A compact broadband circular waveguideTM 01 -TE 01 Mode Converter

Abstract

The present invention discloses a compact broadband circular waveguide TM 01 ‑TE 01 Mode converter. The present invention is composed of circular waveguide TM 01 Mode power divider, N rectangular waveguide polarization bending structures and circular waveguide TE 01 The circular waveguide is composed of a mode synthesizer and is arranged in a central rotational symmetric pattern along the central axis. 01 The power divider consists of an input circular waveguide, an arc chamfered structure, a disk waveguide, an H-plane disk output structure, and a truncated cone matching structure. The rectangular waveguide polarization bending structure consists of two E-plane rectangular bend waveguides and a rectangular waveguide. Circular WaveguideTM 01 Mode power splitter and circular waveguide TE 01 The mode synthesizer is rotated along the central axis and staggered by ψ. 01 The synthesizer consists of an output circular waveguide, a second arc chamfered structure, a second disk waveguide, an E-plane disk-shaped input structure, and a conical matching structure. The invention has high power capacity and transmission efficiency, small axial size, and a relatively wide working bandwidth with a transmission efficiency greater than 95%.

Description

Technical Field

[0001] The present invention relates to the field of high-power microwave transmission technology, and in particular to a compact broadband circular waveguide TM 01 -TE 01 Mode converter. Background Art

[0002] High-power microwave (HPM) is a strong electromagnetic pulse with high repetition frequency, short pulse and high peak power. It has important application value in industrial, civil and military fields. With the continuous development of HPM technology, the lightweight, compact and miniaturization technology of HPM system is becoming a research hotspot. At present, most high-power microwave sources, such as relativistic backward wave tubes and magnetically insulated oscillators, usually use circular waveguide TM 01 The electric field of this mode is symmetrically distributed on the circumference, and there are strong angular electric fields and axial currents on the waveguide wall. If this mode is directly used for transmission in a high-power microwave transmission system, there will be strong losses. 01 The mode also has a circularly symmetrical electric field, but its electric field is concentrated in the r / 2 (r is the radius of the circular waveguide) area of ​​the circular waveguide, and its direction is along the angular direction of the circular waveguide. The electric field on the waveguide wall is zero, which has the advantage of low high-frequency ohmic loss, making it very suitable for long-distance transmission of microwaves. Therefore, an efficient and compact circular waveguide TM is designed. 01 -TE 01 Mode converters are of great significance for improving the overall efficiency of high-power microwave transmission and emission systems.

[0003] Currently, researchers mainly use two methods to realize circular waveguideTM 01 -TE 01 Mode conversion. One is to use curved waveguide or serpentine waveguide to reconstruct the microwave electric field transmitted in the waveguide to achieve mode conversion [Chengwei Yuan, Qiang Zhang. Design of a TM 01 -TE 01 Transmission Line for High-Power Microwave Applications[J].IEEE Transactions on Plasma Science,2009,37(10):1908–1915(Yuan Chengwei, Zhang Qiang. TM for High-Power Microwave Applications 01 -TE 01Transmission line design [J]. IEEE Transactions on Plasma Science, 2009, 37(10): 1908–1915). This mode converter usually has a power capacity of GW, but its axial size is generally long (greater than 36 times the working wavelength), the relative working bandwidth is narrow (the relative working bandwidth is less than 6% when the transmission efficiency is greater than 95%), and the processing accuracy requirements are high. The second is to achieve mode conversion through the circular waveguide side wall coupling method. For example, N E-plane 90° rectangular bend waveguides, N 90° rectangular twist waveguides and N H-plane 90° rectangular bend waveguides are used to form a transmission channel, which are connected to the input TM 01 Mode circle waveguide and output TE 01 The side of the mode circular waveguide is connected to form an angularly symmetrical circular waveguideTM 01 -TE 01 Mode converter [Huang Huijun, Wang Xiaoshun, Wu Jiangniu, et al. A compact circular waveguide TM 01 -TE 01 Mode converter: CN105489976A[P].2016]. This mode converter has a compact structure in the angular direction and its power capacity can reach the GW level. However, in order to achieve a wider operating frequency band, it uses a longer 90° rectangular twist waveguide, resulting in the axial dimension of the entire mode converter exceeding 6 times the operating wavelength. Therefore, this mode converter is not suitable for application scenarios with strict restrictions on axial dimension. To further reduce the axial distance of the mode converter, researchers designed a compact circular waveguideTM 01 -TE 01 mode converter, which uses a circular waveguideTM 01 Mode two-way power splitting structure, two rectangular E-plane 90° bend waveguides with a phase difference of 180° and one circular waveguide TE 01 A compact high-power microwave TM 01 -TE 01 mode converter[J].Review ofScientific Instruments,2021,92(9):094703]. This mode converter is relatively compact in both axial and angular directions, and its power capacity can reach the GW level. However, its input / output ports are not coaxial. In addition, the narrow working bandwidth (the relative working bandwidth is less than 2% when the transmission efficiency is greater than 95%) also limits its application range. Zhang Qiang et al. proposed a compact high-power microwave TM with coaxial input / output. 01 -TE 01 Mode converter [Zhang Qiang, Xu Liang, Yuan Chengwei, et al. A compact high power microwave TM01 -TE 01 Mode converter: Patent No.: ZL202211028273.8], the converter is as follows Figure 1 As shown, it consists of a disk-shaped multi-channel energy power splitting structure, N polarization twisted waveguides with the same structure and a disk-shaped multi-channel energy synthesis structure, and is connected through a circular waveguide TM 01 Mode-N-channel H-plane rectangular waveguide TE 10 Mode-N-channel E-plane rectangular waveguide TE 10 Mode-Circular Waveguide TE 01 Mode conversion process to achieve Circular WaveguideTM 01 -TE 01 Mode conversion. The polarization twisted waveguide is the core component of the mode converter, such as Figure 2 (a) Figure 2 (a) is a three-dimensional schematic diagram of the structure; Figure 2 (b) is a top view of the structure; Figure 2 (c) is a front view of the structure; Figure 2 (d) is a cross-sectional view of the structure along the GG' section. The polarization twisted waveguide is composed of an H-plane rectangular waveguide, an E-plane rectangular waveguide, and an E-plane curved waveguide connected in sequence. The polarization twisted waveguide realizes the rectangular waveguide TE by connecting an E-plane rectangular waveguide above the wide side of the H-plane rectangular waveguide. 10 However, due to the H-plane rectangular waveguide TE 10 The electric field of the mode is concentrated in the middle of the wide side. After connecting the E-plane rectangular waveguide, the electric field in this area will be cut off, resulting in an electric field enhancement effect and impedance mismatch, which greatly reduces the power capacity and operating bandwidth of the mode converter (the relative operating bandwidth is about 3% when the transmission efficiency is greater than 95%). To achieve GW-level power capacity, the number of polarization twisted waveguides N usually needs to be greater than 20. However, too many polarization twisted waveguides will increase the lateral size of the mode converter and increase the complexity of processing. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the existing circular waveguide TM 01 -TE 01 Mode converters have technical difficulties such as narrow working bandwidth and long axial dimensions. We provide a compact broadband high-power microwave TM with high power capacity and transmission efficiency, small axial dimensions, and a transmission efficiency greater than 95% with a relatively large working bandwidth. 01 -TE 01 Mode converter.

[0005] The technical solution of the present invention is: a compact broadband circular waveguide TM 01 -TE 01 The mode converter consists of a circular waveguideTM 01Mode power divider, a group (a total of N, N is a positive integer and 6≤N≤12) of rectangular waveguide polarization bending structures and a circular waveguide TE 01 The mode synthesizer consists of three parts connected coaxially in sequence, with OO' being the central axis of the present invention. These three parts are made of metal materials (such as aluminum alloy). The entire mode converter is arranged in a central rotationally symmetrical layout along the central axis OO', with an axial length of l. 01 The input end of the high power microwave mode is the input end of the present invention, that is, the left end of the present invention, and the circular waveguide TE 01 The output end of the high-power microwave mode is the output end of the present invention, that is, the right end of the present invention.

[0006] Circular WaveguideTM 01 The power divider consists of an input circular waveguide, a first arc chamfered structure, a first disk waveguide, an H-plane disk-shaped output structure, and a truncated cone-shaped matching structure. The input circular waveguide is a cylinder with an inner radius of r0 and an axial length of L. in , with a wall thickness of t. The left end of the input circular waveguide is the input end of the present invention. The right end of the input circular waveguide is coaxially connected to the left end of the first circular chamfered structure, and the right end of the first circular chamfered structure is coaxially connected to the inner left end surface of the first circular disk waveguide. The first circular chamfered structure is formed by chamfering the connection between the right end of the input circular waveguide and the inner left end of the first circular disk waveguide, and its chamfer radius is r b2 The main function of the first arc chamfer structure is to suppress the electric field enhancement effect caused by waveguide discontinuity, thereby improving the compact broadband circular waveguide TM 01 -TE 01 The power capacity of the mode converter. The outer end face of the first circular waveguide is connected to the H-plane disc output structure, and the radius of its outer end face is r1. The H-plane disc output structure consists of N H-plane trapezoidal waveguides with the same structure and N H-plane rectangular waveguides with the same structure. The outer side of each H-plane trapezoidal waveguide is connected to an H-plane rectangular waveguide and surrounds the circular waveguide TM 01 The central axis OO' of the power divider is arranged in an equiangular circular pattern, i.e., the angle between adjacent H-plane trapezoidal waveguides and the central axis OO' is θ = 360 / N. The bottom length of the wide side of the n-th trapezoidal waveguide is a1 = 2r1 sin(θ / 2), the top length of the wide side is a0, the length of the narrow side is b0, and the radial length is d1. The wide side length of the n-th rectangular waveguide is equal to a0, the length of the narrow side is equal to b0, and the height is l1. The truncated cone matching structure is located in the circular waveguide TM 01 The right end of the power divider is coaxially nested in the center of the input circular waveguide, the first arc chamfered structure, and the first disk waveguide space, and is connected to the inner right end face of the first disk waveguide. The frustum-shaped matching structure is composed of the top frustum, the middle cylinder, and the bottom frustum coaxially connected from left to right, and their wall thickness is equal to t. The top frustum is a hollow frustum with a bottom on the left end, and the radius of the left end face is r e1, the outer radius of the right end is r e2 , the axial length is l e1 In order to suppress the electric field enhancement effect caused by waveguide discontinuity, there is a radius r at the outer edge of the top left end of the top cone. b1 The right end of the top cone is coaxially connected to the left end of the middle cylinder. The outer radius of the middle cylinder is r e2 , the axial length is l e2 The right end of the middle cylinder is coaxially connected to the left end of the bottom cone. The bottom cone is a bottomless hollow cone with an outer radius of the left end equal to r e2 , the outer radius of the right end is r e3 , the axial length is l e3 The right end of the bottom cone is flush with the inner right end surface of the first disk waveguide. The first arc chamfer structure and the cone-shaped matching structure play a role in impedance matching between the input circular waveguide and the first disk waveguide. The top cone can 01 The mode microwave is gradually converted into the coaxial TEM mode, and then through the synergistic effect of the first arc chamfer structure, the bottom frustum and the first disk waveguide, the coaxial TEM mode is converted into N-way equal amplitude and phase H-plane rectangular waveguide TE 10 Efficient mode conversion.

[0007] The nth rectangular waveguide polarization bending structure in a set of rectangular waveguide polarization bending structures is composed of a first E-plane rectangular bend waveguide, a first rectangular waveguide, and a second E-plane rectangular bend waveguide connected in sequence. The first E-plane rectangular bend waveguide is composed of a second rectangular waveguide with a length of l2 and a 90° E-plane rectangular bend waveguide connected in sequence. The second rectangular waveguide is used as the input end and is connected to the circular waveguide TM 01 The output end of the nth H-plane rectangular waveguide of the power divider is connected. In order to ensure that the 90°E-plane rectangular bend waveguide has a high power capacity and a compact structure, the inner side of the 90°E-plane rectangular bend waveguide adopts a circular chamfer and the outer side adopts a triangular chamfer. The radius of the inner arc chamfer is r b3 The length of the outer longitudinal cutting angle is c1, and the length of the transverse cutting angle is c2. The output end of the 90° E-plane rectangular bend waveguide is connected to the input end of the first rectangular waveguide. The distance between the input end of the first rectangular waveguide 2n2 and the central axis OO' is d. The bottom of the first rectangular waveguide is closed, and a rectangular opening is opened near the narrow side on the inner side of the bottom, so that the transmission direction of the microwave is bent 90° along the inner side of the H plane. In order to suppress the reflection caused by the change in the direction of microwave transmission, a circular chamfer is used on the inner side of the bottom of the first rectangular waveguide, and a triangular chamfer is used on the outer side. The radius of the inner circular chamfer is r b4 The outer cut angle lengths are c3 and c4 respectively. The output end of the first rectangular waveguide is connected to the input end of the second E-plane rectangular bend waveguide. The second E-plane rectangular bend waveguide is composed of an E-plane bend waveguide and a third rectangular waveguide connected in sequence. The inner arc radius of the E-plane bend waveguide is r b6, the outer arc radius is r b5 , the bending angle is The third rectangular waveguide has a wide side length equal to a0, a narrow side length equal to b0, and a length of l4. 01 Mode power splitter and circular waveguide TE 01 The mode synthesizer is rotated along the central axis to stagger ψ. To ensure that the output end of the third rectangular waveguide in the nth rectangular waveguide polarization bending structure is aligned with the circular waveguide TE 01 The input end of the nth E-plane rectangular waveguide of the mode combiner is connected. According to the structural geometry, the specific dimensions of the E-plane curved waveguide must meet the following requirements:

[0008]

[0009] r b5 =r b6 +b0, d=r1+d1+l1+l2+r b3 (2)

[0010] It should be noted that when the ψ angle is too small, the inner and outer arc radii of the E-plane bend waveguide are both small, resulting in poor transmission characteristics of the E-plane bend waveguide and affecting the operating bandwidth of the entire mode converter. When the ψ angle is too large, the polarization bending structures of adjacent rectangular waveguides will overlap. Therefore, ψ is generally set to 20° to 30°.

[0011] Circular Waveguide TE 01 The synthesizer consists of an output circular waveguide, a second arc chamfered structure, a second disk waveguide, an E-plane disk input structure, and a conical matching structure. The output circular waveguide is a cylinder with an inner radius of r2 and an axial length of L. out , the wall thickness is equal to t. The right end of the output circular waveguide is the output end of the output circular waveguide, and is also the output end of the present invention. The left end of the output circular waveguide is coaxially connected to the right end of the second circular arc chamfered structure, and the left end of the second circular arc chamfered structure is coaxially connected to the inner right end surface of the second circular disk waveguide. The chamfer radius of the second circular arc chamfered structure is r b7 The outer end face of the second disk waveguide is connected to the E-plane disk input structure, and the radius of its outer end face is r3. The E-plane disk input structure consists of N E-plane trapezoidal waveguides and E-plane rectangular waveguides with the same structure. The outer side of each trapezoidal waveguide is connected to an E-plane rectangular waveguide and surrounds the circular waveguide TE. 01 The central axis OO' of the combiner is arranged in an equiangular circle, that is, the angle between adjacent trapezoidal waveguides and the central axis OO' is equal to θ. The bottom length of the narrow side of the nth trapezoidal waveguide is 2r3 sin(θ / 2), the top length of the narrow side is b0, the wide side length is a0, and the radial length is d2. The wide side length of the nth rectangular waveguide is equal to a0, the narrow side length is equal to b0, and the height is l5. The conical matching structure is located in the circular waveguide TE 01The left end of the synthesizer is coaxially nested in the center of the input circular waveguide, the second arc chamfered structure, and the second disk waveguide space, flush with the inner left end surface of the second disk waveguide. The conical matching structure is a hollow cone with an open left end, a thickness equal to t, a left end opening radius of c6, and an axial length of c5. When the circular waveguide TE 01 After the N E-plane rectangular waveguide input ends of the synthesizer simultaneously receive N equal-amplitude and in-phase microwave signals, the N equal-amplitude and in-phase E-plane rectangular waveguide TE 10 Mode to circular waveguide TE 01 Efficient synthesis of patterns.

[0012] The above parameters satisfy r1>r0>0, r3>r2>0, a0>b0>0, L in >0,r e3 >r e2 >r e1 >0, r0 is equal to the external TM 01 The inner radius of the high-power microwave circular waveguide is equal to the TE 01 The inner radius of the high-power microwave circular waveguide. t is generally 2 to 5 mm.

[0013] By using the electromagnetic simulation software CST Studio Suit 2014, under the conditions of r1>r0>0, r3>r2>0, a0>b0>0, L in >0,r e3 >r e2 >r e1 >0,l e1 >0,l e2 >0,l e3 >0,r b1 >0,r b2 >0,r b3 >0,r b4 >0,r b7 >0, d1>0, d2>0, l>0, l1>0, l2>0, l3>0, l4>0, l5>0, θ>0, d=r1+d1+l1+l2+r b3 , r b5 =r b6 +b0, c1>0, c2>0, c3>0, c4>0, c5>0, c6>0, 6≤N≤12, N is an integer, 20°<ψ<30°, r0 is equal to the external TM 01 The inner radius of the high-power microwave circular waveguide is equal to the TE 01Under the condition of the inner radius of the high power microwave circular waveguide, the transmission efficiency of the mode converter is set to be greater than 99% in the target frequency range. The parameters r1, r3, a0, b0, L can be obtained by optimization. in , L out , r e1 , r e2 , r e3 , l e1 , l e2 , l e3 , r b1 , r b2 , r b3 , r b4 , r b7 , the exact values ​​of d1, d2, l, l1, l2, l3, l4, l5, θ, c1, c2, c3, c4, c5, c6.

[0014] The working process of the present invention is:

[0015] First, high power microwaves are produced with circular waveguides 01 The mode is input from the left end of the input circular waveguide to the circular waveguideTM 01 Mode power divider. The top frustum connects the input of the circular waveguideTM 01 The mode microwave is gradually converted into the coaxial TEM mode. Through the synergistic effect of the first arc chamfer structure and the bottom frustum, the coaxial TEM mode microwave is converted into N-way H-plane rectangular waveguide TE with equal amplitude and phase. 10 mode and output it to the rectangular waveguide polarization bending structure.

[0016] The left end of a set of rectangular waveguide polarization bending structures and the circular waveguide TM 01 The N rectangular output ports of the mode power divider are connected, and the right end is connected to the circular waveguide TE 01 The N rectangular input ports of the mode power divider are connected. Each rectangular waveguide polarization bending structure can convert the input H-plane rectangular waveguide TE 10 The polarization direction of the mode microwave is converted to the E-plane rectangular waveguide TE 10 Therefore, N equal-amplitude and same-phase H-plane rectangular waveguide TE 10 The mode microwave is converted into N equal-amplitude and same-phase E-plane rectangular waveguide TE through N identical rectangular waveguide polarization bending structures. 10 mode microwave and input it into the circular waveguide TE 01 N rectangular inputs to the synthesizer.

[0017] When the circular waveguide TE 01 The N rectangular waveguide input ends of the synthesizer simultaneously receive N equal-amplitude and same-phase E-plane rectangular waveguide TE 10After the mode microwave, the synergistic effect of the second arc chamfer structure and the conical matching structure is achieved to realize N-way equal amplitude and phase E-plane rectangular waveguide TE 10 Mode to circular waveguide TE 01 Efficient synthesis of modes to complete Circular WaveguideTM 01 -TE 01 Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention uses a circular waveguide TM 01 Power divider and circular waveguide TE 01 The combiner is rotated along its central axis by an appropriate angle ψ to facilitate connection with the N rectangular waveguide polarization-bending structures of the present invention, achieving polarization twisting at the rectangular waveguide output ports of the power divider and combiner. Compared to 90° rectangular twist waveguides and polarization-twisted waveguides, the rectangular waveguide polarization-bending structure of the present invention significantly reduces the axial dimensions of the mode converter while maintaining a wider operating bandwidth and higher power capacity. The axial dimension of the present invention is less than four times the operating wavelength, and the relative operating bandwidth with a transmission efficiency greater than 95% is greater than 20%.

[0019] (2) The present invention is all metal structure, and the discontinuities inside the cavity are rounded or chamfered to effectively suppress the electric field enhancement effect and further improve its working bandwidth and power capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The overall structure diagram of the "A Compact High-Power Microwave TM01-TE01 Mode Converter" with patent number ZL202211028273.8 as background technology;

[0021] Figure 2 for Figure 1 A schematic structural diagram of the nth polarization twisted waveguide of the compact high-power microwave TM01-TE01 mode converter; wherein Figure 2 (a) is a three-dimensional schematic diagram of the n-th polarization twisted waveguide. Figure 2 (b) is the top view of the n-th polarization twisted waveguide. Figure 2 (c) is the front view of the nth polarization twisted waveguide. Figure 2 (d) is a cross-sectional view of the n-th polarization twisted waveguide along the GG' section;

[0022] Figure 3 This invention is a compact broadband circular waveguide TM 01 -TE 01 3D view of the mode converter;

[0023] Figure 4 This invention is a compact broadband circular waveguide TM 01-TE 01 Exploded view of the mode converter;

[0024] Figure 5 for Figure 4 Medium Circular Waveguide™ 01 Schematic diagram of the structure of the mode power divider; Figure 5 (a) is a circular waveguide TM 01 3D view of the mode power divider, Figure 5 (b) is a circular waveguide TM 01 Cross-sectional view of the mode power divider along the AA' plane;

[0025] Figure 6 for Figure 4 Schematic diagram of the nth rectangular waveguide polarization bending structure 2n; Figure 6 (a) is a three-dimensional view of the n-th rectangular waveguide polarization bending structure 2n. Figure 6 (b) is a three-dimensional view of the n-th rectangular waveguide polarization bending structure 2n cavity, Figure 6 (c) is the top view of the n-th rectangular waveguide polarization bending structure 2n cavity. Figure 6 (d) is the side view of the n-th rectangular waveguide polarization bending structure 2n cavity;

[0026] Figure 7 for Figure 4 Medium Circular Waveguide TE 01 Schematic diagram of the structure of the pattern synthesizer; Figure 7 (a) is a circular waveguide TE 01 3D view of Pattern Synthesizer 3, Figure 7 (b) is a circular waveguide TE 01 Cross-sectional view of the mode synthesizer along the BB' plane;

[0027] Figure 8 scattering parameter simulation results of Example 1 of the present invention;

[0028] Figure 9 This is the simulation result of the internal electric field distribution of Example 1 of the present invention at the center operating frequency point. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0030] like Figure 3 As shown, a compact broadband circular waveguideTM 01 -TE 01 The mode converter consists of a circular waveguideTM 01 Mode power divider 1, a group (a total of N, N is a positive integer and 6≤N≤12) of rectangular waveguide polarization bending structures 2 and a circular waveguide TE 01The mode synthesizer 3 consists of three parts connected coaxially in sequence, with OO' being the central axis of the present invention. These three parts are all made of metal materials (such as aluminum alloy). The entire mode converter is arranged in a central rotationally symmetrical layout along the central axis OO', and its axial length is l. 01 The input end of the high power microwave mode is the input end of the present invention, that is, the left end of the present invention, and the circular waveguide TE 01 The output end of the high-power microwave mode is the output end of the present invention, that is, the right end of the present invention.

[0031] Figure 4 for Figure 3 Exploded diagram, combined with Figure 5 , Circular WaveguideTM 01 The power divider 1 consists of an input circular waveguide 11, a first arc chamfered structure 12, a first disk waveguide 13, an H-plane disk-shaped output structure 14, and a truncated cone-shaped matching structure 15. The input circular waveguide 11 is a cylinder with an inner radius of r0 and an axial length of L. in , with a wall thickness of t. The left end of the input circular waveguide 11 is the input end of the present invention. The right end of the input circular waveguide 11 is coaxially connected to the left end of the first circular chamfered structure 12, and the right end of the first circular chamfered structure 12 is coaxially connected to the inner left end surface of the first circular disk waveguide 13. The first circular chamfered structure 12 is formed by chamfering the connection between the right end of the input circular waveguide 11 and the inner left end of the first circular disk waveguide 13, and its chamfer radius is r b2 The main function of the first arc chamfer structure 12 is to suppress the electric field enhancement effect caused by waveguide discontinuity, thereby improving the compact broadband circular waveguide TM 01 -TE 01 The power capacity of the mode converter. The outer end surface of the first circular waveguide 13 is connected to the H-plane disc output structure 14, and the radius of its outer end surface is r1. The H-plane disc output structure 14 is composed of N H-plane trapezoidal waveguides with the same structure and N H-plane rectangular waveguides with the same structure. The outer side of each H-plane trapezoidal waveguide is connected to an H-plane rectangular waveguide and surrounds the circular waveguide TM 01 The central axis OO' of the power divider 1 is arranged in an equiangular circle, that is, the angle between the adjacent H-plane trapezoidal waveguides and the central axis OO' is θ = 360 / N. The N H-plane trapezoidal waveguides and the H-plane rectangular waveguides are numbered in clockwise order. The N H-plane trapezoidal waveguides are numbered 1411, 1421, ..., 14n1, ..., 14N1. The N H-plane rectangular waveguides are numbered 1412, 1422, ..., 14n2, ..., 14N2 (e.g. Figure 5(a)). The bottom length of the wide side of the nth trapezoidal waveguide is a1 = 2r1 sin(θ / 2), the top length of the wide side is a0, the length of the narrow side is b0, and the radial length is d1. The wide side length of the nth rectangular waveguide is equal to a0, the length of the narrow side is equal to b0, and the height is l1. The truncated cone matching structure 15 is located in the circular waveguide TM 01 The right end of the power divider 1 is coaxially nested in the center of the space between the input circular waveguide 11, the first arc chamfered structure 12, and the first disk waveguide 13, and is connected to the inner right end face of the first disk waveguide 13. The frustum-shaped matching structure 15 is composed of a top frustum 151, a middle cylinder 152, and a bottom frustum 153 coaxially connected from left to right, and their wall thickness is equal to t. The top frustum 151 is a hollow frustum with a bottom on the left end, and the radius of the left end face is r e1 , the outer radius of the right end is r e2 , the axial length is l e1 In order to suppress the electric field enhancement effect caused by waveguide discontinuity, there is a radius r at the outer edge of the top left end of the top cone 151. b1 The right end of the top cone 151 is coaxially connected to the left end of the middle cylinder 152. The outer radius of the middle cylinder 152 is r e2 , the axial length is l e2 The right end of the middle cylinder 152 is coaxially connected to the left end of the bottom cone 153. The bottom cone 153 is a bottomless hollow cone with an outer radius of the left end equal to r e2 , the outer radius of the right end is r e3 , the axial length is l e3 The right end of the bottom cone 153 is flush with the inner right end surface of the first disk waveguide 13. The first arc chamfered structure 12 and the cone-shaped matching structure 15 play a role in impedance matching between the input circular waveguide 11 and the first disk waveguide 13. The top cone 151 can 01 The mode microwave is gradually converted into the coaxial TEM mode, and then the coaxial TEM mode is converted into the N-way equal amplitude and phase H-plane rectangular waveguide TE through the synergistic effect of the first arc chamfer structure 12, the bottom frustum 153 and the first disk waveguide 13. 10 Efficient mode conversion.

[0032] like Figure 6 As shown, combined Figure 8 The nth rectangular waveguide polarization bending structure 2n in a set of rectangular waveguide polarization bending structures 2 is composed of a first E-plane rectangular bend waveguide 2n1, a first rectangular waveguide 2n2, and a second E-plane rectangular bend waveguide 2n3 connected in sequence. The first E-plane rectangular bend waveguide 2n1 is composed of a second rectangular waveguide 2n11 with a length of l2 and a 90° E-plane rectangular bend waveguide 2n12 connected in sequence. The second rectangular waveguide 2n11 serves as the input end and is connected to the circular waveguide TM 01The output end of the nth H-plane rectangular waveguide 14n2 of the power divider 1 is connected. In order to ensure that the 90° E-plane rectangular bend waveguide 2n12 has a high power capacity and a compact structure, as shown in FIG. Figure 6 As shown in (b), the inner side of the 90°E-plane rectangular bend waveguide 2n12 adopts arc chamfering and the outer side adopts triangular chamfering. The radius of the inner arc chamfer is r b3 The length of the outer longitudinal cut angle is c1, and the length of the transverse cut angle is c2. The output end of the 90° E-plane rectangular bend waveguide 2n12 is connected to the input end of the first rectangular waveguide 2n2. The distance d between the input end of the first rectangular waveguide 2n2 and the central axis OO' is. The bottom of the first rectangular waveguide 2n2 is closed, and a rectangular opening 2n4 (such as Figure 6 (c) shows that the microwave transmission direction is bent 90° along the inner side of the H-plane. To suppress the reflection caused by the change in microwave transmission direction, the inner side of the bottom of the first rectangular waveguide 2n2 is chamfered with a circular arc, and the outer side is chamfered with a triangular corner. The radius of the inner chamfer is r b4 The outer cut angle lengths are c3 and c4 respectively. The output end of the first rectangular waveguide 2n2 is connected to the input end of the second E-plane rectangular bend waveguide 2n3. The second E-plane rectangular bend waveguide 2n3 is composed of an E-plane bend waveguide 2n31 and a third rectangular waveguide 2n32 connected in sequence. Figure 6 As shown in (d), the inner arc radius of the E-surface curved waveguide 2n31 is r b6 , the outer arc radius is r b5 , the bending angle is The third rectangular waveguide 2n32 has a wide side length equal to a0, a narrow side length equal to b0, and a length of l4. Figure 6 (d), Circular WaveguideTM 01 Mode power divider 1 and circular waveguide TE 01 The mode synthesizer 3 is rotated and staggered along the central axis ψ. To ensure that the output end of the third rectangular waveguide 2n32 in the nth rectangular waveguide polarization bending structure 2n is aligned with the circular waveguide TE 01 The input end of the nth E-plane rectangular waveguide 34n2 of the mode synthesizer 3 is connected. According to the structural geometric relationship, the specific dimensions of the E-plane curved waveguide 2n31 must meet the following requirements:

[0033]

[0034] r b5 =r b6 +b0, d=r1+d1+l1+l2+r b3 (2)

[0035] It should be noted that when the ψ angle is too small, the inner and outer arc radii of the E-plane bend waveguide 2n31 are both small, resulting in poor transmission characteristics of the E-plane bend waveguide 2n31 and affecting the operating bandwidth of the entire mode converter. When the ψ angle is too large, the polarization bending structures of adjacent rectangular waveguides will overlap. Therefore, ψ is generally set to 20° to 30°.

[0036] like Figure 4 As shown, combined Figure 7 , circular waveguide TE 01 The synthesizer 3 is composed of an output circular waveguide 31, a second arc chamfered structure 32, a second disk waveguide 33, an E-plane disk-shaped input structure 34 and a conical matching structure 35. Figure 7 As shown in (a), the output circular waveguide 31 is a cylinder with an inner radius of r2 and an axial length of L. out , the wall thickness is equal to t. The right end of the output circular waveguide 31 is the output end of the output circular waveguide 31, and is also the output end of the present invention. The left end of the output circular waveguide 31 is coaxially connected to the right end of the second circular arc chamfered structure 32, and the left end of the second circular arc chamfered structure 32 is coaxially connected to the inner right end surface of the second circular disk waveguide 33. The chamfer radius of the second circular arc chamfered structure 32 is r b7 The outer end face of the second circular waveguide 33 is connected to the E-plane disc-shaped input structure 34, and the radius of its outer end face is r3. The E-plane disc-shaped input structure 34 is composed of N E-plane trapezoidal waveguides and E-plane rectangular waveguides with the same structure. The outer side of each trapezoidal waveguide is connected to an E-plane rectangular waveguide and surrounds the circular waveguide TE. 01 The central axis OO' of the synthesizer 3 is arranged in an equiangular circle, that is, the angle between the adjacent trapezoidal waveguides and the central axis OO' is equal to θ. The N E-plane trapezoidal waveguides and the E-plane rectangular waveguides are numbered in clockwise order. The N E-plane trapezoidal waveguides are numbered 3411, 3421, ..., 34n1, ..., 34N1. The N E-plane rectangular waveguides are numbered 3412, 3422, ..., 34n2, ..., 34N2. The bottom length of the narrow side of the n-th trapezoidal waveguide is 2r3 sin (θ / 2), the top length of the narrow side is b0, the wide side length is a0, and the radial length is d2. The wide side length of the n-th rectangular waveguide 34n2 is equal to a0, the narrow side length is equal to b0, and the height is l5. As shown in FIG. Figure 7 As shown in (b), the conical matching structure 35 is located in the circular waveguide TE 01 The left end of the combiner 3 is coaxially nested in the center of the space between the input circular waveguide 31, the second arc chamfered structure 32, and the second disk waveguide 33, and is flush with the inner left end surface of the second disk waveguide 33. The conical matching structure 35 is a hollow cone with an open left end, a thickness equal to t, a left end opening radius of c6, and an axial length of c5. When the circular waveguide TE 01After the N E-plane rectangular waveguide input ends of the synthesizer 3 simultaneously receive N equal-amplitude and in-phase microwave signals, the N equal-amplitude and in-phase E-plane rectangular waveguide TE synthesizer 3 is realized through the synergistic effect of the second arc chamfer structure 32 and the conical matching structure 35. 10 Mode to circular waveguide TE 01 Efficient synthesis of patterns.

[0037] The above parameters satisfy r1>r0>0, r3>r2>0, a0>b0>0, r e3 >r e2 >r e1 >0, r0 is equal to the external TM 01 The inner radius of the high-power microwave circular waveguide is equal to the TE 01 The inner radius of the high-power microwave circular waveguide. t is generally 2 to 5 mm.

[0038] The working process of the present invention is as follows:

[0039] First, high power microwaves are produced with circular waveguides 01 The mode is input from the left end of the input circular waveguide 11 to the circular waveguide TM 01 Mode power divider 1. The top frustum 151 connects the input circular waveguide TM 01 The mode microwave is gradually converted into the coaxial TEM mode. Through the synergistic effect of the first arc chamfer structure 12 and the bottom frustum 153, the coaxial TEM mode microwave is converted into N-way H-plane rectangular waveguide TE 10 mode and output it to the rectangular waveguide polarization bending structure 2.

[0040] The left end of a set of rectangular waveguide polarization bending structures 2 and the circular waveguide TM 01 The N rectangular output ports of the mode power divider 1 are connected to the circular waveguide TE 01 The N rectangular input ports of the mode power divider 3 are connected. Each rectangular waveguide polarization bending structure can convert the input H-plane rectangular waveguide TE 10 The polarization direction of the mode microwave is converted to the E-plane rectangular waveguide TE 10 Therefore, N equal-amplitude and same-phase H-plane rectangular waveguide TE 10 The mode microwave is converted into N equal-amplitude and same-phase E-plane rectangular waveguide TE through N identical rectangular waveguide polarization bending structures. 10 mode microwave and input it into the circular waveguide TE 01 N rectangular input terminals of synthesizer 3.

[0041] When the circular waveguide TE 01 The N rectangular waveguide input ends of the synthesizer 3 simultaneously receive N equal-amplitude and same-phase E-plane rectangular waveguide TE 10After the mode microwave, the N-way equal amplitude and same phase E-plane rectangular waveguide TE is realized through the synergistic effect of the second arc chamfer structure 32 and the conical matching structure 35. 10 Mode to circular waveguide TE 01 Efficient synthesis of modes to complete Circular WaveguideTM 01 -TE 01 Mode conversion.

[0042] Example 1

[0043] The following is a compact broadband circular waveguide TM for the X-band (frequency range 8-12 GHz, corresponding to a microwave wavelength range of 37.50-25.00 mm) with a central operating frequency of 9.6 GHz (corresponding to a central microwave wavelength of 31.25 mm). 01 -TE 01 The specific design dimensions of an embodiment of the mode converter are as follows:

[0044] According to the application scenario, the radius r0 of the input circular waveguide 11 is 23.5mm, and the radius r2 of the output circular waveguide 31 is 24mm. According to the requirements of the mode converter, N is selected as 8, that is, θ = 45°, t is selected as 2mm, and the circular waveguide TM 01 Mode power divider 1 and circular waveguide TE 01 The mode synthesizer 3 is rotated 23° along the central axis, i.e., ψ = 23°. Based on the aforementioned mode converter size requirements, the main parameters of the mode converter were obtained after preliminary selection and optimization using the electromagnetic simulation software CST Studio Suit, as shown in Table 1.

[0045] Table 1

[0046] Structural parameters Dimensions (mm) Structural parameters Dimensions (mm) Structural parameters Dimensions (mm) <![CDATA[r1]]> 35.5 <![CDATA[l e3 ]]> 9.6 <![CDATA[l3]]> 20.2 <![CDATA[r3]]> 32 <![CDATA[r b1 ]]> 4 <![CDATA[l4]]> 2 <![CDATA[a0]]> 24 <![CDATA[r b2 ]]> 3 <![CDATA[l5]]> 2.3 <![CDATA[b0]]> 11 <![CDATA[r b3 ]]> 6 <![CDATA[c1]]> 10.5 <![CDATA[L in ]]> 10 <![CDATA[r b4 ]]> 4 <![CDATA[c2]]> 10.5 <![CDATA[r e1 ]]> 6.6 <![CDATA[r b7 ]]> 6 <![CDATA[c3]]> 15.8 <![CDATA[r e2 ]]> 12 <![CDATA[d1]]> 12 <![CDATA[c4]]> 15.8 <![CDATA[r e3 ]]> 21.6 <![CDATA[d2]]> 20 <![CDATA[c5]]> 20 <![CDATA[l e1 ]]> 9.6 <![CDATA[l1]]> 4 <![CDATA[c6]]> 20 <![CDATA[l e2 ]]> 14.6 <![CDATA[l2]]> 4 <![CDATA[L out ]]> 10

[0047] According to the above parameters, the axial length l of Example 1 is calculated to be about 105 mm (3.4 times the central microwave wavelength), achieving the design goal of small axial size. The scattering parameter simulation results of this embodiment are as follows: Figure 8 shown. Figure 8 In the figure, the horizontal axis is the frequency (GHZ), the vertical axis is the scattering parameters (including transmission coefficient and reflection coefficient), and the solid line S 11 Indicates TM 01 After the mode microwave enters the circular waveguide 11, it is reflected back to the TM 01 Reflection coefficient of mode microwave. Dashed line S 21 Indicates TM 01 After the mode microwave is input into the circular waveguide 11, the output circular waveguide 31 outputs the TE 01 The transmission coefficient of the mode microwave. Figure 8It can be seen that in the frequency range of 8.53-10.13 GHz, the reflection coefficient of Example 1 is less than -16 dB, and the transmission coefficient is greater than -0.10 dB, indicating that in the frequency range of 8.53-10.13 GHz, the mode conversion efficiency of Example 1 is greater than 98%; and in the frequency range of 8.50-10.85 GHz, the reflection coefficient of Example 1 is less than -15 dB, and the transmission coefficient is greater than -0.15 dB, indicating that in the frequency range of 8.50-10.85 GHz, the mode conversion efficiency of Example 1 is greater than 95%. That is, the relative working bandwidth of the mode conversion efficiency of this embodiment greater than 98% reaches 17.1% (2×(f max -f min ) / (f max +f min )×100%,f min =8.53GHz, f max =10.13GHz) or more. Similarly, the mode conversion efficiency of this embodiment is greater than 95% and the relative working bandwidth reaches 24.2% (2×(f max -f min ) / (f max +f min )×100%,f min =8.50GHz, f max =10.85GHz) or above.

[0048] Figure 9 The simulation results of the electric field distribution characteristics of Example 1 at the central operating frequency of 9.6 GHz when the input microwave power is 0.5 W are shown. Figure 9 The color scale on the right is used to represent the strength of the electric field. The closer the color is to red, the higher the electric field strength is; and the closer the color is to blue, the lower the electric field strength is. Figure 9 It can be seen that Example 1 can effectively realize the circular waveguide TM 01 Mode-TE 01 Mode conversion. The maximum electric field amplitude E on the right side 0.5W It is 1052V / m. According to the electric field breakdown threshold E under vacuum conditions b is 700kV / cm, The power capacity P of the mode converter under vacuum conditions is calculated b These simulation results show that the mode converter shown in Example 1 has the advantages of wide operating frequency band, small axial size, large power capacity, high mode conversion efficiency, etc., and has extremely high practical value in the technical field of high-power microwave transmission.

[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A compact broadband circular waveguide™ 01 -TE 01 mode converter, characterized in that Compact Broadband Circular Waveguide™ 01 -TE 01 The mode converter consists of a circular waveguideTM 01 Mode power divider (1), a set of rectangular waveguide polarization bending structures (2) and a circular waveguide TE 01 The mode synthesizer (3) is composed of three parts connected coaxially in sequence, and a set of rectangular waveguide polarization bending structures (2) has a total of N; these three parts are made of metal materials; the entire mode converter is arranged in a central rotation symmetrical layout along the central axis OO', and its axial length is l; the circular waveguide TM is defined 01 The input end of the high power microwave mode is a compact broadband circular waveguideTM 01 -TE 01 Mode converter input, also known as the Compact Broadband Circular Waveguide™ 01 -TE 01 Left end of the mode converter, circular waveguide TE 01 The output of the high power microwave mode is a compact broadband circular waveguideTM 01 -TE 01 Mode converter output, namely the Compact Broadband Circular Waveguide™ 01 -TE 01 right end of the mode converter; Circular WaveguideTM 01 The power divider (1) is composed of an input circular waveguide (11), a first circular arc chamfer structure (12), a first disk waveguide (13), an H-plane disk-shaped output structure (14), and a truncated cone-shaped matching structure (15); the input circular waveguide (11) is a cylinder with an inner radius of r0 and an axial length of L. in , with a wall thickness of t; the left end of the input circular waveguide (11) is a compact broadband circular waveguide TM 01 -TE 01 Mode converter input end; the right end of the input circular waveguide (11) is coaxially connected to the left end of the first circular arc chamfered structure (12), and the right end of the first circular arc chamfered structure (12) is coaxially connected to the inner left end surface of the first disk waveguide (13); the first circular arc chamfered structure (12) is formed by chamfering the connection between the right end of the input circular waveguide (11) and the inner left end of the first disk waveguide (13), and the chamfer radius is r b2 The first arc chamfer structure (12) suppresses the electric field enhancement effect caused by waveguide discontinuity, thereby improving the compact broadband circular waveguide TM 01 -TE 01 The power capacity of the mode converter; the outer end face of the first disk waveguide (13) is connected to the H-plane disk output structure (14), and the radius of the outer end face is r1; the H-plane disk output structure (14) is composed of N H-plane trapezoidal waveguides with the same structure and N H-plane rectangular waveguides with the same structure; the outer side of each H-plane trapezoidal waveguide is connected to an H-plane rectangular waveguide and surrounds the circular waveguide TM 01 The central axis OO' of the power divider (1) is arranged in an equiangular circle, that is, the angle θ between the adjacent H-plane trapezoidal waveguides and the central axis OO' is 360 / N; the N H-plane trapezoidal waveguides and the H-plane rectangular waveguides are numbered in clockwise order; the numbers of the N H-plane trapezoidal waveguides are 1411, 1421, ..., 14n1, ..., 14N1; the numbers of the N H-plane rectangular waveguides are 1412, 1422, ..., 14n2, ..., 14N2; the bottom length of the wide side of the n-th trapezoidal waveguide is a1 = 2r1sin (θ / 2), the top length of the wide side is a0, the length of the narrow side is b0, and the radial length is d1; the wide side length of the n-th rectangular waveguide is equal to a0, the length of the narrow side is equal to b0, and the height is l1; the truncated cone matching structure (15) is located at the circular waveguide TM 01 The power divider (1) is coaxially nested in the center of the space of the input circular waveguide (11), the first arc chamfered structure (12), and the first disk waveguide (13), and is connected to the inner right end face of the first disk waveguide (13); the frustum-shaped matching structure (15) is composed of a top frustum (151), a middle cylinder (152), and a bottom frustum (153) coaxially connected in sequence from left to right, and their wall thicknesses are all equal to t; wherein the top frustum (151) is a hollow frustum with a bottom at the left end, and the radius of the left end face is r e1 , the outer radius of the right end is r e2 , the axial length is l e1 ; There is a radius r at the outer edge of the left top of the top cone (151) b1 The right end of the top cone (151) is coaxially connected to the left end of the middle cylinder (152); the outer radius of the middle cylinder (152) is r e2 , the axial length is l e2 The right end of the middle cylinder (152) is coaxially connected to the left end of the bottom cone (153); the bottom cone (153) is a bottomless hollow cone with an outer radius of the left end equal to r e2 , the outer radius of the right end is r e3 , the axial length is l e3 The right end of the bottom truncated cone (153) is flush with the inner right end surface of the first disk waveguide (13); the first arc chamfered structure (12) and the truncated cone matching structure (15) jointly play the role of impedance matching between the input circular waveguide (11) and the first disk waveguide (13); the top truncated cone (151) connects the TM 01 The mode microwave is gradually converted into a coaxial TEM mode, and then the coaxial TEM mode is converted into an N-way equal-amplitude and same-phase H-plane rectangular waveguide TE through the coordinated action of the first arc chamfer structure (12), the bottom frustum (153) and the first disk waveguide (13). 10 Mode conversion; The nth rectangular waveguide polarization bending structure (2n) in a group of rectangular waveguide polarization bending structures (2) is composed of a first E-plane rectangular bend waveguide (2n1), a first rectangular waveguide (2n2) and a second E-plane rectangular bend waveguide (2n3) connected in sequence; the first E-plane rectangular bend waveguide (2n1) is composed of a second rectangular waveguide (2n11) with a length of l2 and a 90° E-plane rectangular bend waveguide (2n12) connected in sequence; the second rectangular waveguide (2n11) is used as an input end and is connected to the circular waveguide TM 01 The output end of the nth H-plane rectangular waveguide (14n2) of the power divider (1) is connected; the inner side of the 90° E-plane rectangular curved waveguide (2n12) adopts arc chamfering, and the outer side adopts triangular chamfering; the radius of the inner arc chamfer is r b3 The length of the outer longitudinal cutting angle is c1, and the length of the transverse cutting angle is c2; the output end of the 90° E-plane rectangular bend waveguide (2n12) is connected to the input end of the first rectangular waveguide (2n2); the bottom of the first rectangular waveguide (2n2) is closed, and a rectangular opening (2n4) is opened near the narrow side of the inner side of the bottom, so that the transmission direction of the microwave is bent 90° along the inner side of the H plane; the inner side of the bottom of the first rectangular waveguide (2n2) adopts a circular arc chamfer, and the outer side adopts a triangular chamfer; the radius of the inner circular arc chamfer is r b4 , the outer cutting angle lengths are c3 and c4 respectively; the output end of the first rectangular waveguide (2n2) is connected to the input end of the second E-plane rectangular bend waveguide (2n3); the second E-plane rectangular bend waveguide (2n3) is composed of an E-plane bend waveguide (2n31) and a third rectangular waveguide (2n32) connected in sequence; the inner arc radius of the E-plane bend waveguide (2n31) is r b6 , the outer arc radius is r b5 , the bending angle is The third rectangular waveguide (2n32) has a wide side length equal to a0, a narrow side length equal to b0, and a length of l4; the circular waveguide TM 01 Mode power divider 1 and circular waveguide TE 01 The mode synthesizer (3) is rotated and staggered along the central axis by ψ; Circular Waveguide TE 01 The synthesizer (3) is composed of an output circular waveguide (31), a second arc chamfered structure (32), a second disk waveguide (33), an E-plane disk-shaped input structure (34) and a conical matching structure (35); the output circular waveguide (31) is a cylinder with an inner radius of r2 and an axial length of L. out , the wall thickness is equal to t; the right end of the output circular waveguide (31) is the output end of the output circular waveguide (31), which is also a compact broadband circular waveguide TM 01 -TE 01 The output end of the mode converter; the left end of the output circular waveguide (31) is coaxially connected to the right end of the second circular arc chamfered structure (32); the left end of the second circular arc chamfered structure (32) is coaxially connected to the inner right end surface of the second disk waveguide (33); the chamfer radius of the second circular arc chamfered structure (32) is r b7 The outer end face of the second circular waveguide (33) is connected to the E-plane disc-shaped input structure (34), and the radius of the outer end face is r3; the E-plane disc-shaped input structure (34) is composed of N E-plane trapezoidal waveguides and E-plane rectangular waveguides with the same structure, and the outer side of each trapezoidal waveguide is connected to an E-plane rectangular waveguide and surrounds the circular waveguide TE 01 The central axis OO' of the synthesizer (3) is arranged in an equiangular circle, that is, the angle between adjacent trapezoidal waveguides and the central axis OO' is equal to θ; N E-plane trapezoidal waveguides and E-plane rectangular waveguides are numbered in clockwise order; the numbers of the N E-plane trapezoidal waveguides are 3411, 3421, ..., 34n1, ..., 34N1; the numbers of the N E-plane rectangular waveguides are 3412, 3422, ..., 34n2, ..., 34N2; the bottom length of the narrow side of the n-th trapezoidal waveguide is 2r3sin(θ / 2), the top length of the narrow side is b0, the wide side length is a0, and the radial length is d2; the wide side length of the n-th rectangular waveguide (34n2) is equal to a0, the narrow side length is equal to b0, and the height is l5; the conical matching structure (35) is located at the circular waveguide TE 01 The left end of the synthesizer (3) is coaxially nested in the center of the space of the input circular waveguide (31), the second arc chamfered structure (32), and the second disk waveguide (33), and is flush with the inner left end surface of the second disk waveguide (33); the conical matching structure (35) is a hollow cone with an open left end, a thickness equal to t, a left end opening radius of c6, and an axial length of c5; when the circular waveguide TE 01 After the N E-plane rectangular waveguide input ends of the synthesizer (3) simultaneously receive N equal-amplitude and in-phase microwave signals, the N equal-amplitude and in-phase E-plane rectangular waveguide TE synthesizer is realized through the coordinated action of the second arc chamfer structure (32) and the conical matching structure (35). 10 Mode to circular waveguide TE 01 Efficient synthesis of patterns.

2. A compact broadband circular waveguide™ as claimed in claim 1 01 -TE 01 mode converter, characterized in that N is a positive integer and 6≤N≤12.

3. A compact broadband circular waveguide™ as claimed in claim 1 01 -TE 01 mode converter, characterized in that The Circular Waveguide™ 01 Mode power divider (1), a set of rectangular waveguide polarization bending structures (2) and a circular waveguide TE 01 The mode synthesizer (3) is made of aluminum alloy.

4. A compact broadband circular waveguide™ as claimed in claim 1 01 -TE 01 mode converter, characterized in that The E-plane curved waveguide (2n31) meets the following requirements: ψ is 20° to 30°, and d is the distance between the input end of the first rectangular waveguide (2n2) and the central axis OO'.

5. A compact broadband circular waveguide™ as claimed in claim 1 01 -TE 01 mode converter, characterized in that r1>r0>0, r3>r2>0, a0>b0>0, r e3 >r e2 >r e1 >0, r0 is equal to the external TM 01 The inner radius of the high-power microwave circular waveguide is equal to the TE 01 The inner radius of the mode high-power microwave circular waveguide is t2 to 5 mm.

6. A compact broadband circular waveguide™ as claimed in claim 4 01 -TE 01 mode converter, characterized in that Through electromagnetic simulation software, when r1>r0>0, r3>r2>0, a0>b0>0, L in >0,r e3 >r e2 >r e1 >0,l e1 >0,l e2 >0,l e3 >0,r b1 >0,r b2 >0,r b3 >0,r b4 >0,r b7 >0, d1>0, d2>0, l>0, l1>0, l2>0, l3>0, l4>0, l5>0, θ>0, d=r1+d1+l1+l2+r b3 , r b5 =r b6 +b0, c1>0, c2>0, c3>0, c4>0, c5>0, c6>0, 6≤N≤12, N is an integer, 20°<ψ<30°, r0 is equal to the external TM 01 The inner radius of the high-power microwave circular waveguide is equal to the TE 01 Under the condition of the inner radius of the high-power microwave circular waveguide, the transmission efficiency of the mode converter is set to be greater than 99% in the target frequency range, and the parameters r1, r3, a0, b0, L are obtained by optimization. in , L out , r e1 , r e2 , r e3 , l e1 , l e2 , l e3 , r b1 , r b2 , r b3 , r b4 , r b7 , the exact values ​​of d1, d2, l, l1, l2, l3, l4, l5, θ, c1, c2, c3, c4, c5, c6.

7. A compact broadband circular waveguide™ as claimed in claim 6 01 -TE 01 mode converter, characterized in that The electromagnetic simulation software is CST Studio Suit 2014 version.

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