efficiency greater than 99%.
10. The wide waveguide-coupled broadband high-power capacity power divider according to any one of claims 1 to 7, characterized in that, The main structure of the power divider has a power capacity greater than 4GW.