The energy transmission structure of a high-power helical pulse traveling wave tube

Abstract

The present invention provides an energy transmission structure for a high-power helical pulse traveling-wave tube, which relates to the technical field of electro-vacuum devices. The energy transmission structure is composed of a waveguide structure, an impedance converter, a connecting piece, a conical coaxial window structure and an outer conductor; the impedance converter is installed inside the waveguide structure, and one end of the impedance converter is provided with a mounting hole, the connecting piece is installed in the mounting hole, the outer conductor is connected to one side of the waveguide structure, and one end of the connecting piece is arranged inside the outer conductor, the conical coaxial window structure is sleeved outside the connecting piece, and the conical coaxial window structure is sealed and connected inside the outer conductor; the present invention solves the problems of the withstand power capacity and reliability of the coupling structure for high-power output of the helical traveling-wave tube, realizes as small electromagnetic reflection as possible within the frequency band, ensures low-loss transmission, provides a reliable structure that can meet various test requirements, and enables its transmission characteristics to meet the usage requirements of high-power pulse traveling-wave tubes.

Description

Technical Field

[0001] The present invention belongs to the technical field of electro-vacuum devices, and more specifically, particularly relates to an energy transmission structure of a high-power helical pulse traveling wave tube. Background Art

[0002] Helical traveling wave tubes are widely used in fields such as radar, electronic countermeasures, and communication due to their advantages of high power, wide frequency band, high efficiency, and high gain. With the rapid development of weaponry and the requirement for long-range detection of radar, higher demands are placed on the output power of helical traveling wave tubes. The output power under the requirement of a large duty cycle will comprehensively test the performance and reliability of the product.

[0003] When designing the energy transmission structure, it is necessary to achieve as small a voltage standing wave ratio as possible within the frequency band to reduce the damage of electromagnetic reflection to the slow-wave circuit and energy transmission device of the traveling wave tube. At the same time, the coupling structure itself needs to have low loss and high-reliability structural characteristics to meet the requirements of the use and reliability assessment items of the traveling wave tube. Therefore, a new high-reliability energy transmission structure for high-power helical traveling wave tubes is required. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems of the power tolerance capacity and reliability of the coupling structure for high-power output of helical traveling wave tubes, achieve as small electromagnetic reflection as possible within the frequency band, ensure low-loss transmission, provide a reliable structure that can meet various test requirements, and make its transmission characteristics meet the usage requirements of high-power pulse traveling wave tubes.

[0005] The present invention provides an energy transmission structure for a traveling wave tube with reasonable structural design, high power, and high reliability, which is a measure applicable to the energy transmission structure design of high-average-power helical traveling wave tubes, and is specifically achieved by the following specific technical means:

[0006] An energy transmission structure of a high-power helical pulse traveling wave tube, including an energy transmission structure, wherein the energy transmission structure is composed of a waveguide structure, an impedance transformer, a connecting piece, a tapered coaxial window structure, and an outer conductor;

[0007] The impedance transformer is installed inside the waveguide structure, and one end of the impedance transformer is provided with a mounting hole. The connecting piece is installed in the mounting hole. The outer conductor is connected to one side of the waveguide structure, and one end of the connecting piece is arranged inside the outer conductor. The tapered coaxial window structure is sleeved outside the connecting piece, and the tapered coaxial window structure is sealed and connected inside the outer conductor.

[0008] Further, the impedance transformer is a three-stage Chebyshev impedance transformer.

[0009] Further, a waveguide connection transition region is provided at the connection of the outer conductor close to the waveguide structure, and the ratio of the inner diameters of the waveguide connection transition regions is 1.2∶1.

[0010] Further, a conductor gradual change region is provided in the middle section of the connecting member, and the ratio of the diameters of the large end to the small end of the conductor gradual change region is 1.39∶1.

[0011] Further, the connecting member is divided into two parts, a sleeve and an inner conductor, and the mating surfaces inside and outside thereof are conical.

[0012] Further, the sleeve is welded to the impedance converter as a whole by copper-silver soldering in a hydrogen furnace.

[0013] Further, the mating taper angle of the sleeve and the inner conductor is 4°±5′, the small end diameter of the sleeve is 6.1 mm, and the large end diameter of the inner conductor is 8.3 mm.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. By adopting a waveguide with a coaxial-to-three-stage Chebyshev impedance converter, the power capacity tolerance of the energy transmission structure of the helix traveling wave tube is increased;

[0016] 2. By adopting three-dimensional simulation technology, the design is further optimized to obtain a smaller standing wave ratio, significantly reducing the loss of microwave power by the transmission line and reducing the influence of high-frequency reflection on the traveling wave tube;

[0017] 3. The connection structure between the coaxial and the waveguide adopts a taper fit design, and the application method of the process structure is novel, with high connection reliability. It is not only convenient for assembly, can ensure that the repeated assembly accuracy remains unchanged, but also is easy to ensure the coaxiality requirement after the parts are assembled, well eliminating the fit clearance, having good self-locking and sealing properties, improving its transmission performance, and ensuring the reliability of the energy transmission structure of the high-average-power traveling wave tube. Description of the Drawings

[0018] Figure 1 is a schematic diagram of the energy transmission structure of the present invention.

[0019] Figure 2 is a curve graph of the analysis result of the three-dimensional simulation technology of the present invention.

[0020] Figure 3 is a schematic diagram of the structure after the reliability structure of the connection between the coaxial window and the waveguide of the present invention is optimized.

[0021] In the figure, the corresponding relationship between the component names and the drawing reference numerals is:

[0022] 1. Waveguide structure; 2. Impedance transformer; 3. Connector; 301. Inner conductor; 302. Sleeve; 4. Conical coaxial window structure; 5. Outer conductor. Specific embodiments

[0023] The following further describes the embodiments of the present invention in detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0024] In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0025] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] Embodiment 1

[0027] As shown in the attached Figure 1 figure:

[0028] The present invention provides an energy transmission structure for a high-power helix traveling-wave tube, including an energy transmission structure, which is composed of a waveguide structure 1, an impedance transformer 2, a connector 3, a conical coaxial window structure 4, and an outer conductor 5; the impedance transformer 2 is installed inside the waveguide structure 1, and one end of the impedance transformer 2 is provided with a mounting hole, the connector 3 is installed in the mounting hole, the outer conductor 5 is connected to one side of the waveguide structure 1, and one end of the connector 3 is arranged inside the outer conductor 5, the conical coaxial window structure 4 is sleeved outside the connector 3, and the conical coaxial window structure 4 is sealed and connected inside the outer conductor 5;

[0029] Among them, the impedance transformer 2 is a three-stage Chebyshev impedance transformer.

[0030] The outer conductor 5 is provided with a waveguide connection transition zone near the connection with the waveguide structure 1 , and the ratio of the inner diameters a:b of the waveguide connection transition zone is 1.2:1.

[0031] The middle section of the connector 3 is provided with a conductor gradient zone, and the ratio of the diameters of the large and small ends of the conductor gradient zone is c:d is 1.39:1.

[0032] Select the coaxial line and impedance transformer of the best size, and optimize the impedance matching of the transmission line through 3D electromagnetic simulation software. The 3D electromagnetic simulation calculation and analysis results are as follows: Figure 2 As shown, the standing wave ratio within the frequency band is about 1.25, and the actual tube installation test is about 1.35, with a high degree of consistency.

[0033] Example 2

[0034] like Figure 3 As shown, the connector 3 is divided into two parts, a sleeve 301 and an inner conductor 302, and the inner and outer mating surfaces of the two are conical. By utilizing the tapered feature of the mating surface, the inner conductor 302 is tightened with a nut, so that the fit of the two parts becomes tighter and tighter, and the fit gap is completely eliminated.

[0035] The sleeve 301 is fixed on the impedance transformer 2 by a mold, and is welded to the impedance transformer 2 by copper-silver welding in a hydrogen furnace. The inner conductor 302 is then inserted into the sleeve 301 along a taper for assembly. The degree of fit can be determined based on the height position of the inner conductor 302 in the sleeve 301.

[0036] The matching cone angle of the sleeve 301 and the inner conductor 302 is 4°±5′, the small end diameter of the sleeve 301 is 6.1 mm, and the large end diameter of the inner conductor 302 is 8.3 mm.

[0037] In summary, the present invention performs structural design based on engineering calculations and three-dimensional simulation software, and has achieved the following technical advances:

[0038] 1. By adopting the energy transmission structure of coaxial window output to waveguide, the power capacity of the energy transmission structure is improved; through the optimization design of three-dimensional simulation software, a lower voltage standing wave ratio is achieved, the negative impact of high-frequency reflection on the traveling wave tube is reduced, and the energy transmission demand of the helical traveling wave tube at a 10% working ratio is met.

[0039] 2. By adopting a cone-matched energy transmission structure and a reliable connection method, the high-reliability transmission characteristics of a high-power helical traveling wave tube under a large working ratio condition are achieved.

[0040] 3. By designing an energy transmission device with a reasonable structure, high power, and high reliability, the reliability assessment indicators in the development project of the S-band high-power helix traveling wave tube are met. Currently, this traveling wave tube has passed various harsh environmental tests in the appraisal process (-40°C low-temperature operation, 55°C high-temperature operation, -55°C low-temperature storage test, 70°C high-temperature storage test; non-operating state: a = 20g, τ = 11ms, 18 impacts in total in six directions of ±X, ±Y, ±Z axes for the shock and vibration test, temperature cycle test, low-pressure test, mildew test, salt spray test, etc.). During the appraisal, the 800-hour (10% of the guaranteed service life) life test was also successfully completed. During the test, the performance of the traveling wave tube was normal and the operation was stable, indicating that this energy transmission structure has achieved the design goal of long life and high reliability.

[0041] The present invention is applicable to the helix traveling wave tube in the S-band frequency range, realizing a 10% duty cycle, a 12-kW pulsed output power, and a guaranteed service life of 8,000 hours. The indicators of long life and high output power (greater than 1.2 kW) in the project put forward higher requirements for the output coupling structure. The service life and average output power of similar helix traveling wave tubes in the same band are mostly within 3,000 hours and 350 W. The small power capacity determines that most of them adopt a coaxial output structure. The energy transmission structure of the present invention has been greatly improved in terms of both power capacity and service reliability compared with the previous similar products.

[0042] The embodiments of the present invention are given for purposes of illustration and description, and are not exhaustive or limit the present invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are chosen and described in order to better explain the principles of the present invention and its practical applications, and to enable those of ordinary skill in the art to understand the present invention and design various embodiments with various modifications suitable for specific purposes.

Claims

1. The energy transmission structure of a high-power helical pulse traveling wave tube, including an energy transmission structure, is characterized in that: The energy transmission structure is composed of a waveguide structure (1), an impedance transformer (2), a connecting piece (3), a conical coaxial window structure (4) and an outer conductor (5); The impedance transformer (2) is a three-stage Chebyshev impedance transformer; The impedance transformer (2) is installed inside the waveguide structure (1), and one end of the impedance transformer (2) is provided with a mounting hole. The connecting piece (3) is installed in the mounting hole. The outer conductor (5) is connected to one side of the waveguide structure (1), and one end of the connecting piece (3) is arranged inside the outer conductor (5). The conical coaxial window structure (4) is sleeved outside the connecting piece (3), and the conical coaxial window structure (4) is sealed and connected inside the outer conductor (5); The connecting piece (3) is divided into two parts, a sleeve (301) and an inner conductor (302), and the mating surfaces inside and outside of the two are conical; The energy transmission structure is designed and optimized by using three-dimensional simulation technology.

2. The energy transmission structure of the high-power helix traveling wave tube according to claim 1, wherein: The outer conductor (5) is provided with a waveguide connection transition area near the connection with the waveguide structure (1), and the inner diameter ratio of the waveguide connection transition area is 1.2∶1.

3. The energy transmission structure of the high-power helix traveling wave tube as described in claim 1 is characterized in that: The middle section of the connecting piece (3) is provided with a conductor gradual change area, and the diameter ratio of the large end to the small end of the conductor gradual change area is 1.39∶1.

4. The energy transmission structure of the high-power helical pulse traveling wave tube according to claim 1, characterized in that: The sleeve (301) is welded to the impedance transformer (2) as a whole by copper-silver welding in a hydrogen furnace.

5. The energy transmission structure of the high-power helical pulse traveling wave tube according to claim 1, characterized in that: The mating cone angle of the sleeve (301) and the inner conductor (302) is 4°±5′, the small head diameter of the sleeve (301) is 6.1 mm, and the large head diameter of the inner conductor (302) is 8.3 mm.

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