Full-bandwidth terminating rectangular waveguide coaxial conversion device

Abstract

The invention belongs to the technical field of electromagnetic fields and microwaves, and discloses a full-bandwidth terminating rectangular waveguide coaxial conversion device which is realized by adopting a mode that a coaxial inner conductor and a coaxial outer conductor are separated from each other, and a rectangular waveguide body, a second-order rectangular step metal structure and the coaxial inner conductor are of an integrated processing structure. Secondary assembly of the coaxial inner conductor and the second-order rectangular stepped metal structure is avoided, and secondary assembly errors are eliminated; according to the device, the coaxial outer conductor and the cut-off flange are integrally machined, the whole device only needs one-time assembly, namely assembly of the waveguide flange and the cut-off flange, and errors caused by multiple times of assembly are greatly reduced; the diameter of the coaxial inner conductor is uniform, a fine boss structure does not exist, the machining difficulty is greatly reduced, meanwhile, the coaxial inner conductor of the device does not need to be supported by a medium, the whole waveguide coaxial conversion device is of an all-metal structure, and the cost is low. And assembly errors and influences caused by a medium support material in traditional waveguide coaxial conversion are further avoided.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic field and microwave technology, specifically relating to a full-bandwidth terminated rectangular waveguide coaxial conversion device, used to improve the conversion efficiency of full-bandwidth rectangular waveguide to coaxial mode and achieve full-bandwidth operation. Background Technology

[0002] Currently, waveguide-coaxial converters are a widely used key conversion structure in various microwave and millimeter-wave systems, especially in waveguide-based active phased array antenna systems, where they are often used to achieve signal interconnection between waveguide array antennas and transceiver modules. With the development of phased array radar, higher requirements have been placed on the operating bandwidth, size, and insertion loss of waveguide-coaxial converters. Currently, waveguide-coaxial converters are mainly divided into two categories according to the coaxial feeding method: (1) orthogonal feeding type, that is, the coaxial probe is perpendicular to the wide side of the waveguide for feeding; (2) termination feeding type, that is, the coaxial probe and the waveguide transmission direction are on the same axis for feeding.

[0003] The principle of the orthogonally fed waveguide coaxial converter is to insert a coaxial probe into a rectangular waveguide cavity, coupling the energy transmitted along the coaxial line into the waveguide cavity via the probe, thus exciting the TE10 master mode in the waveguide (e.g., patent CN 107742766B). Since one end of the waveguide port is a short-circuit plate, electromagnetic energy can only be transmitted towards the other port. To achieve good matching of the waveguide coaxial converter over a wide frequency range, existing methods include adjusting the insertion depth and radius of the probe, or using a gradient structure at the probe tip to broaden the bandwidth. Additional matching structures are also used to achieve wideband matching. However, these methods complicate fabrication and assembly, requiring dielectric support for probe fixation to excite the TE10 master mode in the rectangular waveguide. The input and output ports of this orthogonally fed structure are not on the same horizontal line, which is detrimental to system cascading and results in a less compact structure.

[0004] The main purpose of the patent (CN107742766B) is to realize the direct transition from coaxial connector to elliptical waveguide. It mainly uses elliptical waveguide matching grooves to realize the transformation from the TE10 master mode of rectangular waveguide to the working mode of elliptical waveguide, without involving how to broaden the working bandwidth of microwave devices.

[0005] The principle of the terminated-feed waveguide coaxial converter is to insert a coaxial probe into the waveguide cavity through the short-circuit wall of a rectangular waveguide to excite the TE10 master mode in the rectangular waveguide. To achieve good impedance matching over a wide frequency range, multi-section impedance transformers are currently mainly used to adjust the waveguide impedance value, matching the characteristic impedance of the rectangular waveguide with that of the coaxial line, thus achieving low-loss signal transmission (e.g., patent CN 111600106 A). However, multi-section impedance transformers are complex to design, requiring the multi-section impedance transformation structure to follow specific rules (generally Chebyshev's law). Furthermore, the fabrication and assembly of multi-section impedance transformation structures are highly demanding, and the coaxial probe needs to be welded to the waveguide impedance structure, further increasing the complexity of fabrication and assembly.

[0006] The main problem addressed by patent CN 111600106 A is overcoming assembly errors and improving the standing wave performance of waveguide-coaxial converters. Its method involves providing a matching boss on the inner conductor of the coaxial converter, forming a gap with the inner sidewall of the waveguide end face. The inner conductor and the impedance matching block are connected via screws through a central jack. The matching boss on the inner conductor and the impedance matching block work together to achieve the matching function. This waveguide-coaxial converter uses a three-step impedance matching block, and the matching structure requires multiple assembly steps due to the screw connection. Assembly errors also exist in the assembly of the inner conductor and the impedance matching block, and the conductor within the waveguide also requires dielectric support.

[0007] Based on the above issues, the development of a full-bandwidth, integrated fabrication, all-metal low-loss waveguide coaxial converter that does not require secondary assembly or dielectric support has great market potential. Summary of the Invention

[0008] This invention addresses the wideband requirements of coaxial converters for terminated rectangular waveguides and the issues of reducing the difficulty of fine processing and assembly complexity. It proposes an all-metal wideband coaxial converter for terminated waveguides with independent inner and outer conductors in a coaxial feed structure, which effectively reduces the difficulty of the entire processing and assembly, and can be assembled in a single installation.

[0009] To solve the above technical problems, the technical solution of the present invention is: a full-bandwidth terminated rectangular waveguide coaxial conversion device, comprising a rectangular waveguide, a stepped matching structure, a waveguide flange, a cut-off flange, a coaxial outer conductor, a coaxial inner conductor, and fastening screws; The rectangular waveguide is a standard rectangular waveguide with openings on both sides. A waveguide flange is integrally formed and disposed at one end of the rectangular waveguide, and the cross-section of the waveguide flange is flush with the port of the rectangular waveguide. The other end of the rectangular waveguide is an open structure. The stepped matching structure is integrally formed and disposed on the center line of the bottom of the waveguide cavity at the end of the rectangular waveguide where the waveguide flange is mounted, and a gap of 0.5~1mm is left between the outer side of the stepped matching structure and the port plane of the rectangular waveguide. The cutoff flange and the waveguide flange are fastened with fastening screws. A circular through hole is opened in the center of the cutoff flange. The coaxial inner conductor passes through the circular through hole of the cutoff flange and is integrally formed with the stepped matching structure. The central axis of the coaxial inner conductor is coaxial with the central axis of the circular through hole. The coaxial outer conductor is integrally formed and set on the outside of the cutoff flange. The central axis of the coaxial outer conductor is coaxial with the central axis of the circular through hole. The coaxial inner conductor is located inside the coaxial outer conductor to form a coaxial waveguide structure.

[0010] Preferably, the waveguide flange is a standard rectangular waveguide flange with a first mounting through hole, through which fastening screws pass to fasten the stop flange and the waveguide flange.

[0011] Preferably, the stepped matching structure is a two-order rectangular stepped metal structure, including an integrally formed first step and a second step. The first step and the second step have the same width. The first step is close to the waveguide flange and is higher than the second step. There is a gap between the first step and the port of the rectangular waveguide where the waveguide flange is provided. The stepped matching structure is located on the center line of the wide side of the bottom surface of the waveguide cavity of the rectangular waveguide. The stepped matching structure and the rectangular waveguide are integrally processed structures.

[0012] Preferably, the size of the stop flange is the same as that of the waveguide flange, and the size and position of the second mounting through hole opened around the stop flange are the same as the size and position of the first mounting through hole on the waveguide flange. The stop flange covers the waveguide flange, and the fastening screws pass through the first mounting through hole and the second mounting through hole to fasten the stop flange and the waveguide flange together to achieve electrical connection.

[0013] Preferably, the coaxial inner conductor is a metal cylinder. One end of the coaxial inner conductor passes through a circular through hole in the center of the stop flange and is rigidly connected to the first step side of the stepped matching structure to form an integrated structure. The other end of the coaxial inner conductor is a flower-shaped opening structure that matches the center probe of the J-type coaxial connector.

[0014] Preferably, the coaxial outer conductor is a cylindrical structure, and the inner diameter of the coaxial outer conductor is the same as the diameter of the circular through hole of the stop flange. One end of the coaxial outer conductor is integrally formed and disposed on the outside of the stop flange. The central axis of the coaxial outer conductor is coaxial with the central axis of the circular through hole, and the central axis of the coaxial outer conductor is also coaxial with the central axis of the coaxial inner conductor. The other end of the coaxial outer conductor is provided with a threaded structure to match the nut structure of the K-type coaxial connector.

[0015] Preferably, the coaxial inner conductor and the coaxial outer conductor constitute an air-filled coaxial waveguide structure. The ratio of the diameter of the coaxial inner conductor to the inner diameter of the coaxial outer conductor matches the ratio of the inner and outer diameters of a 50Ω coaxial cable. The port of the coaxial outer conductor with a threaded structure and the port of the coaxial inner conductor with a flower-shaped opening structure constitute a K-type coaxial connector. The K-type coaxial connector matches a J-type coaxial connector.

[0016] The rectangular waveguide is a BJ-260 standard rectangular waveguide with openings on both sides. The waveguide cavity dimensions are 8.636mm × 4.318mm, the waveguide wall thickness is 2mm, and the main mode coverage range of the BJ-260 standard rectangular waveguide is 21.7~33GHz.

[0017] Compared with the prior art, the advantages of the present invention are as follows: (1) The present invention discloses a coaxial converter for terminating full-bandwidth waveguides, which is realized by the integrated processing of a rectangular waveguide, a second-order rectangular stepped metal structure and a coaxial inner conductor. It eliminates the need for secondary assembly of the coaxial inner conductor and the second-order rectangular stepped metal structure, thus eliminating the assembly error caused by secondary assembly. At the same time, the diameter of the coaxial inner conductor of the present invention is uniform and there is no fine boss structure, which greatly reduces the processing difficulty. (2) The waveguide coaxial conversion device of the present invention adopts a second-order rectangular stepped metal structure instead of the traditional third-order impedance structure, which reduces the mutual influence between the second-order steps and effectively realizes wideband operation. (3) The coaxial outer conductor and the stop flange of the waveguide coaxial conversion device of the present invention are processed as a whole. The entire termination waveguide coaxial conversion device only needs to be assembled once, that is, the assembly of the rectangular waveguide flange and the stop flange can be completed, which greatly reduces the error and impact caused by multiple assemblies. (4) The coaxial inner conductor and coaxial outer conductor of the present invention are separated from each other, which effectively reduces the difficulty of the entire assembly. Moreover, since the inner and outer structures are integrated, no additional external fastening structure is required, which effectively reduces the difficulty of processing and assembly and the complexity of the port. (5) The coaxial inner conductor of the waveguide coaxial conversion device of the present invention does not require dielectric support, and the entire waveguide coaxial conversion device is an all-metal structure, which further avoids the assembly error and influence caused by the dielectric support material in the traditional waveguide coaxial conversion. Attached Figure Description

[0018] Figure 1 A schematic diagram of the composition structure of a full-bandwidth terminated rectangular waveguide coaxial converter according to the present invention; Figure 2 A schematic diagram of the left side of a full-bandwidth terminated rectangular waveguide coaxial converter according to the present invention; Figure 3 A schematic diagram of the right side of a full-bandwidth terminated rectangular waveguide coaxial converter according to the present invention; Figure 4 The simulation results of the S-parameters of the full-bandwidth terminated rectangular waveguide coaxial converter of the present invention are shown in the figure.

[0019] Explanation of reference numerals in the attached figures: 1. Rectangular waveguide; 2. Stepped matching structure; 3. Waveguide flange; 4. Cut-off flange; 5. Coaxial outer conductor; 6. Coaxial inner conductor; 7. Fastening screws. 2-1, First step; 2-2, Second step; 3-1. First mounting through hole; 4-1, Circular through hole; 4-2, Second mounting through hole. Detailed Implementation

[0020] The specific implementation of the present invention is described below with reference to embodiments: It should be noted that the structures, proportions, sizes, etc. shown in this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0021] This invention utilizes the characteristic that ridge waveguides and rectangular waveguides, under the same cross-section, can achieve a wider single-mode operating bandwidth. It converts the TEM mode of the coaxial line into the dominant mode of the ridge waveguide, and then uses a second-order rectangular stepped metal structure to achieve wideband matching between the ridge waveguide dominant mode and the rectangular waveguide TE10 dominant mode, thus realizing wideband conversion from the coaxial line TEM mode to the rectangular waveguide TE10 dominant mode, achieving the goal of full-bandwidth coaxial conversion with a terminated rectangular waveguide. The all-metal structure can significantly reduce the reflection coefficient across the entire waveguide bandwidth, effectively reducing insertion loss and significantly improving energy conversion efficiency.

[0022] Example 1 like Figures 1-3 As shown, the present invention proposes a full-bandwidth terminated rectangular waveguide coaxial conversion device, including a rectangular waveguide 1, a stepped matching structure 2, a waveguide flange 3, a cut-off flange 4, a coaxial outer conductor 5, a coaxial inner conductor 6, and fastening screws 7; The rectangular waveguide 1 is a standard rectangular waveguide with openings on both sides. The waveguide flange 3 is integrally formed and disposed at one end of the rectangular waveguide 1, and the cross-section of the waveguide flange 3 is flush with the port of the rectangular waveguide 1. The other end of the rectangular waveguide 1 is an open structure. The stepped matching structure 2 is integrally formed and disposed on the center line of the bottom of the waveguide cavity at the end of the rectangular waveguide 1 where the waveguide flange 3 is installed, and a gap of 0.5~1mm is left between the outer side of the stepped matching structure 2 and the port plane of the rectangular waveguide 1. The cutoff flange 4 and the waveguide flange 3 are fastened together by fastening screws 7. A circular through hole 4-1 is opened in the center of the cutoff flange 4. The coaxial inner conductor 6 passes through the circular through hole 4-1 of the cutoff flange 4 and is integrally formed with the stepped matching structure 2. The central axis of the coaxial inner conductor 6 is coaxial with the central axis of the circular through hole 4-1. The coaxial outer conductor 5 is integrally formed and disposed on the outside of the cutoff flange 4. The central axis of the coaxial outer conductor 5 is coaxial with the central axis of the circular through hole 4-1. The coaxial inner conductor 6 is located inside the coaxial outer conductor 5 to form a coaxial waveguide structure.

[0023] All components of this invention are metal structures. The all-metal structure can significantly reduce the reflection coefficient within the entire waveguide bandwidth, effectively reduce insertion loss, and effectively improve energy conversion efficiency.

[0024] Example 2 Preferred, such as Figures 1-2 As shown, the waveguide flange 3 is a standard rectangular waveguide flange with a first mounting through hole 3-1. The fastening screw 7 passes through the first mounting through hole 3-1 to fasten the stop flange 4 and the waveguide flange 3.

[0025] Preferred, such as Figure 1 As shown, the stepped matching structure 2 is a two-order rectangular stepped metal structure, including an integrally formed first step 2-1 and second step 2-2. The width of the first step 2-1 and the second step 2-2 is the same. The first step 2-1 is close to the waveguide flange 3 and is higher than the second step 2-2. There is a gap between the first step 2-1 and the port of the rectangular waveguide 1 where the waveguide flange 3 is provided. The stepped matching structure 2 is located on the center line of the wide side of the bottom surface of the waveguide cavity of the rectangular waveguide 1. The stepped matching structure 2 and the rectangular waveguide 1 are an integral structure.

[0026] The two steps of the stepped matching structure 2 have the same width. The height of the step closer to the waveguide opening is higher than that of the step closer to the waveguide opening. The side of the higher step closer to the waveguide opening has a gap of 0.5~1mm with the waveguide opening.

[0027] Example 3 Preferred, such as Figure 1As shown, the size of the stop flange 4 is the same as that of the waveguide flange 3. The size and position of the second mounting through hole 4-2 opened around the stop flange 4 are the same as the size and position of the first mounting through hole 3-1 on the waveguide flange 3. The stop flange 4 covers the waveguide flange 3. The fastening screw 7 passes through the first mounting through hole 3-1 and the second mounting through hole 4-2 to fasten the stop flange 4 and the waveguide flange 3 together to achieve electrical connection.

[0028] The waveguide flange 3 has a first mounting through hole 3-1, which facilitates fastening connection with other waveguide flanges of the same frequency band, and the cross section of the waveguide flange 3 is flush with the port of the rectangular waveguide 1.

[0029] Example 4 Preferred, such as Figures 1-3 As shown, the coaxial inner conductor 6 is a metal cylinder. One end of the coaxial inner conductor 6 passes through the circular through hole 4-1 in the center of the stop flange 4 and is rigidly connected to the side of the first step 2-1 of the stepped matching structure 2 to form an integrated structure. The other end of the coaxial inner conductor 6 is a flower-shaped opening structure, which matches the center probe of the J-type coaxial connector.

[0030] Preferred, such as Figure 1 , 3 As shown, the coaxial outer conductor 5 is a cylindrical structure. The inner diameter of the coaxial outer conductor 5 is the same as the diameter of the circular through hole 4-1 of the stop flange 4. One end of the coaxial outer conductor 5 is integrally formed on the outside of the stop flange 4. The central axis of the coaxial outer conductor 5 is coaxial with the central axis of the circular through hole 4-1. At the same time, the central axis of the coaxial outer conductor 5 is also coaxial with the central axis of the coaxial inner conductor 6. The other end of the coaxial outer conductor 5 is provided with a threaded structure, which matches the nut structure of the K-type coaxial connector.

[0031] Preferred, such as Figure 1 , 3 As shown, the coaxial inner conductor 6 and the coaxial outer conductor 5 constitute an air-filled coaxial waveguide structure. The ratio of the diameter of the coaxial inner conductor 6 to the inner diameter of the coaxial outer conductor 5 matches the ratio of the inner and outer diameters of a 50Ω coaxial cable. The port of the coaxial outer conductor 5 with a threaded structure and the port of the coaxial inner conductor 6 with a flower-shaped opening structure constitute a K-type (female) coaxial connector. The K-type coaxial connector matches a J-type (male) coaxial connector.

[0032] In this invention, the coaxial inner conductor 6 and the coaxial outer conductor 5 are separated from each other, which effectively reduces the difficulty of the entire assembly. Moreover, since the inner and outer structures are integrated, no additional external fastening structures are required, which effectively reduces the difficulty of assembly and port complexity.

[0033] Example 5 This embodiment designs a coaxial converter with a terminated rectangular waveguide operating in the Ka band, based on a specific implementation method. For example... Figure 1 As shown, the coaxial converter with a rectangular waveguide termination mainly includes a rectangular waveguide 1, a stepped matching structure 2, a waveguide flange 3, a cut-off flange 4, a coaxial outer conductor 5, a coaxial inner conductor 6, and fastening screws 7.

[0034] like Figure 2 As shown, the rectangular waveguide 1 is a BJ-260 standard rectangular waveguide with openings on both sides. The waveguide cavity dimensions are 8.636mm × 4.318mm, and the waveguide wall thickness is 2mm. The TE10 master mode coverage range of the BJ-260 standard rectangular waveguide is 21.7~33GHz. The waveguide flange 3 is located at one end of the BJ-260 standard rectangular waveguide, and the waveguide flange 3 is a BJ-260 standard flange. The second-order stepped matching structure 2 is located on the centerline of the bottom wide side of the waveguide cavity at the end of the rectangular waveguide 1 with the waveguide flange 3. The coaxial inner conductor 6 passes through the circular through hole 4-1 in the center of the cutoff flange 4 and is rigidly connected to the side of the stepped matching structure 2 near the waveguide opening, forming an integrated structure.

[0035] like Figure 3 As shown, the coaxial outer conductor 5 is a cylindrical structure with an inner diameter that is the same as the diameter of the circular through hole 4-1 of the stop flange 4. One end of the coaxial outer conductor 5 is installed on the outside of the stop flange 4 and is coaxial with the central axis of the coaxial inner conductor 6, forming a 50Ω air-filled coaxial waveguide. The coaxial inner conductor 6 has a diameter of 1.27mm and is matched with the K-connector.

[0036] like Figure 4 The simulation results of this embodiment are shown in the figure. In this embodiment, the rectangular waveguide 1 adopts the BJ-260 standard rectangular waveguide, and its main mode operating frequency band is 21.7~33GHz. In this embodiment, the coaxial port (the port formed by the coaxial outer conductor 5 and the coaxial inner conductor 6) is a port 1, and the waveguide port (such as...) Figure 1 As shown, the left port of rectangular waveguide 1 is a 2-port. According to simulation results, the coaxial converter designed in this embodiment with a terminated rectangular waveguide has a working bandwidth of 19.3~36GHz with S11≤-10dB as a reference, and 20.3~34.2GHz with S11≤-15dB as a reference, effectively covering the main mode working range of the BJ-260 standard rectangular waveguide. Therefore, the coaxial converter designed in this embodiment with a terminated rectangular waveguide can operate across the entire bandwidth. Since this coaxial converter with a terminated rectangular waveguide has an all-metal structure, it has very low insertion loss. According to simulation results, within the working frequency band (20.3~34.2GHz), the insertion loss of this coaxial converter with a terminated rectangular waveguide is... ≤0.14dB, with low insertion loss, close to 0.

[0037] The problem this invention aims to solve is reducing assembly errors and insertion losses in terminated rectangular waveguide co-conversion, thereby achieving wideband operation of the terminated rectangular waveguide co-conversion. This invention employs a second-order matching structure to achieve wideband matching from the coaxial waveguide master mode to the rectangular waveguide TE10 master mode, thus enabling full-band operation. The working principle of this invention is as follows: This invention addresses the bandwidth requirements of coaxial converters for terminated rectangular waveguides by proposing a full-bandwidth coaxial converter for terminating rectangular waveguides. The device mainly comprises a rectangular waveguide 1, a stepped matching structure 2, a waveguide flange 3, a stop flange 4, a coaxial outer conductor 5, a coaxial inner conductor 6, and fastening screws 7. The rectangular waveguide 1 is a rectangular waveguide with openings on both sides. One side of the waveguide is connected to the stop flange 4 via the waveguide flange 3. A coaxial outer conductor 5 for a coaxial connector is located outside the stop flange 4, with the coaxial connector's axis perpendicular to the stop flange 4. The stepped matching structure 2 is located on the center line of the wide side of the bottom of the waveguide cavity and is a certain distance from the stop flange 4. A circular through-hole 4-1 is opened in the center of the stop flange 4, through which the coaxial inner conductor 6 of the coaxial connector passes rigidly and is connected to the stepped matching structure 2. The coaxial waveguide converter of the present invention adopts a design that separates the inner and outer conductors of the coaxial structure. The stepped matching structure 2 and the inner coaxial conductor 6 are integrally processed in the waveguide cavity, and the cut-off flange 4 and the outer coaxial conductor 5 are integrally processed, so that the outer coaxial conductor 5 and the inner coaxial conductor 6 are independent of each other. Only one assembly is required (i.e., the assembly of the waveguide flange 3 and the cut-off flange 4), which effectively reduces the error and assembly difficulty caused by multiple assemblies. At the same time, the all-metal structure reduces insertion loss and effectively improves the energy conversion efficiency of the rectangular waveguide coaxial converter.

[0038] This invention discloses a coaxial converter for terminating full-bandwidth waveguides, which is achieved by integrating a rectangular waveguide, a second-order rectangular stepped metal structure, and a coaxial inner conductor. This eliminates the need for secondary assembly of the coaxial inner conductor and the second-order rectangular stepped metal structure, thus eliminating secondary assembly errors. At the same time, the coaxial inner conductor of this invention has a uniform diameter and does not have a fine boss structure, which greatly reduces the processing difficulty.

[0039] The waveguide coaxial converter of this invention uses a second-order rectangular stepped metal structure to replace the traditional third-order impedance structure, which reduces the matching effect between the second-order steps and realizes full-band operation.

[0040] The coaxial outer conductor and the stop flange of the waveguide coaxial conversion device of the present invention are processed as a single unit. The entire termination waveguide coaxial conversion device only needs to be assembled once, that is, the assembly of the rectangular waveguide flange and the stop flange, which greatly reduces the error caused by multiple assembly.

[0041] In this invention, the inner and outer coaxial conductors are separated, which effectively reduces the difficulty of the entire assembly. Moreover, since the inner and outer structures are integrated, no additional external fastening structures are required, which effectively reduces the difficulty of assembly and port complexity.

[0042] The coaxial inner conductor of the waveguide coaxial converter of the present invention does not require dielectric support, and the entire waveguide coaxial converter is an all-metal structure, further avoiding the assembly errors and effects caused by dielectric support materials in traditional waveguide coaxial converters.

[0043] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

[0044] Many other changes and modifications can be made without departing from the concept and scope of this invention. It should be understood that this invention is not limited to the specific embodiments, and the scope of this invention is defined by the appended claims.

Claims

1. A full-bandwidth terminated rectangular waveguide coaxial converter, characterized in that: It includes a rectangular waveguide (1), a stepped matching structure (2), a waveguide flange (3), a stop flange (4), a coaxial outer conductor (5), a coaxial inner conductor (6), and fastening screws (7); The rectangular waveguide (1) is a standard rectangular waveguide with openings on both sides. The waveguide flange (3) is integrally formed and disposed at one end of the rectangular waveguide (1), and the cross section of the waveguide flange (3) is flush with the port of the rectangular waveguide (1). The other end of the rectangular waveguide (1) is an open structure. The stepped matching structure (2) is integrally formed and disposed on the center line of the bottom of the waveguide cavity at the end of the rectangular waveguide (1) where the waveguide flange (3) is installed. A gap of 0.5~1mm is left between the outer side of the stepped matching structure (2) and the port plane of the rectangular waveguide (1). The stop flange (4) and the waveguide flange (3) are fastened by fastening screws (7). The stop flange (4) has a circular through hole (4-1) in the center. The coaxial inner conductor (6) passes through the circular through hole (4-1) of the stop flange (4) and is integrally formed with the stepped matching structure (2). The central axis of the coaxial inner conductor (6) is coaxial with the central axis of the circular through hole (4-1). The coaxial outer conductor (5) is integrally formed and set on the outside of the stop flange (4). The central axis of the coaxial outer conductor (5) is coaxial with the central axis of the circular through hole (4-1). The coaxial inner conductor (6) is located inside the coaxial outer conductor (5) to form a coaxial waveguide structure.

2. The full-bandwidth terminated rectangular waveguide coaxial converter according to claim 1, characterized in that: The waveguide flange (3) is a standard rectangular waveguide flange. The waveguide flange (3) has a first mounting through hole (3-1). The fastening screw (7) passes through the first mounting through hole (3-1) to fasten the stop flange (4) and the waveguide flange (3).

3. The full-bandwidth terminated rectangular waveguide coaxial converter according to claim 1, characterized in that: The stepped matching structure (2) is a second-order rectangular stepped metal structure, including an integrally formed first step (2-1) and second step (2-2). The width of the first step (2-1) and the second step (2-2) is the same. The first step (2-1) is close to the waveguide flange (3). The first step (2-1) is higher than the second step (2-2). There is a gap between the first step (2-1) and the port of the rectangular waveguide (1) where the waveguide flange (3) is provided. The stepped matching structure (2) is located on the center line of the wide side of the bottom surface of the waveguide cavity of the rectangular waveguide (1). The stepped matching structure (2) and the rectangular waveguide (1) are integrally processed structures.

4. The full-bandwidth terminated rectangular waveguide coaxial converter according to claim 2, characterized in that: The size of the stop flange (4) is the same as that of the waveguide flange (3). The size and position of the second mounting through hole (4-2) opened around the stop flange (4) are the same as the size and position of the first mounting through hole (3-1) on the waveguide flange (3). The stop flange (4) covers the waveguide flange (3). The fastening screw (7) passes through the first mounting through hole (3-1) and the second mounting through hole (4-2) to fasten the stop flange (4) and the waveguide flange (3) together to achieve electrical connection.

5. The full-bandwidth terminated rectangular waveguide coaxial converter according to claim 3, characterized in that: The coaxial inner conductor (6) is a metal cylinder. One end of the coaxial inner conductor (6) passes through the circular through hole (4-1) in the center of the stop flange (4) and is rigidly connected to the side of the first step (2-1) of the stepped matching structure (2) to form an integrated structure. The other end of the coaxial inner conductor (6) is a flower-shaped opening structure that matches the center probe of the J-type coaxial connector.

6. The full-bandwidth terminated rectangular waveguide coaxial converter according to claim 1, characterized in that: The coaxial outer conductor (5) is a cylindrical structure. The inner diameter of the coaxial outer conductor (5) is the same as the diameter of the circular through hole (4-1) of the stop flange (4). One end of the coaxial outer conductor (5) is integrally formed and set on the outside of the stop flange (4). The central axis of the coaxial outer conductor (5) is coaxial with the central axis of the circular through hole (4-1). At the same time, the central axis of the coaxial outer conductor (5) is also coaxial with the central axis of the coaxial inner conductor (6). The other end of the coaxial outer conductor (5) is provided with a threaded structure, which matches the nut structure of the K-type coaxial connector.

7. A full-bandwidth terminated rectangular waveguide coaxial converter according to any one of claims 1 to 6, characterized in that: The coaxial inner conductor (6) and the coaxial outer conductor (5) constitute an air-filled coaxial waveguide structure. The ratio of the diameter of the coaxial inner conductor (6) to the inner diameter of the coaxial outer conductor (5) matches the ratio of the inner and outer diameters of a 50Ω coaxial cable. The port of the coaxial outer conductor (5) with a threaded structure and the port of the coaxial inner conductor (6) with a flower-shaped opening structure constitute a K-type coaxial connector. The K-type coaxial connector matches a J-type coaxial connector.

8. The full-bandwidth terminated rectangular waveguide coaxial converter according to claim 1, characterized in that: The rectangular waveguide (1) is a BJ-260 standard rectangular waveguide with openings on both sides.

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