Compact broadband circular waveguide TM01-TE01 mode converter

Abstract

The invention discloses a compact type broadband circular waveguide TM01-TE01 mode converter, and relates to a TM01-TE01 mode converter. The antenna is composed of a circular waveguide TM01 mode power divider, N rectangular waveguide polarization bending structures and a circular waveguide TE01 mode synthesizer, and the circular waveguide TM01 mode power divider, the N rectangular waveguide polarization bending structures and the circular waveguide TE01 mode synthesizer are symmetrically arranged in a central rotation mode along a central axis. The circular waveguide TM01 power divider is composed of an input circular waveguide, an arc chamfer structure, a disc waveguide, an H-surface disc-shaped output structure and a circular-truncated-cone-shaped matching structure. The rectangular waveguide polarization bending structure is composed of two E-plane rectangular bent waveguides and a rectangular waveguide. And the circular waveguide TM01 mode power divider and the circular waveguide TE01 mode synthesizer are rotationally staggered by Psi along the central axis. The circular waveguide TE01 synthesizer is composed of an output circular waveguide, a second arc chamfer structure, a second disc waveguide, an E-surface disc-shaped input structure and a conical matching structure. The power capacity and the transmission efficiency are high, the axial size is small, and the relative working bandwidth with the transmission efficiency larger than 95% is wide.

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 miniaturized 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 around the circle, and there is a strong angular electric field and axial current 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 symmetrically distributed 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 the 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, so it is 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 waveguide TM 01 -TE 01 Mode conversion. One is to use curved waveguides or serpentine waveguides 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. Transmission Line for High-Power Microwave Applications[J].IEEE Transactions on Plasma Science, 2009, 37(10):1908–1915 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 sidewall 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 circular waveguide and output TE 01 The lateral sides of the mode circular waveguides are 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]. The 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 size 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 size. To further reduce the axial distance of the mode converter, the researchers designed a compact circular waveguide TM 01 -TE 01 mode converter, which uses a circular waveguideTM 01 Mode two-way power splitter structure, two rectangular E-plane 90° bend waveguides with a phase difference of 180° and one circular waveguide TE 01 The two-way synthesis structure of the model [Yongjun Hu, Liang Xu, Qiang Zhang, et al. A compact high-power microwave TM 01 -TE 01 mode converter[J].Review ofScientific Instruments,2021,92(9):094703]. This mode converter is compact in both axial and angular directions, and its power capacity can reach GW level. However, its input / output ports are not coaxial. In addition, the narrow working bandwidth (the relative working bandwidth with transmission efficiency greater than 95% is less than 2%) 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 division 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-way H-plane rectangular waveguide TE 10 Mode-N-channel E-plane rectangular waveguide TE 10 Mode-Circular Waveguide TE 01 Mode conversion process realizes circular waveguideTM 01 -TE 01 The polarization twisted waveguide is the core component of the mode converter. 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 electric field enhancement effect and impedance mismatch, which greatly reduces the power capacity and working bandwidth of the mode converter (the relative working bandwidth is about 3% when the transmission efficiency is greater than 95%). To achieve GW-level power capacity, the number N of polarization twisted waveguides 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 The mode converter has technical problems such as narrow working bandwidth and long axial size. A compact broadband high-power microwave TM with high power capacity and transmission efficiency, small axial size and transmission efficiency greater than 95% with large relative working bandwidth is provided. 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 waveguide TM 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 is composed of three parts connected coaxially in sequence, wherein OO' is 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 rotation symmetrical layout along the central axis OO', and its axial length is l. Definition of circular waveguide TM 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 of the 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 chamfer structure, a first disk waveguide, an H-plane disk output structure and a truncated cone matching structure. The input circular waveguide is a cylinder with an inner radius of r. 0 , axial length is L in , the wall thickness is 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 arc chamfered structure, and the right end of the first circular arc chamfered structure is coaxially connected to the inner left end surface of the first circular disk waveguide. The first circular arc 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 the 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 surface of the first disk waveguide is connected to the H-plane disk output structure, and the radius of its outer end surface is r 1 The H-plane disk-shaped 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 circle, that is, the angle between the adjacent H-plane trapezoidal waveguides and the central axis OO' is θ=360 / N. The bottom length of the wide side of the nth trapezoidal waveguide a 1 =2r 1 sin(θ / 2), the top length of the broad side is a 0 , the narrow side length is b 0 , radial length is d 1 The length of the wide side of the nth rectangular waveguide is equal to a 0 , the narrow side length is equal to b 0 , height l 1 The truncated cone matching structure is located in the circular waveguide TM 01The right end of the power divider is coaxially nested in the input circular waveguide, the first arc chamfered structure, and the center of the first disk waveguide space, and is connected to the inner right end face of the first disk waveguide. The truncated cone matching structure is composed of the top truncated cone, the middle cylinder, and the bottom truncated cone coaxially connected from left to right, and their wall thickness is equal to t. The top truncated cone is a hollow truncated cone 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, and the outer radius of the left end is 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 transformed into N-way equal-amplitude and in-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 bending waveguide, a first rectangular waveguide, and a second E-plane rectangular bending waveguide connected in sequence. The first E-plane rectangular bending waveguide consists of a section of length l 2 The second rectangular waveguide is connected in sequence with a 90°E-plane rectangular bend waveguide. The second rectangular waveguide is used as the input end and 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 circular chamfer is r b3 , the length of the outer longitudinal cutting angle is c 1 , the length of the transverse cutting angle is c 2. The output end of the 90°E-plane rectangular bend waveguide is connected to the input end of the first rectangular waveguide. The input end of the first rectangular waveguide 2n2 is at a distance d from the central axis OO'. 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 lengths of the outer cutting angles are c 3 、c 4 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 length of the wide side of the third rectangular waveguide is equal to a 0 , the narrow side length is equal to b 0 , the length is l 4 Circular WaveguideTM 01 Mode Power Divider 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 synthesizer is connected. According to the structural geometric relationship, the specific size of the E-plane curved waveguide must meet the following requirements:

[0008]

[0009] r b5 =r b6 +b 0 , d=r 1 +d 1 +l 1 +l 2 +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 curved waveguide are both small, resulting in poor transmission characteristics of the E-plane curved waveguide, affecting the working bandwidth of the entire mode converter; and when the ψ angle is too large, the adjacent rectangular waveguide polarization bending structures will overlap. Therefore, ψ is generally set to 20°~30°.

[0011] Circular Waveguide TE 01 The synthesizer consists of an output circular waveguide, a second arc chamfer 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 r.2 , axial length is 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 surface of the second disk waveguide is connected to the E-plane disk input structure, and the radius of its outer end surface is r 3 The E-plane disk-shaped 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 synthesizer is arranged in an equiangular circle, that is, the angle between adjacent trapezoidal waveguides and the central axis OO' is equal to θ. The length of the bottom of the narrow side of the nth trapezoidal waveguide is 2r 3 sin(θ / 2), the top length of the narrow side is b 0 , width length a 0 , radial length is d 2 The length of the wide side of the nth rectangular waveguide is equal to a 0 , the narrow side length is equal to b 0 , height l 5 The conical matching structure is located in the circular waveguide TE 01 The 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, and is 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, whose thickness is equal to t and the radius of the left end opening is c 6 , the axial length is c 5 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 r 1 >r 0 >0,r 3 >r 2 >0,a 0 >b 0 >0,L in >0,r e3 >r e2 >r e1 >0,r 0 Equivalent to external TM 01Inner radius of the high power microwave circular waveguide, r 2 Equal to the external TE 01 The inner radius of the high-power microwave circular waveguide. t is usually 2 to 5 mm.

[0013] Through the electromagnetic simulation software CST Studio Suit 2014 version, in meeting the requirements of r 1 >r 0 >0,r 3 >r 2 >0,a 0 >b 0 >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,d 1 >0,d 2 >0,l>0,l 1 >0,l 2 >0,l 3 >0,l 4 >0,l 5 >0,θ>0,d=r 1 +d 1 +l 1 +l 2 +r b3 , r b5 =r b6 +b 0 , c 1 >0,c 2 >0,c 3 >0,c 4 >0,c 5 >0,c 6 >0, 6≤N≤12, N is an integer, 20°<ψ<30°, r 0 Equivalent to external TM 01 Inner radius of the high power microwave circular waveguide, r 2 Equal to the external TE 01 Under the condition of the inner radius of the mode 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 parameter r can be obtained by optimization. 1 , r 3 , a0 , b 0 , L 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 , d 1 , d 2 ,l,l 1 , l 2 , l 3 , l 4 , l 5 ,θ,c 1 , c 2 , c 3 , c 4 , c 5 , c 6 The exact value of .

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

[0015] First, high-power microwaves are produced in circular waveguides TM 01 The mode is input from the left end of the input circular waveguide to the circular waveguide TM 01 Mode power divider. The top frustum 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 and the bottom truncated cone, the coaxial TEM mode microwave is converted into N-channel H-plane rectangular waveguide TE 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 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 Conversion of mode microwave polarization direction to 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 identically structured 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 10 After 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 same phase E-plane rectangular waveguide TE 10 Mode to circular waveguide TE 01 Efficient synthesis of modes, completing the 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 synthesizer is rotated along the central axis to stagger an appropriate angle ψ so as to connect with the N rectangular waveguide polarization bending structures of the present invention to achieve polarization twisting of the rectangular waveguide output ports of the power divider and the synthesizer. Compared with the 90° rectangular twist waveguide and the polarization twist waveguide, the rectangular waveguide polarization bending structure of the present invention can significantly reduce the axial size of the mode converter while ensuring that the mode converter has a wider working bandwidth and higher power capacity. The axial size of the present invention is less than 4 times the working wavelength, and the relative working 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 chamfered or right-angled, which can 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 "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 diagram of the structure 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 nth polarization twisted waveguide. Figure 2 (b) is the top view of the nth 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 nth polarization twisted waveguide along the GG' section;

[0022] Figure 3 A compact broadband circular waveguide TM 01 -TE 013D view of the mode converter;

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

[0024] Figure 5 for Figure 4 Medium Circular WaveguideTM 01 Structural diagram 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 A 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 a 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 A cross-sectional view of the mode synthesizer along the BB' plane;

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

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

[0029] The technical solution of the present invention is further described in detail below in conjunction with 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 waveguide TM 01 -TE 01The mode converter consists of a circular waveguide TM 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 01 The mode synthesizer 3 is composed of three parts connected coaxially in sequence, wherein OO' is 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 rotation symmetrical layout along the central axis OO', and its axial length is l. Definition of circular waveguide TM 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 of the 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 is composed 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 r 0 , axial length is 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 outer end surface of the first disk waveguide 13 is connected to the H-plane disk-shaped output structure 14, and the radius of the outer end surface is r 1 The H-plane disc-shaped 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 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 (such as Figure 5 (a)). The bottom length of the wide side of the nth trapezoidal waveguide is a 1 =2r 1 sin(θ / 2), the top length of the broad side is a 0 , the narrow side length is b 0 , radial length is d 1 The length of the wide side of the nth rectangular waveguide is equal to a 0 , the narrow side length is equal to b 0 , height l 1 The truncated cone-shaped 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 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 surface of the first disk waveguide 13. The truncated cone matching structure 15 is composed of a top truncated cone 151, a middle cylinder 152, and a bottom truncated cone 153 coaxially connected from left to right, and their wall thickness is equal to t. The top truncated cone 151 is a hollow truncated cone with a bottom at the left end, and the radius of the left end surface 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 truncated 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, and the outer radius of the left end is 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 circular waveguide 13. The first arc chamfered structure 12 and the truncated cone matching structure 15 play a role in impedance matching between the input circular waveguide 11 and the first circular waveguide 13. The top truncated cone 151 can 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 in-phase H-plane rectangular waveguide TE through the synergistic effect of the first arc chamfer structure 12, the bottom truncated cone 153 and the first disk waveguide 13. 10 Efficient mode conversion.

[0032] like Figure 6 As shown, combined Figure 8The 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 curved waveguide 2n1, a first rectangular waveguide 2n2, and a second E-plane rectangular curved waveguide 2n3 connected in sequence. The first E-plane rectangular curved waveguide 2n1 consists of a section of length l 2 The second rectangular waveguide 2n11 and a 90°E-plane rectangular bend waveguide 2n12 are connected in sequence. The second rectangular waveguide 2n11 is used as the input end and 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. To ensure that the 90° E-plane rectangular bend waveguide 2n12 has a high power capacity and a compact structure, as Figure 6 As shown in (b), the inner side of the 90°E-plane rectangular curved waveguide 2n12 is chamfered with a circular arc, and the outer side is chamfered with a triangular arc. The radius of the inner circular arc chamfer is r b3 , the length of the outer longitudinal cutting angle is c 1 , the length of the transverse cutting angle is c 2 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 input end of the first rectangular waveguide 2n2 is at a distance d from the central axis OO'. The bottom of the first rectangular waveguide 2n2 is closed, and a rectangular opening 2n4 (such as Figure 6 (c) shows 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 of the 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 angle. The radius of the inner circular arc chamfer is r b4 The lengths of the outer cutting angles are c 3 、c 4 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 width of the third rectangular waveguide 2n32 is equal to a 0 , the narrow side length is equal to b 0 , the length is l 4 . Combined Figure 6 (d), 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. 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 01The 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 size of the E-plane curved waveguide 2n31 needs to meet the following requirements:

[0033]

[0034] r b5 =r b6 +b 0 , d=r 1 +d 1 +l 1 +l 2 +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-surface curved waveguide 2n31 are both small, resulting in poor transmission characteristics of the E-surface curved waveguide 2n31, affecting the working bandwidth of the entire mode converter; and when the ψ angle is too large, the adjacent rectangular waveguide polarization bending structures will overlap. Therefore, ψ is generally set to 20°~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 r. 2 , axial length is 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 surface of the second disk waveguide 33 is connected to the E-plane disk-shaped input structure 34, and the radius of the outer end surface is r 3 The E-plane disk-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 01The 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 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 length of the bottom of the narrow side of the nth trapezoidal waveguide is 2r 3 sin(θ / 2), the top length of the narrow side is b 0 , width length a 0 , radial length is d 2 The width of the nth rectangular waveguide 34n2 is equal to a 0 , the narrow side length is equal to b 0 , height l 5 .like Figure 7 As shown in (b), the conical matching structure 35 is located in the circular waveguide TE 01 The left end of the synthesizer 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 opening at the left end, and its thickness is equal to t, and the radius of the opening at the left end is c. 6 , the axial length is c 5 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 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 r 1 >r 0 >0,r 3 >r 2 >0,a 0 >b 0 >0,r e3 >r e2 >r e1 >0,r 0 Equivalent to external TM 01 Inner radius of the high power microwave circular waveguide, r 2 Equal to the external TE 01 The inner radius of the high-power microwave circular waveguide. t is usually 2 to 5 mm.

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

[0039] First, high-power microwaves are produced in circular waveguides TM01 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 microwaves are gradually converted into the coaxial TEM mode. Through the synergistic effect of the first arc chamfer structure 12 and the bottom truncated cone 153, the coaxial TEM mode microwaves are converted into N-channel 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 Conversion of mode microwave polarization direction to 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 identically structured 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 10 After the mode microwave, the synergistic effect of the second arc chamfer structure 32 and the conical matching structure 35 realizes N-way equal amplitude and same phase E-plane rectangular waveguide TE 10 Mode to circular waveguide TE 01 Efficient synthesis of modes, completing the 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 microwave wavelength range 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 One embodiment of the mode converter has specific design dimensions:

[0044] According to the application scenario, input the radius r of the circular waveguide 11 0 is 23.5 mm, and the radius r of the output circular waveguide 31 is2 According to the mode converter requirements, 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 and staggered along the central axis by 23°, that is, ψ = 23°. According to the aforementioned size requirements of the mode converter, the main parameters of the mode converter are obtained by optimizing the electromagnetic simulation software CST Studio Suit after preliminary selection, as shown in Table 1.

[0045] Table 1

[0046] Structural parameters Dimensions (mm) Structural parameters Dimensions (mm) Structural parameters Dimensions (mm) <![CDATA[r 1 ]]> 35.5 <![CDATA[l e3 ]]> 9.6 <![CDATA[l 3 ]]> 20.2 <![CDATA[r 3 ]]> 32 <![CDATA[r b1 ]]> 4 <![CDATA[l 4 ]]> 2 <![CDATA[a 0 ]]> 24 <![CDATA[r b2 ]]> 3 <![CDATA[l 5 ]]> 2.3 <![CDATA[b 0 ]]> 11 <![CDATA[r b3 ]]> 6 <![CDATA[c 1 ]]> 10.5 <![CDATA[L in ]]> 10 <![CDATA[r b4 ]]> 4 <![CDATA[c 2 ]]> 10.5 <![CDATA[r e1 ]]> 6.6 <![CDATA[r b7 ]]> 6 <![CDATA[c 3 ]]> 15.8 <![CDATA[r e2 ]]> 12 <![CDATA[d 1 ]]> 12 <![CDATA[c 4 ]]> 15.8 <![CDATA[r e3 ]]> 21.6 <![CDATA[d 2 ]]> 20 <![CDATA[c 5 ]]> 20 <![CDATA[l e1 ]]> 9.6 <![CDATA[l 1 ]]> 4 <![CDATA[c 6 ]]> 20 <![CDATA[l e2 ]]> 14.6 <![CDATA[l 2 ]]> 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 8 It can be seen that in the frequency range of 8.53-10.13GHz, the reflection coefficient of Example 1 is less than -16dB, and the transmission coefficient is greater than -0.10dB, indicating that in the frequency range of 8.53-10.13GHz, the mode conversion efficiency of Example 1 is greater than 98%; and in the frequency range of 8.50-10.85GHz, the reflection coefficient of Example 1 is less than -15dB, and the transmission coefficient is greater than -0.15dB, indicating that in the frequency range of 8.50-10.85GHz, 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 +fmin )×100%,f min =8.50GHz, f max =10.85GHz) or above.

[0048] Fig. 9 The simulation results of the electric field distribution characteristics of Example 1 at a central operating frequency of 9.6 GHz when the input microwave power is 0.5 W are shown. Fig. 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. Fig. 9 It can be seen that Example 1 can effectively realize the circular waveguide TM 01 Mode-TE 01 The maximum electric field amplitude E on the right side 0.5W 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 working 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 waveguideTM 01 -TE 01 mode converter, characterized in that Compact Broadband Circular WaveguideTM 01 -TE 01 The mode converter consists of a circular waveguide TM 01 A 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 of the high-power microwave mode is a compact broadband circular waveguide TM 01 -TE 01 Mode converter input, i.e. Compact Broadband Circular WaveguideTM 01 -TE 01 Mode converter left end, circular waveguide TE 01 The output of the high-power microwave mode is a compact broadband circular waveguide TM 01 -TE 01 Output of the mode converter, the Compact Broadband Circular WaveguideTM 01 -TE 01 Right side 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 The 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 circular 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 circular 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 surface of the first disk waveguide (13) is connected to the H-plane disk-shaped output structure (14), and the radius of the outer end surface is r1; the H-plane disk-shaped 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 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 circular arc chamfer structure (12), and the first disk waveguide (13), and is connected to the inner right end surface of the first disk waveguide (13); the truncated cone matching structure (15) is composed of a top truncated cone (151), a middle cylinder (152), and a bottom truncated cone (153) which are coaxially connected in sequence from left to right, and their wall thicknesses are all equal to t; wherein the top truncated cone (151) is a hollow truncated cone with a bottom at the left end, and the radius of the left end surface 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 truncated 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, and the outer radius of the left end is 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-channel equal-amplitude and same-phase H-plane rectangular waveguide TE through the synergistic effect of the first arc chamfer structure (12), the bottom truncated cone (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 curved waveguide (2n1), a first rectangular waveguide (2n2) and a second E-plane rectangular curved waveguide (2n3) connected in sequence; the first E-plane rectangular curved waveguide (2n1) is composed of a second rectangular waveguide (2n11) with a length of l2 and a 90° E-plane rectangular curved waveguide (2n12) connected in sequence; the second rectangular waveguide (2n11) is used as an input end and connected to a 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) is chamfered with a circular arc, and the outer side is chamfered with a triangular angle; the radius of the inner circular 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 curved 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 inside the bottom, so that the transmission direction of the microwave is bent 90° along the inside of the H plane; the inside of the bottom of the first rectangular waveguide (2n2) is chamfered with an arc, and the outside is chamfered with a triangular angle; the radius of the inner arc chamfer is r b4 , the lengths of the outer cut corners 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 curved waveguide (2n3); the second E-plane rectangular curved waveguide (2n3) is composed of an E-plane curved waveguide (2n31) and a third rectangular waveguide (2n32) connected in sequence; the inner arc radius of the E-plane 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; 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 circular arc chamfer 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 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 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 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 (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 opening at the left end, the thickness of which is equal to t, the radius of the opening at the left end is c6, and the axial length is 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 synthesizers are 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 TM 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 TM as claimed in claim 1 01 -TE 01 mode converter, characterized in that The Circular WaveguideTM 01 A 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 TM 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 TM 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 2 to 5 mm.

6. A compact broadband circular waveguide TM as claimed in claim 1 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 mode 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 TM as claimed in claim 1 01 -TE 01 mode converter, characterized in that The electromagnetic simulation software is CST Studio Suit 2014 version.

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