High-power-capacity power divider based on mixed mode
By introducing the TM0n hybrid mode and the coaxial waveguide inner conductor groove structure, the problems of insufficient power capacity and electric field concentration in high-frequency applications of power dividers are solved, achieving efficient conversion and miniaturized design.
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
When existing power dividers are developed towards higher frequencies, they face problems such as insufficient power capacity due to the small size of the main structure and increased risk of breakdown due to the concentration of electric field at the end face of the coaxial inner conductor.
The TM0n hybrid mode is used as an intermediate conversion stage, and a groove structure is designed on the inner conductor end face of the coaxial waveguide to change the field distribution and control the power ratio and phase difference of the hybrid mode to achieve efficient conversion.
It significantly improves power capacity, reduces electric field peak, avoids breakdown risk, and maintains device miniaturization and high conversion efficiency.
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Figure CN121748752A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of high-power microwave technology, in particular to a waveguide device for high-power microwave signal distribution or synthesis, and more particularly to a high-power capacity power divider based on circular waveguide TM0n hybrid mode excitation and conversion. BACKGROUND
[0002] Power dividers and combiners are key devices commonly used in the field of high-power microwave, which are used to distribute microwave signals in multiple ways to meet the feeding requirements, or to combine multiple microwave signals to increase the output power. The power divider / combiner based on radial line structure can realize power distribution and synthesis between circular waveguide TM01 mode and multiple rectangular waveguide TE10 mode, has the advantages of short axial length and high power capacity, and is widely used in the field of high-power microwave. When TM01 mode is injected from the circular waveguide, TE10 mode with equal amplitude and phase can be output from the multiple rectangular waveguides; when TE10 mode with equal amplitude and phase is injected from the multiple rectangular waveguides, TM01 mode can be output from the circular waveguide, so this kind of device has both power distribution and synthesis functions.
[0003] In the field of high-power microwave, power dividers and combiners need to have high power capacity. With the increase of operating frequency, the transverse size of the power divider / combiner will be correspondingly reduced, which directly leads to the limitation of power capacity. At present, increasing the number of branches of rectangular waveguide, adopting overmoded structure or introducing coaxial waveguide structure are common means to improve the power capacity of power divider / combiner. However, in practical applications, considering the needs of the back-end microwave transmission and antenna system, even if a coaxial structure with relatively high power capacity is used, it is still necessary to convert the TEM mode of the coaxial waveguide into the TM01 mode of the circular waveguide, which puts higher requirements on the structure design and performance optimization of the device.
[0004] For example, Hu Xianggang et al. (Ku-band high-power overmoded circular waveguide to 8-way rectangular waveguide power divider [J], High Power Laser and Particle Beams, 2024, 36(12)) discloses a Ku-band overmoded circular waveguide to rectangular waveguide power divider, as shown in Figure 1 , the mode conversion is realized by matching waveguide cavity, which improves the power capacity, but the strong axial electric field concentration at the terminal short-circuit surface and the small size of the matching waveguide cavity limit the further improvement of the power capacity. Li Xiaomeng et al. (Research on high-power overmoded waveguide power transmission and distribution technology [D]. Chengdu: Southwest Jiaotong University, 2018.) studies an X-band power division structure with a coaxial inner conductor, as shown in Figure 2 , an overmoded circular waveguide and a rectangular waveguide are used, but there is a strong electric field at the end face of the coaxial inner conductor, and to avoid high-order mode excitation, the waveguide cross section cannot be too large, especially at higher frequencies, the power capacity decreases significantly.
[0005] In summary, the existing power divider generally faces the dual problems of insufficient power capacity due to size limitation of the main structure and increased risk of local breakdown caused by electric field concentration on the end face of the coaxial inner conductor when developing to high frequency. Therefore, there is an urgent need for a new structure that can effectively improve the power capacity. SUMMARY
[0006] (I) Technical problems to be solved The present application aims to solve the technical problems of insufficient power capacity of the main structure caused by small cross-sectional size and power capacity decline caused by electric field concentration on the end face of the coaxial inner conductor when the existing power divider develops to high frequency application, and further provides a power divider with high power capacity, low surface electric field and high conversion efficiency.
[0007] (II) Technical solutions To solve the above problems, the present application proposes a high power capacity power divider based on hybrid mode. The core idea of the present application is to introduce TM0n hybrid mode as an intermediate conversion link and skillfully design the end face structure of the inner conductor, so as to allow the use of larger cross-section waveguide to improve the power capacity of the main body, while effectively suppressing the electric field intensity of the key parts.
[0008] The technical solutions of the present application are as follows: A high power capacity power divider based on hybrid mode, comprising input circular waveguide 1, bevel transition section 2, large-mode-ratio circular waveguide 3, coaxial waveguide 4, radial line 5 and multiple rectangular waveguides 6 connected in sequence along the microwave transmission direction, as shown in Figure 3 .
[0009] The input circular waveguide 1 is used to inject TM01 mode microwave signal.
[0010] The bevel transition section 2 is connected to the end of the input circular waveguide 1, with a length of Lt, which functions to achieve a smooth transition from the input waveguide to the large-mode-ratio circular waveguide 3, and excite high-order hybrid modes in the process.
[0011] The large-mode-ratio circular waveguide 3 is connected to the end of the bevel transition section 2, with a length of Lb and a radius Rb greater than 0.88 times the working wavelength, to ensure that it can support and transmit at least TM 01 mode hybrid modes including TM 02 mode excited by TM 0n mode.
[0012] Coaxial waveguide 4 is connected to the end of large overmoded circular waveguide 3. The inner conductor length Lc of the coaxial waveguide 4, the inner-outer conductor gap Rc; its inner conductor end face is not flat, but is provided with a groove structure. This groove structure has multiple functions: first, by changing the end face geometry, the concentrated axial electric field at the center of the end face is dispersed and reduced, solving the strong field problem there; second, by adjusting the radius Rh and depth Lh of the groove, the power ratio of each TM 0n mixed mode (such as TM 01 , TM 02 ) transmitted in the front-stage large overmoded circular waveguide 3 and the relative phase difference between them can be controlled, so as to optimize and realize efficient conversion from the TM 0n mixed mode of the circular waveguide to the fundamental mode TEM mode of the coaxial waveguide.
[0013] Radial line 5 is connected to the end of coaxial waveguide 4, with a radius of Rr, for receiving the converted TEM mode power and distributing it uniformly to each output branch.
[0014] Multiple rectangular waveguides 6 are uniformly connected to the outer periphery of radial line 5 for outputting the distributed power in TE10 mode.
[0015] In addition, the radius Rin of the input circular waveguide 1 and the radius Rh of the groove at the end face of the inner conductor of the coaxial waveguide 4 need to be less than 0.88 times the working wavelength, so as to suppress the excitation and transmission of TM 02 and above modes in this area, ensuring mode purity. The depth Lh of the groove should be less than 0.5 times the working wavelength to ensure that the electric field inside the groove is effectively suppressed. The connection between radial line 5 and coaxial waveguide 4 is usually designed with first chamfer R1 and second chamfer R2 to improve matching, and third chamfer R3 and fourth chamfer R4 can be provided at the outer wall of the groove to further optimize the electric field distribution.
[0016] (Three) beneficial effects Compared with the prior art, the present application has the following beneficial effects: 1. By adopting TM0n mixed mode as the conversion intermediate state, the present application breaks the strict restriction on single mode matching, so that a large overmoded circular waveguide 3 and a coaxial waveguide 4 with larger cross-sectional size can be used, thereby significantly improving the power capacity of the main structure of the power divider.
[0017] 2. By introducing a specific groove structure at the end face of the inner conductor of the coaxial waveguide 4, the field distribution at this key position is fundamentally changed, the concentrated axial electric field is dispersed, and the electric field peak at this key position is effectively reduced, thereby avoiding the power capacity reduction and breakdown risk caused thereby.
[0018] 3. In the present application, the groove structure is not only used for field intensity control, but also is the key freedom degree for adjusting the mixed mode component and phase. By optimizing these parameters, high efficiency and wide bandwidth conversion from mixed mode to TEM mode can be realized, and the overall performance of the device is improved.
[0019] 4. The structure of the present application is compact, and high power capacity is realized while maintaining a small axial size. For example, a design with a length of less than 10 cm can be realized in the Ku band, combining high performance and miniaturization. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 For the structure diagram and electric field distribution of the Ku-band overmoded circular waveguide to rectangular waveguide power divider in the background art; Figure 2 For the structure diagram and electric field distribution of the X-band power divider with coaxial inner conductor in the background art; Figure 3 For the structure diagram of the power divider in the embodiment of the present application; in the figure, circular waveguide 1, inclined surface transition section 2, large overmoded circular waveguide 3, coaxial waveguide 4, radial line 5 and 16 rectangular waveguides 6; Figure 4 For the internal electric field distribution of the power divider in the embodiment of the present application. DETAILED DESCRIPTION
[0021] The present application will be further described in detail below in combination with the drawings and specific embodiments. The embodiment takes a power divider with a working frequency of 14.3 GHz (Ku band) as an example, and the output is 16 standard BJ120 rectangular waveguides.
[0022] Referring to Figure 3 , the power divider of the embodiment of the present application includes input circular waveguide 1, inclined surface transition section 2, large overmoded circular waveguide 3, coaxial waveguide 4, radial line 5 and 16 rectangular waveguides 6. Microwave is injected from the input circular waveguide 1 in TM01 mode.
[0023] The key structural parameters of the embodiment are determined through electromagnetic simulation optimization as follows: the input circular waveguide radius Rin is 15 mm; the inclined surface transition section length Lt is 30 mm; the large overmoded circular waveguide radius Rb is 27.7 mm, and the length Lb is 16.2 mm; the inner conductor length Lc of the coaxial waveguide is 26.3 mm, and the inner and outer conductor gap Rc is 9.0 mm; the inner conductor end face groove radius Rh is 13.4 mm, and the depth Lh is 5.0 mm; the radial line radius Rr is 53.0 mm; the first chamfer R1 at the connection of the radial line and the coaxial waveguide is 10 mm, and the second chamfer R2 is 19 mm; the third chamfer R3 and the fourth chamfer R4 at the outer wall of the groove are both 2.6 mm. The overall length of the power divider is less than 10 cm.
[0024] Under these parameters, the input circular waveguide radius Rin (15mm) and the groove radius Rh (13.4mm) are both less than 0.88 times the wavelength (about 18.5mm), effectively suppressing the high-order modes in this region. The large-mode-ratio circular waveguide radius Rb (27.7mm) is greater than 0.88 times the wavelength, which can support TM01 and TM02 mode transmission, and is close to the critical cutoff for TM03 mode, making the hybrid mode dominated by TM01 and TM02, which is convenient for efficient conversion. The groove depth Lh (5.0mm) is less than 0.5 times the wavelength (about 10.5mm), effectively controlling the internal field strength.
[0025] The working principle of the structure is: after the TM01 mode microwave passes through the inclined transition section 2, the mixed mode dominated by TM01 and TM02 is excited in the large-mode-ratio circular waveguide 3. These mixed modes propagate to the open end of the coaxial waveguide 4, and through the field matching and adjusting effect of the end face groove structure, they are efficiently converted into the TEM mode of the coaxial waveguide. The converted power enters the radial line 5 for uniform distribution, and finally is output in the TE10 mode with equal amplitude and in phase by 16 rectangular waveguides 6.
[0026] The simulation results show that the highest mode conversion efficiency of the power divider in this embodiment is more than 99%, and the relative bandwidth with a conversion efficiency greater than 95% is about 10%. Figure 4 The internal electric field distribution when injecting 5GW microwave power is shown, and it can be seen that the maximum surface electric field strength is about 800kV / cm, which is significantly lower than the breakdown threshold (about 970kV / cm) estimated according to the Kilpatrick criterion, especially the electric field in the end face groove area of the coaxial inner conductor is obviously suppressed. This fully verifies the excellent effect of the present application in improving the power capacity and controlling the surface electric field.
[0027] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it. Those skilled in the art can modify or equivalently replace the structure and parameters without departing from the spirit and scope of the present application, and these modifications or replacements should also be considered to fall within the protection scope of the present application.
Claims
1. A high-power capacity power divider based on hybrid mode, characterized in that, It includes an input circular waveguide (1), a sloped transition section (2), a high overmodulus circular waveguide (3), a coaxial waveguide (4), a radial line (5), and multiple rectangular waveguides (6) connected sequentially along the microwave transmission direction. The input circular waveguide (1) is used to inject TM01 mode microwaves; The inclined transition section (2) connects the input circular waveguide (1) and the high overmode ratio circular waveguide (3) to achieve mode conversion; The radius of the high overmode ratio circular waveguide (3) is greater than 0.88 times the operating wavelength, and it is used to support and transmit TM. 01 TM generated by pattern incentives 0n Mixed mode, where n≥2; The coaxial waveguide (4) is connected to the end of the large overmode ratio circular waveguide (3). The inner conductor end face is provided with a groove structure to reduce the concentration of the axial electric field on the end face and adjust the power ratio and phase difference of the hybrid mode, so as to realize the efficient conversion of the TM0n hybrid mode to the coaxial waveguide TEM mode. The radial line (5) connects the coaxial waveguide (4) and each rectangular waveguide (6) to distribute the TEM mode power to each output branch; The plurality of rectangular waveguides (6) are used to output TE10 mode microwaves.
2. The high-power capacity power divider based on hybrid mode according to claim 1, characterized in that, The radius of the input circular waveguide (1) and the radius of the groove on the inner conductor end face of the coaxial waveguide (4) are both less than 0.88 times the working wavelength, so as to cut off TM02 and higher order modes.
3. The high-power capacity power divider based on hybrid mode according to claim 1, characterized in that, The depth of the groove on the inner conductor end face of the coaxial waveguide (4) is less than 0.5 times the working wavelength.
4. The high-power capacity power divider based on hybrid mode according to claim 1, characterized in that, The groove structure, through the design of its radius and depth, can control the TM in the high overmode ratio circular waveguide (3). 0n The power ratio and phase relationship of the hybrid mode.
5. The high-power capacity power divider based on hybrid mode according to claim 1, characterized in that, The radius of the high overmodulus circular waveguide (3) is specifically set to support TM. 02 Mode transmission, and for TM 03 Ideally, the mode should be close to the critical cutoff state.
6. The high-power capacity power divider based on hybrid mode according to claim 1, characterized in that, The connection between the radial line (5) and the coaxial waveguide (4) is provided with a first chamfer (R1) and a second chamfer (R2).
7. The high-power capacity power divider based on hybrid mode according to claim 1, characterized in that, The outer wall of the groove structure is provided with a third chamfer (R3) and a fourth chamfer (R4).
8. The high-power capacity power divider based on hybrid mode according to any one of claims 1 to 7, characterized in that, The rectangular waveguide (6) has 16 channels.
9. The high-power capacity power divider based on hybrid mode according to any one of claims 1 to 7, characterized in that, The overall length of the power divider is less than 10 centimeters.
10. The high-power capacity power divider based on hybrid mode according to any one of claims 1 to 7, characterized in that, The power divider operates in the Ku band with a center frequency of 14.3 GHz.