Compact broadband circular waveguide TM01 mode bending structure

Abstract

The invention discloses a compact broadband circular waveguide TM01 mode bending structure, and aims to solve the technical bottleneck that an existing circular waveguide TM01 mode bending structure is difficult to consider the aspects of bandwidth, structural compactness and power capacity at the same time. The antenna is composed of two circular waveguide TM01 mode power dividers, two E-plane U-shaped folded waveguide arrays and two E-plane rectangular bent waveguide arrays. The coaxial waveguide TEM mode and the multi-path rectangular waveguide TE10 mode are adopted as the middle transition mode of the antenna, and the problem of mode competition in a traditional bending structure is effectively solved. Meanwhile, by utilizing an E-plane U-shaped folded waveguide phase compensation technology, the length of each rectangular waveguide transmission path between the two circular waveguide TM01 mode power dividers is ensured to be consistent, the relative working bandwidth of which the transmission efficiency of a bent structure is greater than 95% is widened to be more than 40%, the power capacity is improved to the GW magnitude, and the distance between input / output ports is shortened to be within 5 times of the central wavelength.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-power microwave transmission technology, and particularly provides a circular waveguide TM 01 mode bending structure. BACKGROUND

[0002] High-power microwave (HPM) is a kind of strong electromagnetic pulse with high peak power, high repetition frequency and short pulse characteristics, which has important application value in the fields of industry, civil and especially military. In recent years, with the rapid development of HPM technology engineering application, the miniaturization, compactness, frequency agility and bandwidth expansion technology of HPM system have become the focus of current HPM field research. At present, most high-power microwave sources, such as backward wave oscillator (BWO) and magnetically insulated line oscillator (MILO), generally adopt circular waveguide TM 01 mode as the output mode. In the HPM system, the microwave source and the antenna transmitting system are usually located at the lower part and the upper part of the HPM system respectively. In order to realize the reasonable layout of the system, the waveguide devices such as waveguide bending structure and waveguide axial adjustment structure are usually used to connect between the microwave source and the antenna transmitting system. The transmission characteristics of these waveguide devices will directly affect the performance indicators of the whole HPM system. Therefore, it is of great value to design a circular waveguide TM 01 mode bending structure with wide working frequency band, compact structure and high conversion efficiency for the engineering design and application of HPM system.

[0003] In the circular waveguide TM 01 mode bending structure, the input and output ports are both overmoded circular waveguides. If the bending circular waveguide is directly used for bending, TE 11 and TE 21 parasitic modes will be excited in the process of bending the circular waveguide. These parasitic modes will compete with the input TM 01 mode, resulting in the reduction of the transmission efficiency of the bending structure. In view of this problem, Yuanchengwei of National University of Defense Technology and others optimized the curvature radius of the bending circular waveguide by calculating the mode coupling coefficients under different curvature radii of the bending circular waveguide based on the mode coupling theory [Yuanchengwei, Zhong Huihuang, Qian Baoliang. Design of high-power microwave bending circular waveguide [J]. High Power Laser and Particle Beams, 2009, 21(2): 255-259]. And a circular waveguide TM 01A curved structure was proposed. Although this curved structure achieved a transmission efficiency of 99.7% at the center frequency, it suffered from limitations such as a large bending radius of the circular waveguide (the spacing between the input / output ports is 17.7 times the center wavelength) and a narrow operating bandwidth (the relative operating bandwidth for transmission efficiencies greater than 95% is only 20.0%). To further expand the operating bandwidth and improve structural compactness, Keqiang Wang et al. from the University of Electronic Science and Technology of China proposed a novel curved structure based on a variable curvature elliptical waveguide [Keqiang Wang, Zhiqiang Zhang, Hao Li, et al. Design of a BroadBandwidth™]. 01 Mode Waveguide Bend for High-Power Microwave Applications[J]. IEEE Transactions on Microwave Theory and Techniques, 2023, 71(10): 1-8]. This structure employs an elliptical waveguide™. 01 As an intermediate transition mode, the elliptical waveguide TM was realized by optimizing the bending curvature distribution of the elliptical waveguide. 01 Broadband transmission of the mode is achieved by connecting a circular waveguide-elliptical waveguide transition structure to each end of the variable curvature elliptical waveguide, thus realizing a circular waveguide™ 01 Modes and Elliptical Waveguides™ 01 Efficient mode conversion between modes. Simulation results show that the structure achieves a relative operating bandwidth of 45.36% (transmission efficiency >95%) at a center frequency of 9.7 GHz. However, this design has three shortcomings: First, because the elliptical waveguide aperture is smaller than that of the circular waveguide, a significant electric field enhancement effect occurs during bending. This results in a maximum electric field strength of 1521 V / m within the cavity under an input microwave power of 0.5 W. Based on the electric field breakdown threshold of 700 kV / cm under vacuum conditions, the calculated power capacity of this bent structure under vacuum conditions is limited to approximately 1.1 GW. Second, to achieve broadband transmission characteristics, the circular waveguide-elliptical waveguide transition structure requires a relatively long physical dimension, making the spacing between the input / output ports of the entire bent structure 11.9 times the center wavelength. Third, the variable curvature elliptical waveguide has complex curvature variation characteristics, thus requiring high design complexity and fabrication precision. Li Xiaomeng et al. from Southwest Jiaotong University proposed a coaxial insert-type circular waveguide™. 01 Mode-Bending Structure [Xiaomeng Li, Xiangqing Li, Qingxiang Liu, et al. High Power Over-Mode 90° Bent Waveguides for CircularTM]01 [and Coaxial TEM Mode Transmission[J]. Progress In Electromagnetics Research M, 2017, 60: 189-196], this bent structure uses a coaxial waveguide for bending. By uniformly inserting four metal partitions along the angular direction of the bent coaxial waveguide, the coaxial waveguide TEM mode is converted into four equal-amplitude fan-shaped waveguide TE modes. 11 The model is then optimized by adjusting the radius of curvature of the curved coaxial waveguide to ensure that the path difference between the inner and outer fan-shaped waveguides is an integer multiple of its transmission wavelength, thereby achieving a 4-channel fan-shaped waveguide TE at the output of the curved coaxial waveguide. 11 The modes were resynthesized into a coaxial waveguide TEM mode. A circular waveguide TM designed using this method was then created. 01 The curved structure offers the advantage of high compactness. Simulation results show that for a curved structure with a center frequency of 8.4 GHz, the input / output port spacing can be controlled within 1.5 times the center wavelength, while the power capacity can reach 2.4 GW under vacuum conditions. However, the operating bandwidth of this curved structure is relatively narrow; even with a transmission efficiency greater than 95%, the relative operating bandwidth is only 3.6%.

[0004] Therefore, how to significantly extend the circular waveguide™ while ensuring structural compactness and high power capacity? 01 The operating bandwidth of modal bending structures has become a key technical challenge that urgently needs to be overcome in this field. Summary of the Invention

[0005] The technical problem to be solved by this invention is that it addresses the limitations of existing circular waveguides (TM). 01 Overcoming the technical bottleneck of balancing wide operating bandwidth, compact structure, and high power capacity in mode-bent structures, this paper presents a compact broadband circular waveguide™ with a relative operating bandwidth exceeding 40%, a power capacity exceeding GW under vacuum conditions, and an input / output port spacing of less than 5 times the center wavelength. 01 Pattern bending structure.

[0006] The technical solution of this invention is: This invention is a compact broadband circular waveguide™ 01 The mode bending structure consists of two circular waveguides TM 01 Mode power divider (i.e., first circular waveguide™) 01 Mode power divider and second circular waveguide™ 01The whole curved structure is composed of a mode power divider, two E-plane U-shaped folded waveguide arrays (i.e. a first E-plane U-shaped folded waveguide array and a second E-plane U-shaped folded waveguide array), and two E-plane rectangular bent waveguide arrays (i.e. a first E-plane rectangular bent waveguide array and a second E-plane rectangular bent waveguide array). Each component of the whole curved structure is made of metal material (preferably aluminum alloy). The circular waveguide port of the mode power divider is the input end of the present application. 01 The circular waveguide port of the mode power divider is the output end of the present application. 01 The circular waveguide port of the mode power divider is the output end of the present application.

[0007] The circular waveguide port of the mode power divider is the output end of the present application. 01 The mode power divider is composed of an input circular waveguide, a first circular waveguide, a first frustum matching structure, a first rectangular transition waveguide circumferential array, a first rectangular waveguide circumferential array, and a first H-plane bent waveguide array. The circular waveguide port of the mode power divider is the input end of the present application. 01 The mode power divider is respectively mirror symmetrical along the AA 'plane and the BB 'plane. The upper end of the input circular waveguide is the input end of the present application. The input circular waveguide is a cylinder with a radius of r 0 and a length of l 0. In order to facilitate the connection with other waveguide components in the HPM transmission system, the radius r 0 of the input circular waveguide is equal to the actual radius of the connected external circular waveguide. The upper end of the input circular waveguide is used to receive the externally input circular waveguide TM 01 mode microwave, and the lower end is connected to the upper end of the first circular waveguide. The first circular waveguide is a cylinder with a radius of r 1 and a height of b 0, and r 1> r 0>0. Since there is a discontinuous area at the connection between the upper end of the first circular waveguide and the lower end of the input circular waveguide, the local electric field will be enhanced when the microwave is transmitted to this area, thereby reducing the power capacity of the whole curved structure. In order to improve the power capacity, a fillet treatment is adopted at this connection, and the fillet radius is e 1. The side surface circumferential area of the first circular waveguide is sequentially connected to N rectangular transition waveguides (N≥4, and N is an even number) in the first rectangular transition waveguide circumferential array.

[0008] To realize the high-efficiency transmission of microwave energy to the circumferential array of the first rectangular transition waveguide, a first conical frustum matching structure is embedded in the bottom of the first circular waveguide. The top of the first conical frustum matching structure extends into the input circular waveguide, and the bottom is in the same plane as the bottom of the first circular waveguide. The first conical frustum matching structure, the input circular waveguide and the first circular waveguide are all centrally symmetric along the central axis OO'. The first conical frustum matching structure is cascaded from top to bottom by three layers of impedance matching structures: the upper layer is a circular frustum impedance matching structure, the middle layer is a cylindrical impedance matching structure, and the lower layer is an arc-shaped circular frustum impedance matching structure. The top cross-sectional radius of the circular frustum impedance matching structure is r 2, the bottom cross-sectional radius is r 3, the height is h 1, and r 0> r 3> r 2>0. To suppress the local electric field enhancement at the discontinuity at the periphery of the top cross-section of the circular frustum impedance matching structure, the periphery of the top cross-section of the circular frustum impedance matching structure is rounded with a radius of e 2. The lower end of the circular frustum impedance matching structure is connected to the upper end of the cylindrical impedance matching structure. The cross-sectional radius of the cylindrical impedance matching structure is equal to r 3, and the height is h 2. The upper end of the cylindrical impedance matching structure is connected to the lower end of the circular frustum impedance matching structure. The same rounding treatment is also applied to the discontinuity at the connection between the upper end of the cylindrical impedance matching structure and the lower end of the circular frustum impedance matching structure, with a radius of e 3. The lower end of the cylindrical impedance matching structure is connected to the upper end of the arc-shaped circular frustum impedance matching structure. The arc-shaped circular frustum impedance matching structure is formed by rounding the bottom of the cylindrical structure with a cross-sectional radius of r 3 and a height of h 3, where the rounding radius is e 4, and h 3= e 4. The main function of the circular frustum impedance matching structure and the cylindrical impedance matching structure is to efficiently convert the TM 01 mode of the input circular waveguide into a coaxial waveguide TEM mode. Subsequently, the arc-shaped circular frustum impedance matching structure converts the coaxial waveguide TEM mode into N rectangular waveguide TE 10 modes, and inputs the N rectangular waveguide TE 10 modes into the N rectangular transition waveguides in the circumferential array of the first rectangular transition waveguide.

[0009] The circumferential array of the first rectangular transition waveguide is composed of N structurally identical rectangular transition waveguides arranged uniformly along the central axis OO'. These N rectangular transition waveguides have the same size, with the wide side length of the inner cross-section (close to the central axis OO') being a 1, and the narrow side length being equal to b0, the width of the outer (away from the central axis OO') cross-section is a 0, the length of the narrow side is equal to b 0, and a 1> a 0, the distance between the inner and outer cross sections is l 1, a 1=2 r 1×sin(180° / N). The inner end faces of each rectangular transition waveguide in the first rectangular transition waveguide circular array are sequentially connected to the outer surface of the first circular waveguide, and the outer end faces are connected to the inner end faces of N first rectangular waveguides in the first rectangular waveguide circular array. The main function of the first rectangular transition waveguide circular array is to reduce the microwave input to the TE of each rectangular waveguide in the first rectangular waveguide circular array. 10 The reflection of the pattern improves microwave transmission efficiency. The first rectangular waveguide circular array consists of N identical first rectangular waveguides, which are uniformly arranged in a circle along the central axis OO'. These N first rectangular waveguides have the same dimensions, and the width of their cross-section is equal to... a 0, the length of the narrow side is equal to b 0, length is l 2. Both the first rectangular waveguide circular array and the first rectangular waveguide circular array are along... AA 'Planar mirror symmetry, and also along BB 'Planar mirror symmetry. The inner end faces of the N first rectangular waveguides in the first rectangular waveguide circular array are respectively connected to the outer end faces of the N rectangular transition waveguides in the first rectangular transition waveguide circular array, and the inner end face of the kth first rectangular waveguide is connected to the outer end face of the kth rectangular transition waveguide. The outer end faces of the N first rectangular waveguides in the first rectangular waveguide circular array are respectively connected to the inner end faces of the N first H-plane curved waveguides in the first H-plane curved waveguide array, and the outer end face of the kth first rectangular waveguide is connected to the inner end face of the kth first H-plane curved waveguide.'

[0010] The first H-plane curved waveguide array consists of N first H-plane curved waveguides. This array is along... AA 'Planar mirror symmetry, also along BB 'Planar mirror symmetry. The inner end face of each of the first H-plane curved waveguides in the first H-plane waveguide array is connected to the outer end face of each of the N first rectangular waveguides in the first rectangular waveguide circular array. The inner end face of the k-th first H-plane curved waveguide is connected to the outer end face of the k-th first rectangular waveguide. The cross-sectional width of each of the N first H-plane curved waveguides in the first H-plane waveguide array is equal to...' a 0, the length of the narrow side is equal to b 0, bending radius is 0 e r ,and e r > a0 / 2. The bending angle of the k-th first H-plane curved waveguide among N first H-plane curved waveguides. Calculated using formula (1) or formula (2): When n is even : (1) when When it is an odd number: (2).

[0011] After the N first H-plane folded waveguides of the first H-plane folded waveguide array are folded according to the bending angle calculated by formula (1) or formula (2), their outer end faces will all be parallel to the BB' plane. The outer end faces of the n first H-plane folded waveguides on the left side of the first H-plane folded waveguide array are respectively connected to the n second rectangular waveguide input ports of the first rectangular waveguide array of the first E-plane U-shaped folded waveguide array; the outer end faces of the n first H-plane folded waveguides on the right side of the first H-plane folded waveguide array are respectively connected to the n tenth rectangular waveguide input ports of the fourth rectangular waveguide array of the second E-plane rectangular folded waveguide array. First Circular Waveguide™ 01 The function of a mode power divider is to convert the input circular waveguide TM... 01 High-efficiency conversion of mode microwave to N-way rectangular waveguide TE 10 This transforms the complex bending problem of overmode circular waveguides into a bending problem of N-channel single-mode rectangular waveguides, fundamentally eliminating the mode competition problem present in the traditional bending process of overmode circular waveguides.

[0012] The first E-plane U-shaped folded waveguide array consists of a first rectangular waveguide array, a first E-plane U-shaped bent waveguide array, and a second rectangular waveguide array. The first rectangular waveguide array contains n parallel-arranged second rectangular waveguides. These second rectangular waveguides have the same cross-sectional dimensions (the length of the wider side is equal to...). a 0, the length of the narrow side is equal to b 0), with lengths respectively d 1, d 2,…, d k' ,…, d n , 1≤k'≤n. The n input ports of the second rectangular waveguide of the first rectangular waveguide array are respectively connected to the n output ports (outer end faces) of the first H-plane curved waveguide on the left side of the first H-plane curved waveguide array, and the output ports are respectively connected to the n input ports above the first E-plane U-shaped curved waveguide of the first E-plane U-shaped waveguide array.

[0013] The first E-plane U-shaped bend waveguide array consists of n parallel, identically structured first E-plane U-shaped bend waveguides. Taking the k'-th first E-plane U-shaped bend waveguide as an example, it is composed of a fourth rectangular waveguide, a fifth rectangular waveguide, and a sixth rectangular waveguide. The k'-th first E-plane U-shaped bend waveguide is mirror-symmetrical along the CC' plane. The right port of the fourth rectangular waveguide is the microwave input port of the k'-th first E-plane U-shaped bend waveguide, and the right port of the sixth rectangular waveguide is the microwave output port of the k'-th first E-plane U-shaped bend waveguide. The fourth and sixth rectangular waveguides have the same structural dimensions; the width of their cross-sections is equal to... a 0, the length of the narrow side is equal to b 0, all lengths are l 3, and l 3> b 0. The fifth rectangular waveguide is used to connect the fourth and sixth rectangular waveguides; the length of the wider side of its cross-section is equal to... a 0, the length of the narrow side is equal to b 0, length is H To suppress local electric field enhancement and broaden the operating bandwidth, a rounded corner is used at the junction of the fifth rectangular waveguide and the fourth rectangular waveguide above it. The inner chamfer radius is [missing information]. e 5. The outer chamfer radius is e 6, and e 6> e 5>0. Similarly, a rounded corner is also used at the junction of the fifth rectangular waveguide and the sixth rectangular waveguide below, where the inner chamfer radius is equal to... e 5. The outer chamfer radius is equal to e 6. The n input ports of the first E-plane U-shaped bend waveguide array are respectively connected to the output ports of the n second rectangular waveguides of the first rectangular waveguide array, and the output ports are respectively connected to the n third rectangular waveguide input ports of the second rectangular waveguide array.

[0014] The second rectangular waveguide array also contains n parallel third rectangular waveguides, all of which have the same cross-sectional dimensions (width equal to the length of the wider side). a 0, the length of the narrow side is equal to b 0), with lengths respectively q 1, q 2,…, q k' ,…, q n The n third rectangular waveguide input ports of the second rectangular waveguide array are respectively connected to the output ports below the n E-plane U-shaped bend waveguides of the first E-plane U-shaped bend waveguide array, and the output ports are respectively connected to the input ports of the n first rectangular bend waveguides of the first E-plane rectangular bend waveguide array.

[0015] The primary function of the first E-plane U-shaped folded waveguide array is to achieve phase compensation and bandwidth extension. This is achieved by adjusting the lengths of the rectangular waveguides in the first and second rectangular waveguide arrays, thereby extending the bandwidth of the first circular waveguide TM. 01 The left side of the mode power divider and the second circular waveguide TM 01 Each rectangular waveguide path and phase between the mode power dividers is compensated to keep their transmission path lengths consistent, thereby significantly improving the operating bandwidth of the entire curved structure.

[0016] The first E-plane rectangular curved waveguide array consists of a first rectangular curved waveguide array and a third rectangular waveguide array. The first rectangular curved waveguide array comprises n parallel, identical first rectangular curved waveguides. Taking the k'-th first rectangular curved waveguide as an example, this first rectangular curved waveguide is composed of the seventh and eighth rectangular waveguides arranged at an angle... β They are composed of inclined, staggered combinations. The seventh and eighth rectangular waveguides have the same structural dimensions, with the width of each side being equal to... a 0, the length of the narrow side is equal to b 0, all lengths are l 4, and l 4> b 0. To suppress local electric field enhancement and broaden the operating bandwidth, a rounded corner is used at the junction of the seventh and eighth rectangular waveguides, wherein the inner chamfer radius is [missing information]. e 7. The outer chamfer radius is e 8, and e 8> e 7>0. The input ports on the left side of the n first rectangular curved waveguides of the first rectangular curved waveguide array are respectively connected to the output ports of the n third rectangular waveguides of the second rectangular waveguide array. The output ports above the n first rectangular curved waveguides of the first rectangular curved waveguide array are respectively connected to the input ports below the n ninth rectangular waveguides of the third rectangular waveguide array.

[0017] The third rectangular waveguide array contains n parallel ninth rectangular waveguides, all of which have the same cross-sectional dimensions (the length of their widest side is equal to...). a 0, the length of the narrow side is equal to b 0), with lengths respectively p 1, p 2,…, p k' ,…, p n The input ports below the n ninth rectangular waveguides of the third rectangular waveguide array are respectively connected to the output ports above the n first rectangular curved waveguides of the first rectangular curved waveguide array. The output ports above the n ninth rectangular waveguides of the third rectangular waveguide array are respectively connected to the second circular waveguide TM. 01The n second H-plane curved waveguide input ports below the second H-plane curved waveguide array of the mode power divider are connected.

[0018] The second E-plane rectangular curved waveguide array consists of a fourth rectangular waveguide array and a second rectangular curved waveguide array. The fourth rectangular waveguide array contains n parallel tenth rectangular waveguides, all of which have the same cross-sectional dimensions (the length of their widest side is equal to...). a 0, the length of the narrow side is equal to b 0), with lengths respectively s 1, s 2,…, s k' ,…, s n The input ports on the left side of the n tenth rectangular waveguides of the fourth rectangular waveguide array are respectively connected to the output ports on the right side of the n first H-plane curved waveguides in the first H-plane curved waveguide array. The output ports on the right side of the n tenth rectangular waveguides of the fourth rectangular waveguide array are respectively connected to the input ports on the left side of the n second rectangular curved waveguides of the second rectangular curved waveguide array.

[0019] The second rectangular curved waveguide array has the same structural dimensions as the first rectangular curved waveguide array, and consists of n identical second rectangular curved waveguides. The left input ports of the n second rectangular curved waveguides of the second rectangular curved waveguide array are connected to the right output ports of the n tenth rectangular waveguides of the fourth rectangular waveguide array, while the upper output ports are connected to the lower input ports of the n eleventh rectangular waveguides of the fifth rectangular waveguide array of the second E-plane U-shaped folded waveguide array.

[0020] The main function of the first and second E-plane rectangular curved waveguide arrays is to realize circular waveguide™ 01 The bending function of the mode bending structure, the angle between the axial directions of the input circular waveguide and the output circular waveguide is equal to β It can be set according to the spatial layout requirements of specific engineering applications. This customizable bending characteristic at any angle can significantly improve the flexibility of microwave transmission system layout.

[0021] Similar to the first E-plane U-shaped folded waveguide array, the second E-plane U-shaped folded waveguide array consists of a fifth rectangular waveguide array, a second E-plane U-shaped bend waveguide array, and a sixth rectangular waveguide array. The fifth rectangular waveguide array contains n parallel eleventh rectangular waveguides, all of which have the same cross-sectional dimensions (width equal to...). a 0, the length of the narrow side is equal to b 0), with lengths respectively c 1, c 2,…, c k' ,…, cn The second E-plane U-shaped waveguide array consists of n parallel, identically structured second E-plane U-shaped waveguides. The structural dimensions of these n second E-plane U-shaped waveguides are identical to the k'-th first E-plane U-shaped waveguide of the first E-plane U-shaped waveguide array. The input ports below the n tenth rectangular waveguides of the fifth rectangular waveguide array are connected to the output ports above the n second rectangular waveguides of the second rectangular waveguide array. The output ports above the output ports are connected to the lower left input ports of the n second E-plane U-shaped waveguides of the second E-plane U-shaped waveguide array. The lower left input ports of the n second E-plane U-shaped waveguides of the second E-plane U-shaped waveguide array are connected to the output ports above the n eleventh rectangular waveguides of the fifth rectangular waveguide array. The lower right output ports are connected to the input ports above the n twelfth rectangular waveguides of the sixth rectangular waveguide array.

[0022] The sixth rectangular waveguide array contains n parallel twelfth rectangular waveguides, all of which have the same cross-sectional dimensions (width equal to the length of the widest side). a 0, the length of the narrow side is equal to b 0), with lengths respectively g 1, g 2,…, g k' ,…, g n In terms of structural connections, the input ports above the n twelfth rectangular waveguides of the sixth rectangular waveguide array are respectively connected to the lower right output ports of the n second E-plane U-shaped bend waveguides of the second E-plane U-shaped bend waveguide array, and the output ports below are respectively connected to the second circular waveguide TM. 01 The n second H-plane curved waveguide input ports above the second H-plane curved waveguide array of the mode power divider are connected.

[0023] Similar to the first E-plane U-shaped folded waveguide array, the second E-plane U-shaped folded waveguide array also serves to provide phase compensation and bandwidth extension. By adjusting the lengths of the rectangular waveguides in the fifth and sixth rectangular waveguide arrays, the first circular waveguide TM can be... 01 The right side of the mode power divider and the second circular waveguide TM 01 Each rectangular waveguide above the mode power divider undergoes path and phase compensation to ensure consistent transmission path lengths, thereby significantly improving the overall operating bandwidth performance of the curved structure.

[0024] Second Circular Waveguide™ 01 Mode power divider and first waveguide TM 01The mode power divider has the same structural dimensions and consists of an output circular waveguide, a second circular waveguide, a second frustum-shaped matching structure, a second rectangular transition waveguide circular array, a second rectangular waveguide circular array, and a second H-plane curved waveguide array. The n input ports of the second H-plane curved waveguide array below the second H-plane curved waveguide array are connected to the output ports above the n ninth rectangular waveguides of the third rectangular waveguide array. The n input ports of the second H-plane curved waveguide array above the second H-plane curved waveguide array are respectively connected to the output ports below the n twelfth rectangular waveguides of the sixth rectangular waveguide array. Second Circular Waveguide™ 01 The main function of the mode power divider is to convert the input N rectangular waveguide TE... 10 Efficient mode conversion to circular waveguide™ 01 Mode output.

[0025] This invention is a compact broadband circular waveguide™ 01 The working principle of the mode bending structure is: First circular waveguide TM 01 The mode power divider will input the circular waveguide TM 01 The mode is converted to an N-way rectangular waveguide TE with symmetrical left and right sides. 10 The pattern is achieved through the coordinated operation of the first E-plane U-shaped folded waveguide array, the second E-plane U-shaped folded waveguide array, the first E-plane rectangular bent waveguide array, and the second E-plane rectangular bent waveguide array, enabling bent transmission of n rectangular waveguides on both sides and connecting them to the second circular waveguide TM. 01 Mode power divider. The key is to ensure the first circular waveguide™ is maintained by adjusting the lengths of the rectangular waveguides in the first E-plane U-shaped folded waveguide array and the second E-plane U-shaped folded waveguide array. 01 Mode power divider and second circular waveguide™ 01 The microwave transmission path lengths of the N rectangular waveguides between the mode power dividers are kept consistent, ensuring that the input to the second circular waveguide TM is consistent. 01 N-channel rectangular waveguide TE mode power divider 10 The modes can be resynthesized into circular waveguide TM. 01 Mode output, ultimately realizing circular waveguide™ 01 High-efficiency transmission of curved patterns.

[0026] According to the present invention, a compact broadband circular waveguide™ 01 Composition of mode-bending structures, compact broadband circular waveguide™ 01 The parameters of the mode bending structure satisfy: For the first circular waveguide TM 01 Mode power divider and second circular waveguide™ 01 Mode power divider, N≥4, and N is an even number. Compact broadband circular waveguide TE 01The power capacity, operating bandwidth, and compactness of a curved structure are all related to the value of N. A larger value of N results in higher power capacity and a wider operating bandwidth, but also increases the lateral dimensions and axial length of the circular waveguide, leading to reduced compactness. Therefore, a comprehensive trade-off must be made between power capacity, operating bandwidth, and compactness when designing curved structures in practice.

[0027] Using electromagnetic simulation software CST Studio Suite 2014 or later, while meeting the requirements... l 0>0, l 1>0, l 2>0, a 1> a 0> b 0>0, a 1=2 r 1×sin(180° / N), r 1> r 0> r 3> r 2>0, h 1>0, h 2>0, h 3>0, e r > a 0 / 2, e 1>0, e 2>0, e 3>0, e 4= h 3. Under the conditions of formula (1) and formula (2), the first circular waveguide TM is set. 01 The mode power divider has a reflection coefficient of less than -25dB and operates within the microwave frequency band. Parameters were obtained through optimization. r 0, l 0, l 1, l 2, a 0, b 0, r 1, r 3, r 2, h 1, h 2, h 3, e r , e 1, e 2, e 3, e The exact value of 4; For the first E-plane U-shaped bend waveguide, using electromagnetic simulation software CST Studio Suite 2014 or later, while meeting the following requirements... l 3> b 0,H >0, e 6> e Under the condition that 5>0, the operating frequency band of the first E-plane U-shaped bend waveguide with a reflection coefficient of less than -25dB is set to cover the microwave operating frequency band. Parameters are obtained through optimization. l 3, H , e 5, e The exact value of 6; For the k'-th first rectangular curved waveguide, the included angle is... β It is a pre-designed circular waveguide™ based on the connection requirements of an external microwave transmission system. 01 The bending angle of the modal bending structure was determined using electromagnetic simulation software CST Studio Suite 2014 or later, while meeting the following requirements. l 4> b 0, e 8> e Under the condition 7>0, the operating frequency band of the k'th first rectangular bend waveguide with a reflection coefficient less than -25dB is set to cover the microwave operating frequency band. Parameters are obtained through optimization. l 4, e 7, e The exact value of 8; Two circular waveguides™ 01 Mode power divider (i.e., first circular waveguide™) 01 Mode power divider and second circular waveguide™ 01 The system consists of a mode power divider, two E-plane U-shaped folded waveguide arrays (i.e., the first E-plane U-shaped folded waveguide array and the second E-plane U-shaped folded waveguide array), and two E-plane rectangular bent waveguide arrays (i.e., the first E-plane rectangular bent waveguide array and the second E-plane rectangular bent waveguide array). During assembly, key dimensional parameters in each rectangular waveguide array are adjusted. d 1, d 2,…, d k' ,…, d n ; q 1, q 2,…, q k' ,…, q n ; p 1, p 2,…, p k' ,…, p n ; s 1, s 2,…, s k' ,…, sn ; c 1, c 2,…, c k' ,…, c n ; g 1, g 2,…, g k' ,…, g n ), ensuring the two circular waveguides TE 01 The microwave transmission path lengths of the N rectangular waveguides between the mode power dividers remain consistent, ultimately forming a circular waveguide™. 01 Pattern bending structure.

[0028] Compared with the prior art, the present invention has the following advantages: (1) This invention employs a coaxial waveguide TEM mode and a multi-path rectangular waveguide TE mode. 10 Mode as a circular waveguide TM 01 Intermediate transition modes of the mode-bending structure, via circular waveguide TM 01 Mode power divider implements input TM 01 Mode - Coaxial waveguide TEM mode - Multi-path rectangular waveguide TE 10 Highly efficient mode switching. This design effectively solves the mode competition problem caused by the direct bending of the overmode circular waveguide in traditional curved waveguide structures, thereby significantly improving the transmission efficiency of the curved structure to over 95%.

[0029] (2) The present invention adopts the E-plane U-shaped folded waveguide phase compensation technology. By adjusting the length of each rectangular waveguide in the E-plane U-shaped folded waveguide array, the two circular waveguides TM are ensured. 01 The length of each rectangular waveguide transmission path between the mode power dividers remains consistent. This method not only effectively widens the operating bandwidth of the curved structure (relative operating bandwidth greater than 40%), but also significantly reduces the lateral distance between the input / output ports, making the spacing between the input / output ports less than 5 times the center wavelength, thus improving the compactness of the curved structure.

[0030] (3) The present invention is made of metal materials and no dielectric material is added inside the waveguide. It has a high power capacity and the power capacity under vacuum conditions exceeds the GW level. Attached Figure Description

[0031] Figure 1 This invention relates to a compact broadband circular waveguide™ 01 A three-dimensional view of the patterned bending structure; Figure 2 for Figure 1 First Circular Waveguide™ 01Schematic diagram of the structure of mode power divider 1; Figure 2 (a) is the first circular waveguide TM 01 A three-dimensional view from the left side of mode power divider 1. Figure 2 (b) is the first circular waveguide TM 01 A cross-sectional view of mode power divider 1 along the AA' plane. Figure 2 (c) is the first circular waveguide TM 01 Bottom view of mode power divider 1; Figure 3 for Figure 1 A schematic diagram of the structure of the first E-plane U-shaped folded waveguide array 2; Figure 3 (a) is a three-dimensional view of the first E-plane U-shaped folded waveguide array 2. Figure 3 (b) is a three-dimensional view of the first E-plane U-shaped waveguide 22k' in the first E-plane U-shaped folded waveguide array 2; Figure 4 for Figure 1 A schematic diagram of the structure of the first E-plane rectangular curved waveguide array 3; Figure 4 (a) is a three-dimensional view of the first E-plane rectangular curved waveguide array 3. Figure 4 (b) is a three-dimensional view of the first rectangular bent waveguide 31k' in the first E-plane rectangular bent waveguide array 3; Figure 5 for Figure 1 A schematic diagram of the structure of the second E-plane rectangular curved waveguide array 4; Figure 6 for Figure 1 A schematic diagram of the structure of the second E-plane U-shaped folded waveguide array 5; Figure 7 for Figure 1 Second Circular Waveguide TM 01 Schematic diagram of the structure of mode power divider 2; Figure 8 The above are the S-parameter simulation results of the bending structure in the embodiment of the present invention. Figure 9 The above are the simulation results of the electric field distribution at a frequency of 9.7 GHz in an embodiment of the present invention. Detailed Implementation

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0033] like Figure 1 As shown, a compact broadband circular waveguide™ 01 The mode bending structure consists of two circular waveguides TM 01 Mode power divider (i.e., first circular waveguide™) 01 Mode power divider 1 and second circular waveguide TM 01The structure consists of a mode power divider (6), two E-plane U-shaped folded waveguide arrays (i.e., the first E-plane U-shaped folded waveguide array 2 and the second E-plane U-shaped folded waveguide array 5), and two E-plane rectangular bent waveguide arrays (i.e., the first E-plane rectangular bent waveguide array 3 and the second E-plane rectangular bent waveguide array 4). All components of the entire bent structure are made of metallic materials (preferably aluminum alloy). The first circular waveguide TM is defined. 01 The circular waveguide port of mode power divider 1 is the input terminal of this invention, and the second circular waveguide TM 01 The circular waveguide port of the mode power divider 6 is the output terminal of this invention.

[0034] Figure 2 for Figure 1 First Circular Waveguide TM 01 A schematic diagram of the structure of mode power divider 1. Figure 2 (a) is the first circular waveguide TM 01 A three-dimensional view from the left side of mode power divider 1. Figure 2 (b) is the first circular waveguide TM 01 A cross-sectional view of mode power divider 1 along the AA' plane. Figure 2 (c) is the first circular waveguide TM 01 Bottom view of Mode Power Divider 1. (Combined) Figure 2 (a) and Figure 2 (b) First circular waveguide TM 01 The mode power divider 1 consists of an input circular waveguide 11, a first circular waveguide 12, a first frustum matching structure 13, a first rectangular transition waveguide circular array 14, a first rectangular waveguide circular array 15, and a first H-plane curved waveguide array 16. The first circular waveguide TM 01 The mode power divider 1 is mirror-symmetric along the AA' and BB' planes, respectively. Combined Figure 2 (c) The upper end of the input circular waveguide 11 is the input terminal of this invention. The input circular waveguide 11 has a radius of... r 0, length is l A cylindrical shape with a radius of 0. To facilitate connection with other waveguide components in the HPM transmission system, the input circular waveguide has a radius of 11. r 0 equals the actual radius of the connected external circular waveguide. The upper end of the input circular waveguide 11 is used to receive the external input circular waveguide TM. 01 The mode microwave is connected at its lower end to the upper end of the first circular waveguide 12. The first circular waveguide 12 has a radius of... r 1, height is b A cylinder of 0, and r 1> r0>0. Because there is a discontinuity at the connection between the upper end of the first circular waveguide 12 and the lower end of the input circular waveguide 11, microwaves will experience a local electric field enhancement effect when propagating to this region, thus reducing the power capacity of the entire curved structure. To improve the power capacity, a rounded corner is used at this connection, with a chamfer radius of [missing information]. e 1. The circumferential region on the side of the first circular waveguide 12 is sequentially connected to N rectangular transition waveguides (N≥4, and N is an even number) in the first rectangular transition waveguide circular array 14.

[0035] like Figure 2 As shown in (c), to achieve efficient transmission of microwave energy to the first rectangular transition waveguide circular array 14, a first frustum matching structure 13 is coaxially embedded at the bottom of the first circular waveguide 12. The top of the first frustum matching structure 13 extends into the interior of the input circular waveguide 11, and its bottom is on the same plane as the bottom of the first circular waveguide 12. The first frustum matching structure 13, the input circular waveguide 11, and the first circular waveguide 12 are all centrally symmetrical along the central axis OO'. The first frustum matching structure 13 is composed of three cascaded impedance matching structures from top to bottom: the upper layer is a frustum impedance matching structure 131, the middle layer is a cylindrical impedance matching structure 132, and the lower layer is an arc-shaped frustum impedance matching structure 133. The radius of the top cross-section of the frustum impedance matching structure 131 is... r 2. The radius of the bottom cross-section is r 3, height is h 1, and r 0> r 3> r 2>0. To suppress the local electric field enhancement at the discontinuity of the outer periphery of the top cross-section of the frustum impedance matching structure 131, a rounded corner treatment is applied to the outer periphery of the top cross-section of the frustum impedance matching structure 131, with a rounded corner radius of 2. e 2. The lower end of the frustum impedance matching structure 131 is connected to the upper end of the cylindrical impedance matching structure 132. The cross-sectional radius of the cylindrical impedance matching structure 132 is equal to... r 3, height is h 2. There is also a discontinuity at the connection between the upper end of the cylindrical impedance matching structure 132 and the lower end of the frustum impedance matching structure 131. This is also addressed by rounding the corners, with a corner radius of [missing information]. e 3. The lower end of the cylindrical impedance matching structure 132 is connected to the upper end of the arc-shaped frustum impedance matching structure 133. The arc-shaped frustum impedance matching structure 133 is connected by a cross-sectional radius equal to... r 3. Height is h The bottom of the cylinder is rounded to form a shape with a chamfer radius of 3. e 4, and satisfy h 3= e 4. The main function of the frustum impedance matching structure 131 and the cylindrical impedance matching structure 132 is to match the TM impedance of the input circular waveguide 11.01 The microwave mode is efficiently converted into a coaxial waveguide TEM mode. Subsequently, the arc-shaped frustum impedance matching structure 133 converts the coaxial waveguide TEM mode into an N-way rectangular waveguide TE mode. 10 mode, and N rectangular waveguide TE 10 The modes are respectively input to N rectangular transition waveguides in the first rectangular transition waveguide circular array 14.

[0036] like AA As shown in (c), the first rectangular transition waveguide circular array 14 consists of N identical rectangular transition waveguides, which are uniformly arranged in a circle along the central axis OO', and are numbered 141, 142, ..., 14k, ..., 14N, where 1 ≤ k ≤ N. These N rectangular transition waveguides have the same dimensions, and the length of the wider side of their inner cross-section (closest to the central axis OO') is... a 1. The length of the narrow side is equal to b 0, the width of the outer (away from the central axis OO') cross-section is a 0, the length of the narrow side is equal to b 0, and a 1> a 0, the distance between the inner and outer cross sections is l 1, a 1=2 r 1×sin(180° / N). The inner end faces of each rectangular transition waveguide in the first rectangular transition waveguide circular array 14 are sequentially connected to the outer side face of the first circular waveguide 12, and the outer end faces are connected to the inner end faces of N first rectangular waveguides (labeled 151, 152, ..., 15k, ..., 15N) in the first rectangular waveguide circular array 15. The main function of the first rectangular transition waveguide circular array 14 is to reduce the reflection of microwave input to the TE10 mode of each rectangular waveguide in the first rectangular waveguide circular array 15, thereby improving microwave transmission efficiency. The first rectangular waveguide circular array 15 consists of N first rectangular waveguides with identical structures, which are uniformly arranged in a circle along the central axis OO', and labeled sequentially as 151, 152, ..., 15k, ..., 15N. These N first rectangular waveguides have the same dimensions, and the length of the wider side of their cross-section is equal to... a 0, the length of the narrow side is equal to b 0, length is l 2. Both the first rectangular transition waveguide circular array 14 and the first rectangular waveguide circular array 15 are along... BB 'Planar mirror symmetry, and also along AA'Planar mirror symmetry. The inner end faces of the N first rectangular waveguides of the first rectangular waveguide circular array 15 are respectively connected to the outer end faces of the N rectangular transition waveguides of the first rectangular transition waveguide circular array 14, and the inner end face of the kth first rectangular waveguide 15k is connected to the outer end face of the kth rectangular transition waveguide 14k. The outer end faces of the N first rectangular waveguides (labeled 151, 152, ..., 15k, ..., 15N) of the first rectangular waveguide circular array 15 are respectively connected to the inner end faces of the N first H-plane curved waveguides (labeled 161, 162, ..., 16k, ..., 16N) of the first H-plane curved waveguide array 16, and the outer end face of the kth first rectangular waveguide 15k is connected to the inner end face of the kth first H-plane curved waveguide 16k.'

[0037] The first H-plane curved waveguide array 16 consists of N first H-plane curved waveguides, numbered 161, 162, ..., 16k, ..., 16N respectively. This array is along... BB 'Planar mirror symmetry, also along Figure 3 'Planar mirror symmetry. The inner end face of each of the first H-plane curved waveguides in the first H-plane waveguide array 16 is connected to the outer end face of N first rectangular waveguides in the first rectangular waveguide circumferential array 15, and the inner end face of the k-th first H-plane curved waveguide 16k is connected to the outer end face of the k-th first rectangular waveguide 15k. The cross-sectional width of each of the N first H-plane curved waveguides in the first H-plane waveguide array 16 is equal to...' a 0, the length of the narrow side is equal to b 0, bending radius is 0 e r ,and e r > a 0 / 2. The bending angle of the k-th first H-plane bend waveguide among N first H-plane bend waveguides, 16k. Calculated using formula (1) or formula (2).

[0038] After the N first H-plane curved waveguides of the first H-plane curved waveguide array 16 are bent according to the bending angle calculated by formula (1) or formula (2), their outer end faces will all be parallel to the BB' plane. Among them, the outer end faces of the n first H-plane curved waveguides (labeled as 161, 162, ..., 16k', ..., 16n, 1≤k'≤n) on the left side of the first H-plane curved waveguide array 16 are respectively parallel to the n second rectangular waveguides (labeled as ...) of the first rectangular waveguide array 21 of the first E-plane U-shaped folded waveguide array 2. The input ports of the n first H-plane curved waveguides (labeled as 16(n+1), 16(n+2), ..., 16k'', ..., 16N, n+1≤k''≤N) on the right side of the first H-plane curved waveguide array 16 are respectively connected to the input ports of the n tenth rectangular waveguides (labeled as 411, 412, ..., 41k', ..., 41n) of the fourth rectangular waveguide array 41 of the second E-plane rectangular curved waveguide array 4.

[0039] First Circular Waveguide™ 01 The function of mode power divider 1 is to divide the TM input of circular waveguide 11 into the mode power divider 1. 01 High-efficiency conversion of mode microwave to N-way rectangular waveguide TE 10 This transforms the complex bending problem of overmode circular waveguides into a bending problem of N-channel single-mode rectangular waveguides, fundamentally eliminating the mode competition problem present in the traditional bending process of overmode circular waveguides.

[0040] Figure 1 for Figure 3 A schematic diagram of the structure of the first E-plane U-shaped folded waveguide array 2; Figure 3 (a) is a three-dimensional view of the first E-plane U-shaped folded waveguide array 2. Figure 1 (b) is a three-dimensional view of the first E-plane U-shaped waveguide 22k' in the first E-plane U-shaped folded waveguide array 2. Figure 3 As shown, the first E-plane U-shaped folded waveguide array 2 consists of a first rectangular waveguide array 21, a first E-plane U-shaped bent waveguide array 22, and a second rectangular waveguide array 23. Figure 3 As shown in (a), the first rectangular waveguide array 21 contains n parallel second rectangular waveguides, labeled 211, 212, ..., 21k', ..., 21n (1 ≤ k' ≤ n). These second rectangular waveguides have the same cross-sectional dimensions (the length of the wider side is equal to...). a 0, the length of the narrow side is equal to b 0), with lengths respectively d 1, d 2,…, d k' ,…, d nThe input ports of the n second rectangular waveguides (labeled 211, 212, ..., 21k', ..., 21n) of the first rectangular waveguide array 21 are respectively connected to the output ports (outer end faces) of the n first H-plane curved waveguides (labeled 161, 162, ..., 16k', ..., 16n) on the left side of the first H-plane curved waveguide array 16. The output ports are respectively connected to the input ports above the n first E-plane U-shaped curved waveguides (labeled 221, 222, ..., 22k', ..., 22n) of the first E-plane U-shaped curved waveguide array 22.

[0041] The first E-plane U-shaped bend waveguide array 22 consists of n parallel U-shaped bend waveguides with identical structures (labeled sequentially as 221, 222, ..., 22k', ..., 22n). Combined with... Figure 4 (b) Taking the k'th first E-plane U-shaped bend waveguide 22k' as an example, it is composed of the fourth rectangular waveguide 22k'1, the fifth rectangular waveguide 22k'2, and the sixth rectangular waveguide 22k'3. The k'th first E-plane U-shaped bend waveguide 22k' is mirror-symmetrical along the CC' plane. The right port of the fourth rectangular waveguide 22k'1 is the microwave input port of the k'th first E-plane U-shaped bend waveguide 22k', and the right port of the sixth rectangular waveguide 22k'3 is the microwave output port of the k'th first E-plane U-shaped bend waveguide 22k'. The fourth rectangular waveguide 22k'1 and the sixth rectangular waveguide 22k'3 have the same structural dimensions, and the length of the wide side of their cross-sections is equal to... a 0, the length of the narrow side is equal to b 0, all lengths are l 3, and l 3> b 0. The fifth rectangular waveguide 22k'2 is used to connect the fourth rectangular waveguide 22k'1 and the sixth rectangular waveguide 22k'3, and the length of the wider side of its cross-section is equal to... a 0, the length of the narrow side is equal to b 0, length is H To suppress local electric field enhancement and broaden the operating bandwidth, a rounded corner is used at the junction of the fifth rectangular waveguide 22k'2 and the upper fourth rectangular waveguide 22k'1, wherein the inner chamfer radius is [missing information]. e 5. The outer chamfer radius is e 6, and e 6> e 5>0. Similarly, a rounded corner is also used at the junction of the fifth rectangular waveguide 22k'2 and the sixth rectangular waveguide 22k'3 below, where the inner chamfer radius is equal to e 5. The outer chamfer radius is equal to e6. The input ports of the n first E-plane U-shaped bend waveguides (labeled 221, 222, ..., 22k', ..., 22n) of the first E-plane U-shaped bend waveguide array 22 are respectively connected to the output ports of the n second rectangular waveguides (labeled 211, 212, ..., 21k', ..., 21n) of the first rectangular waveguide array 21, and the output ports are respectively connected to the input ports of the n third rectangular waveguides (labeled 231, 232, ..., 23k', ..., 23n) of the second rectangular waveguide array 23.

[0042] The second rectangular waveguide array 23 also contains n parallel third rectangular waveguides, labeled 231, 232, ..., 23k', ..., 23n. These rectangular waveguides have the same cross-sectional dimensions (the length of the wider side is equal to...). a 0, the length of the narrow side is equal to b 0), with lengths respectively q 1, q 2,…, q k' ,…, q n The input ports of the n third rectangular waveguides (labeled 231, 232, ..., 23k', ..., 23n) of the second rectangular waveguide array 23 are respectively connected to the output ports below the n E-plane U-shaped waveguides (labeled 221, 222, ..., 22k', ..., 22n) of the first E-plane U-shaped waveguide array 22, and the output ports are respectively connected to the input ports of the n first rectangular waveguides (labeled 311, 312, ..., 31k', ..., 31n) of the first E-plane rectangular waveguide array 3.

[0043] The main function of the first E-plane U-shaped folded waveguide array 2 is to achieve phase compensation and bandwidth extension. By adjusting the lengths of each rectangular waveguide in the first rectangular waveguide array 21 and the second rectangular waveguide array 23, the first circular waveguide TM is... 01 Mode power divider 1 left side and second circular waveguide TM 01 The rectangular waveguide paths and phases between the mode power dividers 6 are compensated to keep their transmission path lengths consistent, thereby significantly improving the operating bandwidth of the entire curved structure.

[0044] like Figure 1 As shown, the first E-plane rectangular curved waveguide array 3 consists of a first rectangular curved waveguide array 31 and a third rectangular waveguide array 32. The first rectangular curved waveguide array 31 consists of n parallel first rectangular curved waveguides with identical structures, numbered 311, 312, ..., 31k', ..., 31n (1 ≤ k' ≤ n). Taking the k'-th first rectangular curved waveguide 31k' as an example, this first rectangular curved waveguide is composed of the seventh rectangular waveguide 31k'1 and the eighth rectangular waveguide 31k'2 arranged at an angle... βThey are composed of inclined, staggered combinations. The seventh rectangular waveguide 31k'1 and the eighth rectangular waveguide 31k'2 have the same structural dimensions, with the width of each side being equal to... a 0, the length of the narrow side is equal to b 0, all lengths are l 4, and l 4> b 0. To suppress local electric field enhancement and broaden the operating bandwidth, a rounded corner is used at the junction of the seventh rectangular waveguide 31k'1 and the eighth rectangular waveguide 31k'2, wherein the inner chamfer radius is [missing information]. e 7. The outer chamfer radius is e 8, and e 8> e 7>0. The input ports on the left side of the n first rectangular curved waveguides (labeled 311, 312, ..., 31k', ..., 31n) of the first rectangular curved waveguide array 31 are respectively connected to the output ports of the n third rectangular waveguides (labeled 231, 232, ..., 23k', ..., 23n) of the second rectangular waveguide array 23. The output ports above the n first rectangular curved waveguides (labeled 311, 312, ..., 31k', ..., 31n) of the first rectangular curved waveguide array 31 are respectively connected to the input ports below the n ninth rectangular waveguides (labeled 321, 322, ..., 32k', ..., 32n) of the third rectangular waveguide array 32.

[0045] The third rectangular waveguide array 32 comprises n parallel ninth rectangular waveguides, labeled 321, 322, ..., 32k', ..., 32n. These ninth rectangular waveguides have identical cross-sectional dimensions (the length of their wider side is equal to...). a 0, the length of the narrow side is equal to b 0), with lengths respectively p 1, p 2,…, p k' ,…, p n The input ports below the n ninth rectangular waveguides (labeled 321, 322, ..., 32k', ..., 32n) of the third rectangular waveguide array 32 are respectively connected to the output ports above the n first rectangular curved waveguides (labeled 311, 312, ..., 31k', ..., 31n) of the first rectangular curved waveguide array 31. The output ports above the n ninth rectangular waveguides (labeled 321, 322, ..., 32k', ..., 32n) of the third rectangular waveguide array 32 are respectively connected to the second circular waveguide TM. 01 The input ports of the n second H-plane curved waveguides (labeled 661, 662, ..., 66k', ..., 66n) below the second H-plane curved waveguide array 66 of the mode power divider 6 are connected (see [link]). Figure 5 ).

[0046] like Figure 1 As shown, the second E-plane rectangular curved waveguide array 4 consists of a fourth rectangular waveguide array 41 and a second rectangular curved waveguide array 42. The fourth rectangular waveguide array 41 contains n parallel tenth rectangular waveguides, labeled 411, 412, ..., 41k', ..., 41n (1 ≤ k' ≤ n). These tenth rectangular waveguides have the same cross-sectional dimensions (the length of their widest side is equal to...). a 0, the length of the narrow side is equal to b 0), with lengths respectively s 1, s 2,…, s k' ,…, s n The input ports on the left side of the n tenth rectangular waveguides (labeled 411, 412, ..., 41k', ..., 41n) of the fourth rectangular waveguide array 41 are respectively connected to the output ports of the n first H-plane curved waveguides (labeled 16(n+1), 16(n+2), ..., 16k'', ..., 16N) (n+1≤k''≤N) on the right side of the first H-plane curved waveguide array 16. The output ports on the right side of the n tenth rectangular waveguides (labeled 411, 412, ..., 41k', ..., 41n) of the fourth rectangular waveguide array 41 are respectively connected to the input ports on the left side of the n second rectangular curved waveguides (labeled 421, 422, ..., 42k', ..., 42n) (1≤k'≤n) of the second rectangular curved waveguide array 42.

[0047] The second rectangular curved waveguide array 42 has the same structural dimensions as the first rectangular curved waveguide array 31, and consists of n identical second rectangular curved waveguides, labeled 421, 422, ..., 42k', ..., 42n (1≤k≤n). The input ports on the left side of the n second rectangular curved waveguides (labeled 421, 422, ..., 42k', ..., 42n) of the second rectangular curved waveguide array 42 are connected to the output ports on the right side of the n tenth rectangular waveguides (labeled 411, 412, ..., 41k', ..., 41n) of the fourth rectangular waveguide array 41, while the output ports above them are connected to the input ports below the n eleventh rectangular waveguides (labeled 511, 512, ..., 51k', ..., 51n) (1≤k'≤n) of the fifth rectangular waveguide array 51 of the second E-plane U-shaped folded waveguide array 5 (see [link to relevant documentation]). Figure 6 ).

[0048] The main function of the first E-plane rectangular bent waveguide array 3 and the second E-plane rectangular bent waveguide array 4 is to realize the circular waveguide™. 01 The bending function of the mode bending structure, the angle between the axial directions of the input circular waveguide 11 and the output circular waveguide 61 is equal to βIt can be set according to the spatial layout requirements of specific engineering applications. This customizable bending characteristic at any angle can significantly improve the flexibility of microwave transmission system layout.

[0049] Figure 1 for Figure 6 A schematic diagram of the structure of the second E-plane U-shaped folded waveguide array 5. (See diagram below.) Figure 7 As shown, similar to the composition of the first E-plane U-shaped folded waveguide array 2, the second E-plane U-shaped folded waveguide array 5 consists of a fifth rectangular waveguide array 51, a second E-plane U-shaped bend waveguide array 52, and a sixth rectangular waveguide array 53. The fifth rectangular waveguide array 51 contains n parallel eleventh rectangular waveguides, labeled 511, 512, ..., 51k', ..., 51n (1 ≤ k' ≤ n). These rectangular waveguides have the same cross-sectional dimensions (width equal to...). a 0, the length of the narrow side is equal to b 0), with lengths respectively c 1, c 2,…, c k' ,…, c n The second E-plane U-shaped bend waveguide array 52 consists of n parallel U-shaped bend waveguides with identical structures, labeled 521, 522, ..., 52k', ..., 52n. The structural dimensions of these n U-shaped bend waveguides are the same as those of the k'-th first E-plane U-shaped bend waveguide 22k' of the first E-plane U-shaped bend waveguide array 22. The input ports below the n tenth rectangular waveguides (labeled 511, 512, ..., 51k', ..., 51n) of the fifth rectangular waveguide array 51 are respectively connected to the output ports above the n second rectangular curved waveguides (labeled 421, 422, ..., 42k', ..., 42n) of the second rectangular curved waveguide array 42. The output ports above are respectively connected to the input ports at the lower left of the n second E-plane U-shaped curved waveguides (labeled 521, 522, ..., 52k', ..., 52n) of the second E-plane U-shaped curved waveguide array 52. The lower left input ports of the n second E-plane U-shaped bend waveguides (labeled 521, 522, ..., 52k', ..., 52n) of the second E-plane U-shaped bend waveguide array 52 are connected to the output ports above the n eleventh rectangular waveguides (labeled 511, 512, ..., 51k', ..., 51n) of the fifth rectangular waveguide array 51, and the lower right output ports are connected to the input ports above the n twelfth rectangular waveguides (labeled 531, 532, ..., 53k', ..., 53n) of the sixth rectangular waveguide array 53.

[0050] The sixth rectangular waveguide array 53 contains n parallel twelfth rectangular waveguides, labeled 531, 532, ..., 53k', ..., 53n. These twelfth rectangular waveguides have the same cross-sectional dimensions (the length of the wider side is equal to...). a 0, the length of the narrow side is equal to b 0), with lengths respectively g 1, g 2,…, g k' ,…, g n In terms of structural connections, the input ports above the n twelfth rectangular waveguides (labeled 531, 532, ..., 53k', ..., 53n) of the sixth rectangular waveguide array 53 are respectively connected to the lower right output ports of the n second E-plane U-shaped bend waveguides (labeled 521, 522, ..., 52k', ..., 52n) of the second E-plane U-shaped bend waveguide array 52, and the lower output ports are respectively connected to the second circular waveguide TM. 01 The input ports of the n second H-plane curved waveguides (labeled 66(n+1), 66(n+2), ..., 66k'', ..., 66N) above the second H-plane curved waveguide array 66 of the mode power divider 6 are connected.

[0051] Similar to the first E-plane U-shaped folded waveguide array 2, the second E-plane U-shaped folded waveguide array 5 also serves to provide phase compensation and bandwidth extension. By adjusting the lengths of the rectangular waveguides in the fifth rectangular waveguide array 51 and the sixth rectangular waveguide array 53, the first circular waveguide TM can be... 01 Mode power divider 1 right side and second circular waveguide TM 01 Each rectangular waveguide above the mode power divider 6 undergoes path and phase compensation to ensure consistent transmission path lengths, thereby significantly improving the overall operating bandwidth performance of the curved structure.

[0052] like θ As shown, the second circular waveguide TM 01 Mode power divider 6 and first waveguide TM 01The mode power divider 1 has the same structural dimensions and consists of an output circular waveguide 61, a second circular waveguide 62, a second frustum matching structure 63, a second rectangular transition waveguide circular array 64, a second rectangular waveguide circular array 65, and a second H-plane curved waveguide array 66. The input ports of the n second H-plane curved waveguides (labeled 661, 662, ..., 66k', ..., 66n) below the second H-plane curved waveguide array 66 are connected to the output ports above the n ninth rectangular waveguides (labeled 321, 322, ..., 32k', ..., 32n) of the third rectangular waveguide array 32. The input ports of the n second H-plane curved waveguides (labeled 66(n+1), 66(n+2), ..., 66k'', ..., 66N) above the second H-plane curved waveguide array 66 are respectively connected to the output ports below the n twelfth rectangular waveguides (labeled 531, 532, ..., 53k', ..., 53n) of the sixth rectangular waveguide array 53. Second circular waveguide TM 01 The main function of the mode power divider 6 is to convert the input N rectangular waveguides TE 10 Efficient mode conversion to circular waveguide™ 01 Mode output.

[0053] According to the present invention, a compact broadband circular waveguide™ 01 Composition of mode-bending structures, compact broadband circular waveguide™ 01 The parameters of the mode bending structure satisfy: For the first circular waveguide TM 01 Mode power divider 1 and second circular waveguide TM 01 Mode power divider 6, N≥4, and N is an even number. Compact broadband circular waveguide TE 01 The power capacity, operating bandwidth, and compactness of a curved structure are all related to the value of N. A larger value of N results in higher power capacity and a wider operating bandwidth, but also increases the lateral dimensions and axial length of the circular waveguide, leading to reduced compactness. Therefore, a comprehensive trade-off must be made between power capacity, operating bandwidth, and compactness when designing curved structures in practice.

[0054] Using electromagnetic simulation software CST Studio Suite 2014 or later, while meeting the requirements... l 0>0, l 1>0, l 2>0, a 1> a 0> b 0>0, a 1=2 r 1×sin(180° / N), r 1> r 0> r 3> r 2>0, h 1>0,h 2>0, h 3>0, e r > a 0 / 2, e 1>0, e 2>0, e 3>0, e 4= h 3. Under the conditions of formula (1) and formula (2), the first circular waveguide TM is set. 01 The mode power divider has a reflection coefficient of less than -25dB and operates within the microwave frequency band. Parameters were obtained through optimization. r 0, l 0, l 1, l 2, a 0, b 0, r 1, r 3, r 2, h 1, h 2, h 3, e r , e 1, e 2, e 3, e The exact value of 4; For the first E-plane U-shaped bend waveguide 22k', using electromagnetic simulation software CST Studio Suite 2014 or later, while meeting the requirements... l 3> b 0, H >0, e 6> e Under the condition that 5>0, the operating frequency band of the first E-plane U-shaped bend waveguide 221 with a reflection coefficient of less than -25dB is set to cover the microwave operating frequency band. The parameters are obtained through optimization. l 3, H , e 5, e The exact value of 6; For the k'-th first rectangular curved waveguide, the included angle is... β It is a pre-designed circular waveguide™ based on the connection requirements of an external microwave transmission system. 01 The bending angle of the modal bending structure was determined using electromagnetic simulation software CST Studio Suite 2014 or later, while meeting the following requirements. l 4> b 0, e 8> eUnder the condition 7>0, the operating frequency band of the k'th first rectangular bend waveguide with a reflection coefficient less than -25dB is set to cover the microwave operating frequency band. Parameters are obtained through optimization. l 4, e 7, e The exact value of 8; Two circular waveguides™ 01 Mode power divider (i.e., first circular waveguide™) 01 Mode power divider 1 and second circular waveguide TM 01 The mode power divider 6), two E-plane U-shaped folded waveguide arrays (i.e., the first E-plane U-shaped folded waveguide array 2 and the second E-plane U-shaped folded waveguide array 5), and two E-plane rectangular bent waveguide arrays (i.e., the first E-plane rectangular bent waveguide array 3 and the second E-plane rectangular bent waveguide array 4) are connected and assembled. During the assembly process, the key dimensional parameters in each rectangular waveguide array are adjusted. d 1, d 2,…, d k' ,…, d n ; q 1, q 2,…, q k' ,…, q n ; p 1, p 2,…, p k' ,…, p n ; s 1, s 2,…, s k' ,…, s n ; c 1, c 2,…, c k' ,…, c n ; g 1, g 2,…, g k' ,…, g n ), ensuring the two circular waveguides TE 01 The microwave transmission path lengths of the N rectangular waveguides between the mode power dividers remain consistent, ultimately forming a circular waveguide™. 01 Pattern bending structure.

[0055] Example 1 The following describes a broadband circular waveguide TE for the X-band (frequency range 8.2-12.5GHz, corresponding microwave wavelength range 36.6-24.0mm) with a center operating frequency of 9.7GHz (corresponding to a center wavelength of 30.93mm). 01 Specific design dimensions of an embodiment of the pattern bending structure: Depending on the application scenario, circular waveguide TE 01 The radius of the input circular waveguide 11 of the mode-bent structure r 0 is 27mm, the angle between the input circular waveguide 11 and the output circular waveguide 61 is... β The angle is 90°. To achieve a power capacity of GW, N is set to 6. The bending angle of each H-plane bend waveguide in the first H-plane bend waveguide array 16 can be calculated using equation (1). θ 1= θ 3= θ 4= θ 6 = 60° θ 2= Figure 8 5 = 0°. Following the optimization design steps for bending structures, the main parameters of the bending structure were obtained using the electromagnetic simulation software CST Studio Suite 2014, as shown in Table 1. Where 1 ≤ k' ≤ 3, 4 ≤ k'' ≤ 6.

[0056] Table 1

[0057] Based on the parameters above, the spacing between the input / output ports of Example 1 is approximately 149.67 mm (4.84 times the center wavelength), achieving the design goal of a compact structure.

[0058] The S-parameter simulation results of Example 1 are as follows: Figure 8 As shown, the solid line S 11 Represents a circular waveguide TM 01 After the mode microwave is input from the input circular waveguide 11, the circular waveguide TM 01 The reflection coefficient of the microwave reflected back to the input port. (Dashed line S) 21 Represents a circular waveguide TM 01 The mode microwave is input from the input circular waveguide 11 and output from the output circular waveguide 66. 01 The transmission coefficient of the mode microwave. (From...) Figure 9It can be seen that within the frequency range of 7.33-12.08 GHz, the reflection coefficient of Embodiment 1 is less than -13.41 dB and the transmission coefficient is greater than -0.22 dB, indicating that the transmission efficiency of Embodiment 1 is greater than 95%, and the relative operating bandwidth reaches more than 48.94% (2×(12.08-7.33) / (12.08+7.33)), which is 7.89% higher than the maximum relative operating bandwidth (45.36%) with a transmission efficiency greater than 95% in the background technology ((48.94%-45.36%) / 45.36%). At the same time, the spacing between the input / output ports is only 4.84 times the center wavelength, which meets the requirement of less than 5 times the center wavelength, indicating that Embodiment 1 has a compact structure.

[0059] Figure 9 The simulation results of the electric field distribution characteristics of Example 1 with an input microwave power of 0.5W at the center operating frequency of 9.7GHz are presented. ​ It can be seen that when the circular waveguide TM 01 The mode microwave is input from the input circular waveguide 11. Example 1 can effectively realize the circular waveguide™. 01 Mode - Coaxial waveguide TEM mode - 6-way rectangular waveguide TE 10 Mode - Coaxial Waveguide TEM Mode - Circular Waveguide TM 01 Mode transition. At this point, the maximum electric field amplitude inside it... It is 1080 V / m. Based on the electric field breakdown threshold under vacuum conditions. It is 700kV / cm, by The power capacity of the curved structure under vacuum conditions was calculated. It can reach 2.1GW. These simulation results show that this curved structure can not only realize circular waveguide™ 01 The curved transmission mode also has the advantages of compact structure, wide operating bandwidth, high power capacity and high transmission efficiency, and has extremely high practical value in the field of high-power microwave transmission technology.

[0060] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A compact broadband circular waveguide™ 01 The mode bending structure is characterized by Compact Broadband Circular Waveguide™ 01 The mode bending structure consists of two circular waveguides TM 01 Mode power divider, i.e., first circular waveguide TM 01 Mode power divider (1) and second circular waveguide TM 01 The system consists of a mode power divider (6), two E-plane U-shaped folded waveguide arrays (i.e., the first E-plane U-shaped folded waveguide array (2) and the second E-plane U-shaped folded waveguide array (5), and two E-plane rectangular bent waveguide arrays (i.e., the first E-plane rectangular bent waveguide array (3) and the second E-plane rectangular bent waveguide array (4); the entire bent structure is made of metal material; the first circular waveguide TM is defined. 01 The circular waveguide port of the mode power divider (1) is a compact broadband circular waveguide™. 01 Input end of the mode bending structure, second circular waveguide TM 01 The circular waveguide port of the mode power divider (6) is a compact broadband circular waveguide™. 01 Output end of the pattern bending structure; First Circular Waveguide™ 01 The mode power divider (1) consists of an input circular waveguide (11), a first circular waveguide (12), a first frustum matching structure (13), a first rectangular transition waveguide circular array (14), a first rectangular waveguide circular array (15), and a first H-plane curved waveguide array (16); the first circular waveguide TM 01 The mode power divider (1) is mirror-symmetric along the AA' plane and the BB' plane, respectively; the upper end of the input circular waveguide (11) is a compact broadband circular waveguide TM. 01 The input end of the mode bending structure; the input circular waveguide (11) has a radius of r 0, length is l 0 is a cylindrical shape; the upper end of the input circular waveguide (11) is used to receive the external input circular waveguide TM. 01 The mode microwave is connected at its lower end to the upper end of the first circular waveguide (12); the first circular waveguide (12) has a radius of... r 1, height is b A cylinder of 0, and r 1> r 0>0; The circular region on the side of the first circular waveguide (12) is sequentially connected to N rectangular transition waveguides in the circular array (14) of the first rectangular transition waveguide, where N≥4 and N is an even number; A first frustum matching structure (13) is coaxially embedded at the bottom of the first circular waveguide (12); the top of the first frustum matching structure (13) extends into the interior of the input circular waveguide (11), and the bottom is on the same plane as the bottom of the first circular waveguide (12); the first frustum matching structure (13), the input circular waveguide (11), and the first circular waveguide (12) are all centrally symmetrical along the central axis OO'; the first frustum matching structure (13) will connect the TM of the input circular waveguide (11) to the input circular waveguide (12). 01 The microwave mode is efficiently converted into a coaxial waveguide TEM mode, and then the coaxial waveguide TEM mode is converted into an N-way rectangular waveguide TE mode. 10 The mode will use N rectangular waveguides TE 10 The modes are respectively input to N rectangular transition waveguides in the first rectangular transition waveguide circular array (14); The first rectangular transition waveguide circular array (14) consists of N identical rectangular transition waveguides (141, 142, ..., 14k, ..., 14N), which are uniformly arranged in a circle along the central axis OO', where 1 ≤ k ≤ N; the length of the wider side of the inner cross-section of the rectangular transition waveguides (141, 142, ..., 14k, ..., 14N) is... a 1. The length of the narrow side is equal to b 0, the width of the outer cross-section is a 0, the length of the narrow side is equal to b 0, and a 1> a 0, the distance between the inner and outer cross sections is l 1; The inner end faces of the rectangular transition waveguides (141, 142, ..., 14k, ..., 14N) are sequentially connected to the outer side faces of the first circular waveguide (12), and the outer end faces are connected to the inner end faces of the N first rectangular waveguides (151, 152, ..., 15k, ..., 15N) in the first rectangular waveguide circular array (15); The function of the first rectangular transition waveguide circular array (14) is to reduce the microwave input to each rectangular waveguide TE in the first rectangular waveguide circular array (15). 10 The reflection of the pattern improves microwave transmission efficiency; the first rectangular waveguide circular array (15) consists of N identical first rectangular waveguides (151, 152, ..., 15k, ..., 15N), which are uniformly arranged in a circle along the central axis OO'; the first rectangular waveguides (151, 152, ..., 15k, ..., 15N) have the same dimensions, and the length of the wide side of their cross-section is equal to a 0, the length of the narrow side is equal to b 0, length is l 2; The first rectangular transition waveguide circular array (14) and the first rectangular waveguide circular array (15) are both along AA 'Planar mirror symmetry, and also along BB 'Planar mirror symmetry; the inner end faces of the first rectangular waveguides (151, 152, ..., 15k, ..., 15N) of the first rectangular waveguide circular array (15) are respectively connected to the outer end faces of the N rectangular transition waveguides of the first rectangular transition waveguide circular array (14), and the inner end face of the kth first rectangular waveguide (15k) is connected to the outer end face of the kth rectangular transition waveguide (14k); the outer end faces of the N first rectangular waveguides (15k) of the first rectangular waveguide circular array (15) are respectively connected to the inner end faces of the N first H-plane curved waveguides (161, 162, ..., 16k, ..., 16N) of the first H-plane curved waveguide array (16), and the outer end face of the kth first rectangular waveguide (15k) is connected to the inner end face of the kth first H-plane curved waveguide (16k); The first H-plane curved waveguide array (16) consists of N first H-plane curved waveguides 161, 162, ..., 16k, 16N; the first H-plane curved waveguide array (16) along... AA 'Plane mirror symmetry, also along BB The waveguides are planar mirror symmetric; the inner end faces of the first H-plane curved waveguides (161, 162, ..., 16k, ..., 16N) are connected to the outer end faces of the first rectangular waveguides (151, 152, ..., 15k, ..., 15N) of the first rectangular waveguide circular array (15), and the inner end face of the kth first H-plane curved waveguide (16k) is connected to the outer end face of the kth first rectangular waveguide (15k); the cross-sectional width of the N first H-plane curved waveguides (161, 162, ..., 16k, ..., 16N) is equal to the length of the wide side of each waveguide. a 0, the length of the narrow side is equal to b 0, bending radius is 0 e r The bending angle of the kth first H-plane curved waveguide (16k) is: After the N first H-plane curved waveguides of the first H-plane curved waveguide array (16) are bent according to the bending angle, their outer end faces are all parallel to the BB' plane. Among them, the outer end faces of the n first H-plane curved waveguides (161,162,…,16k',…,16n) on the left side of the first H-plane curved waveguide array (16) are respectively connected to the input ports of the n second rectangular waveguides (211,212,…,21k',…,21n) of the first rectangular waveguide array (21) of the first E-plane U-shaped folded waveguide array (2). , 1≤k'≤n; the outer end faces of the n first H-plane curved waveguides (16(n+1),16(n+2),…,16k'',…,16N) on the right side of the first H-plane curved waveguide array (16) are respectively connected to the input ports of the n tenth rectangular waveguides (411,412,…,41k',…,41n) of the fourth rectangular waveguide array (4) of the second E-plane rectangular curved waveguide array (4), n+1≤k''≤N; First Circular Waveguide™ 01 The function of the mode power divider (1) is to divide the TM of the input circular waveguide (11) into the mode power divider. 01 High-efficiency conversion of mode microwave to N-way rectangular waveguide TE 10 model; The first E-plane U-shaped folded waveguide array (2) consists of a first rectangular waveguide array (21), a first E-plane U-shaped bend waveguide array (22), and a second rectangular waveguide array (23); the first rectangular waveguide array (21) contains n parallel second rectangular waveguides (211,212,…,21k',…,21n); the width of the cross-section of the second rectangular waveguide (211,212,…,21k',…,21n) is equal to the length of the wide side of the cross-section. a 0, the length of the narrow side is equal to b 0, with lengths respectively d 1, d 2,…, d k' ,…, d n The input ports of the n second rectangular waveguides (211, 212, ..., 21k', ..., 21n) of the first rectangular waveguide array (21) are respectively connected to the output ports of the n first H-plane curved waveguides (161, 162, ..., 16k', ..., 16n) on the left side of the first H-plane curved waveguide array (16), and the output ports are respectively connected to the input ports above the n first E-plane U-shaped curved waveguides (221, 222, ..., 22k', ..., 22n) of the first E-plane U-shaped curved waveguide array (22); The first E-plane U-shaped bend waveguide array (22) consists of n parallel and identical first E-plane U-shaped bend waveguides (221, 222, ..., 22k', ..., 22n); the k'th first E-plane U-shaped bend waveguide (22k') is composed of a fourth rectangular waveguide (22k'1), a fifth rectangular waveguide (22k'2), and a sixth rectangular waveguide (22k'3); the k'th first E-plane U-shaped bend waveguide (22k') is mirror-symmetrical along the CC' plane; the right port of the fourth rectangular waveguide (22k'1) is the microwave input port of the k'th first E-plane U-shaped bend waveguide (22k'), and the right port of the sixth rectangular waveguide (22k'3) is the microwave output port of the k'th first E-plane U-shaped bend waveguide (22k'). The fourth rectangular waveguide (22k'1) and the sixth rectangular waveguide (22k'3) have the same structural dimensions. The fifth rectangular waveguide (22k'2) is used to connect the fourth rectangular waveguide (22k'1) and the sixth rectangular waveguide (22k'3). The input ports of the n first E-plane U-shaped bend waveguides (221, 222, ..., 22k', ..., 22n) of the first E-plane U-shaped bend waveguide array (22) are respectively connected to the output ports of the n second rectangular waveguides (211, 212, ..., 21k', ..., 21n) of the first rectangular waveguide array (21). The output ports are respectively connected to the input ports of the n third rectangular waveguides (231, 232, ..., 23k', ..., 23n) of the second rectangular waveguide array (23). The second rectangular waveguide array (23) contains n parallel third rectangular waveguides (231, 232, ..., 23k', ..., 23n); the width of the cross-section of the third rectangular waveguide (231, 232, ..., 23k', ..., 23n) is equal to a 0, the length of the narrow side is equal to b 0, with lengths respectively q 1, q 2,…, q k' ,…, q n The input ports of the n third rectangular waveguides (231, 232, ..., 23k', ..., 23n) of the second rectangular waveguide array (23) are respectively connected to the output ports below the n E-plane U-shaped waveguides (221, 222, ..., 22k', ..., 22n) of the first E-plane U-shaped waveguide array (22), and the output ports are respectively connected to the input ports of the n first rectangular waveguides (311, 312, ..., 31k', ..., 31n) of the first E-plane rectangular waveguide array (3); The function of the first E-plane U-shaped folded waveguide array (2) is to achieve phase compensation and bandwidth expansion; by adjusting the length of each rectangular waveguide in the first rectangular waveguide array (21) and the second rectangular waveguide array (23), the first circular waveguide TM is... 01 The left side of the mode power divider (1) and the second circular waveguide TM 01 The rectangular waveguide paths and phases between the mode power divider (6) are compensated to ensure that their transmission path lengths are consistent, thus improving the compact broadband circular waveguide™ 01 The operating bandwidth of the mode; The first E-plane rectangular curved waveguide array (3) is composed of a first rectangular curved waveguide array (31) and a third rectangular waveguide array (32); the first rectangular curved waveguide array (31) is composed of n parallel first rectangular curved waveguides (311,312,…,31k',…,31n) with the same structure; the k'th first rectangular curved waveguide (31k') is composed of the seventh rectangular waveguide (31k'1) and the eighth rectangular waveguide (31k'2) arranged at an angle. β The seven rectangular waveguides (31k'1) and the eight rectangular waveguides (31k'2) are composed of inclined and staggered combinations; the structural dimensions of the seventh rectangular waveguide (31k'1) and the eighth rectangular waveguide (31k'2) are the same. The input ports on the left side of the n first rectangular waveguides (311,312,…,31k',…,31n) of the first rectangular waveguide array (31) are respectively connected to the output ports of the n third rectangular waveguides (231,232,…,23k',…,23n) of the second rectangular waveguide array (23). The output ports above the n first rectangular waveguides (311,312,…,31k',…,31n) of the first rectangular waveguide array (31) are respectively connected to the input ports below the n ninth rectangular waveguides (321,322,…,32k',…,32n) of the third rectangular waveguide array (32). The third rectangular waveguide array (32) contains n parallel ninth rectangular waveguides (321, 322, ..., 32k', ..., 32n); the width of each of the ninth rectangular waveguides (321, 322, ..., 32k', ..., 32n) is equal to a 0, the length of the narrow side is equal to b 0, with lengths respectively p 1, p 2,…, p k' ,…, p n The input ports below the n ninth rectangular waveguides (321, 322, ..., 32k', ..., 32n) of the third rectangular waveguide array (32) are respectively connected to the output ports above the n first rectangular curved waveguides (311, 312, ..., 31k', ..., 31n) of the first rectangular curved waveguide array (31). The output ports above the n ninth rectangular waveguides (321, 322, ..., 32k', ..., 32n) of the third rectangular waveguide array (32) are respectively connected to the second circular waveguide TM. 01 The input ports of the n second H-plane curved waveguides (661, 662, ..., 66k', ..., 66n) below the second H-plane curved waveguide array (66) of the mode power divider (6) are connected; The second E-plane rectangular curved waveguide array (4) is composed of the fourth rectangular waveguide array (41) and the second rectangular curved waveguide array (42); the fourth rectangular waveguide array (41) contains n parallel tenth rectangular waveguides (411,412,…,41k',…,41n); the cross-sectional width of each of the tenth rectangular waveguides (411,412,…,41k',…,41n) is equal to a 0, the length of the narrow side is equal to b 0, with lengths respectively s 1, s 2,…, s k' ,…, s n The input ports on the left side of the n tenth rectangular waveguides (411, 412, ..., 41k', ..., 41n) of the fourth rectangular waveguide array (41) are respectively connected to the output ports on the right side of the n first H-plane curved waveguides (16(n+1), 16(n+2), ..., 16k'', ..., 16N) in the first H-plane curved waveguide array (16). The output ports on the right side of the n tenth rectangular waveguides (411, 412, ..., 41k', ..., 41n) of the fourth rectangular waveguide array (41) are respectively connected to the input ports on the left side of the n second rectangular curved waveguides (421, 422, ..., 42k', ..., 42n) of the second rectangular curved waveguide array (42). The second rectangular curved waveguide array (42) has the same structural dimensions as the first rectangular curved waveguide array (31), and is composed of n second rectangular curved waveguides (421, 422, ..., 42k', ..., 42n) with the same structure. The input ports on the left side of the n second rectangular curved waveguides (421, 422, ..., 42k', ..., 42n) of the second rectangular curved waveguide array (42) are respectively connected to the output ports on the right side of the n tenth rectangular waveguides (411, 412, ..., 41k', ..., 41n) of the fourth rectangular waveguide array (41). The output ports on the top are respectively connected to the input ports below the n eleventh rectangular waveguides (511, 512, ..., 51k', ..., 51n) of the fifth rectangular waveguide array (5) of the second E-plane U-shaped folded waveguide array (5). The function of the first E-plane rectangular curved waveguide array (3) and the second E-plane rectangular curved waveguide array (4) is to realize the circular waveguide TM. 01 The bending function of the mode bending structure is such that the angle between the axial directions of the input circular waveguide (11) and the output circular waveguide (61) is equal to... β ; The second E-plane U-shaped folded waveguide array (5) consists of the fifth rectangular waveguide array (51), the second E-plane U-shaped bend waveguide array (52), and the sixth rectangular waveguide array (53); the fifth rectangular waveguide array (51) contains n parallel eleventh rectangular waveguides (511, 512, ..., 51k', ..., 51n); the width of the eleventh rectangular waveguide (511, 512, ..., 51k', ..., 51n) is equal to a 0, the length of the narrow side is equal to b 0, with lengths respectively c 1, c 2,…, c k' ,…, c n The second E-plane U-shaped waveguide array (52) consists of n parallel U-plane U-shaped waveguides (521, 522, ..., 52k', ..., 52n) with identical structures; the structural dimensions of the second E-plane U-shaped waveguides (521, 522, ..., 52k', ..., 52n) are the same as those of the k'th first E-plane U-shaped waveguide (22k') of the first E-plane U-shaped waveguide array (22); the input ports below the n tenth rectangular waveguides (511, 512, ..., 51k', ..., 51n) of the fifth rectangular waveguide array (51) are connected to the output ports above the n second rectangular waveguides (421, 422, ..., 42k', ..., 42n) of the second rectangular waveguide array (42), respectively. The output ports of the square are respectively connected to the lower left input ports of the n second E-plane U-shaped waveguides (521, 522, ..., 52k', ..., 52n) of the second E-plane U-shaped waveguide array (52); the lower left input ports of the n second E-plane U-shaped waveguides (521, 522, ..., 52k', ..., 52n) of the second E-plane U-shaped waveguide array (52) are respectively connected to the upper output ports of the n eleventh rectangular waveguides (511, 512, ..., 51k', ..., 51n) of the fifth rectangular waveguide array (51); the lower right output ports are respectively connected to the upper input ports of the n twelfth rectangular waveguides (531, 532, ..., 53k', ..., 53n) of the sixth rectangular waveguide array (53); The sixth rectangular waveguide array (53) contains n parallel twelfth rectangular waveguides (531, 532, ..., 53k', ..., 53n); the width of the twelfth rectangular waveguide (531, 532, ..., 53k', ..., 53n) is equal to a 0, the length of the narrow side is equal to b 0, with lengths respectively g 1, g 2,…, g k' ,…, g n The input ports above the n twelfth rectangular waveguides (531, 532, ..., 53k', ..., 53n) of the sixth rectangular waveguide array (53) are respectively connected to the output ports on the lower right of the n second E-plane U-shaped bend waveguides (521, 522, ..., 52k', ..., 52n) of the second E-plane U-shaped bend waveguide array (52), and the output ports below are respectively connected to the second circular waveguide TM. 01 The input ports of the n second H-plane curved waveguides (66(n+1), 66(n+2), ..., 66k'', ..., 66N) above the second H-plane curved waveguide array (66) of the mode power divider (6) are connected; The second E-plane U-shaped folded waveguide array (5) serves to compensate for phase and extend bandwidth; by adjusting the lengths of the rectangular waveguides in the fifth rectangular waveguide array (51) and the sixth rectangular waveguide array (53), the first circular waveguide TM is... 01 Mode power divider (1) right side and second circular waveguide TM 01 Path and phase compensation is performed on each rectangular waveguide above the mode power divider (6) to ensure consistent transmission path lengths and improve the compact broadband circular waveguide™ 01 Operating bandwidth performance of the mode bending structure; Second Circular Waveguide™ 01 Mode power divider (6) and first circular waveguide TM 01 The mode power divider (1) has the same structural dimensions and consists of an output circular waveguide (61), a second circular waveguide (62), a second frustum matching structure (63), a second rectangular transition waveguide circular array (64), a second rectangular waveguide circular array (65), and a second H-plane curved waveguide array (66). The n second H-plane curved waveguides (661, 662, ..., 66k', ..., 66n) below the second H-plane curved waveguide array (66) are connected to the n-th rectangular waveguide array (32). The output ports above the ninth rectangular waveguide (321, 322, ..., 32k', ..., 32n) are connected; the input ports of the n second H-plane curved waveguides (66(n+1), 66(n+2), ..., 66k'', ..., 66N) above the second H-plane curved waveguide array (66) are respectively connected to the output ports below the n twelfth rectangular waveguides (531, 532, ..., 53k', ..., 53n) of the sixth rectangular waveguide array (53); the second circular waveguide TM 01 The function of the mode power divider (6) is to divide the input N rectangular waveguide TE 10 Efficient mode conversion to circular waveguide™ 01 Mode output.

2. A compact broadband circular waveguide™ as described in claim 1 01 The mode bending structure is characterized by The compact broadband circular waveguide™ 01 The curved structure is made of aluminum alloy.

3. A compact broadband circular waveguide™ as described in claim 1 01 The mode bending structure is characterized by The connection between the upper end of the first circular waveguide (12) and the lower end of the input circular waveguide (11) is rounded, with a chamfer radius of [missing information]. e 1.

4. A compact broadband circular waveguide™ as described in claim 1 01 The mode bending structure is characterized by The first frustum matching structure (13) is composed of three cascaded impedance matching structures from top to bottom: the upper layer is a frustum impedance matching structure (131), the middle layer is a cylindrical impedance matching structure (132), and the lower layer is an arc-shaped frustum impedance matching structure (133); the top cross-sectional radius of the frustum impedance matching structure (131) is... r 2. The radius of the bottom cross-section is r 3, height is h 1, and r 0> r 3> r 2>0; The top cross-section of the frustum impedance matching structure (131) is rounded, with a chamfer radius of 1 / 2. e 2; The lower end of the frustum impedance matching structure (131) is connected to the upper end of the cylindrical impedance matching structure (132); the cross-sectional radius of the cylindrical impedance matching structure (132) is equal to r 3, height is h 2; The connection between the upper end of the cylindrical impedance matching structure (132) and the lower end of the frustum impedance matching structure (131) is rounded, with a chamfer radius of [missing information]. e 3; The lower end of the cylindrical impedance matching structure (132) is connected to the upper end of the arc-shaped frustum impedance matching structure (133); the arc-shaped frustum impedance matching structure (133) is connected to the upper end of the arc-shaped frustum impedance matching structure (133) through the cross-sectional radius equal to r 3. Height is h The bottom of the cylinder is rounded to form a shape with a chamfer radius of 3. e 4, and satisfy h 3= e 4; The frustum impedance matching structure (131) and the cylindrical impedance matching structure (132) will input the TM of the circular waveguide (11) 01 The microwave mode is efficiently converted into a coaxial waveguide TEM mode, and the arc-shaped frustum impedance matching structure (133) converts the coaxial waveguide TEM mode into an N-way rectangular waveguide TE mode. 10 mode, and N rectangular waveguide TE 10 The modes are respectively input to N rectangular transition waveguides in the first rectangular transition waveguide circular array (14).

5. A compact broadband circular waveguide™ as described in claim 1 01 The mode bending structure is characterized by The bending radii of the N first H-plane bent waveguides (161, 162, ..., 16k, ..., 16N) e r > a 0 / 2; the bending angle of the k-th first H-plane curved waveguide (16k). Calculated using formula (1) or formula (2): When n is even : （1） when When it is an odd number: （2）。 6. A compact broadband circular waveguide™ as described in claim 1 01 The mode bending structure is characterized by The width of the cross-sections of the fourth rectangular waveguide (22k'1) and the sixth rectangular waveguide (22k'3) is equal to... a 0, the length of the narrow side is equal to b 0, all lengths are l 3, and l 3> b 0; The length of the wide side of the cross-section of the fifth rectangular waveguide (22k'2) is equal to a 0, the length of the narrow side is equal to b 0, length is H The junction between the fifth rectangular waveguide (22k'2) and the upper fourth rectangular waveguide (22k'1) is rounded, with an inner chamfer radius of [missing information]. e 5. The outer chamfer radius is e 6, and e 6> e 5>0; The junction between the fifth rectangular waveguide (22k'2) and the sixth rectangular waveguide below (22k'3) is rounded, with the inner chamfer radius equal to 0. e 5. The outer chamfer radius is equal to e 6.

7. A compact broadband circular waveguide™ as described in claim 1 01 The mode bending structure is characterized by The width of both the seventh rectangular waveguide (31k'1) and the eighth rectangular waveguide (31k'2) is equal to... a 0, the length of the narrow side is equal to b 0, all lengths are l 4, and l 4> b 0; The junction between the seventh rectangular waveguide (31k'1) and the eighth rectangular waveguide (31k'2) is rounded, with the inner chamfer radius being [missing information]. e 7. The outer chamfer radius is e 8, and e 8> e 7>0.

8. A compact broadband circular waveguide™ as described in claim 1, 3, 5, or 6 01 The mode bending structure is characterized by The parameters r 0, l 0, l 1, l 2, a 0, b 0, r 1, r 3, r 2, h 1, h 2, h 3, e r , e 1, e 2, e 3, e The exact value of 4 is obtained by the following method: when satisfying... l 0>0, l 1>0, l 2>0, a 1> a 0> b 0>0, a 1=2 r 1×sin(180° / N), r 1> r 0> r 3> r 2>0, h 1>0, h 2>0, h 3>0, e r > a 0 / 2, e 1>0, e 2>0, e 3>0, e 4= h 3. Under the conditions of formula (1) and formula (2), the first circular waveguide TM is set. 01 The operating frequency range of the mode power divider (1) with a reflection coefficient of less than -25dB covers the microwave operating frequency band and is obtained through optimization by electromagnetic simulation software; the electromagnetic simulation software is CST Studio Suite 2014 or above.

9. A compact broadband circular waveguide™ as described in claim 7 01 The mode bending structure is characterized by The parameters l 3, H , e 5, e The exact value of 6 is obtained by the following method: when the following conditions are met... l 3> b 0, H >0, e 6> e Under the condition that 5>0, the working frequency band of the first E-plane U-shaped bend waveguide (221) with a reflection coefficient of less than -25dB is set to cover the microwave working frequency band. This is obtained by optimization through electromagnetic simulation software, which is CST Studio Suite 2014 or above.

10. A compact broadband circular waveguide™ as described in claim 8 01 The mode bending structure is characterized by The parameters l 4, e 7, e The exact value of 8 is obtained by the following method: [The following is a continuation of the previous sentence, but the context is unclear: "when satisfying..."] l 4> b 0, e 8> e Under the condition 7>0, the operating frequency band of the k'th first rectangular bend waveguide with a reflection coefficient of less than -25dB is set to cover the microwave operating frequency band. This is obtained by optimization using electromagnetic simulation software, specifically CST Studio Suite 2014 or later.

11. A compact broadband circular waveguide™ as described in claim 1 01 The mode bending structure is characterized by The radius of the input circular waveguide (11) r 0 equals the radius of the connected external circular waveguide; the included angle β It is a pre-designed circular waveguide™ based on the connection requirements of an external microwave transmission system. 01 The bending angle of the pattern bending structure, the parameter d 1, d 2,…, d k' ,…, d n ; q 1, q 2,…, q k' ,…, q n ; p 1, p 2,…, p k' ,…, p n ; s 1, s 2,…, s k' ,…, s n ; c 1, c 2,…, c k' ,…, c n ; g 1, g 2,…, g k' ,…, g n It is in the first circular waveguide TM 01 Mode power divider (1) and second circular waveguide TM 01 During the connection and assembly process of the mode power divider (6), the first E-plane U-shaped folded waveguide array (2), the second E-plane U-shaped folded waveguide array (5), the first E-plane rectangular bent waveguide array (3), and the second E-plane rectangular bent waveguide array (4), adjustments are made to ensure that the two circular waveguides TE 01 The microwave transmission path lengths of the N rectangular waveguides between the mode power dividers remain consistent.

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