A structure and method for suppressing oscillation of a klystron output circuit and a klystron

Abstract

The present invention discloses a structure for suppressing oscillation of a klystron output circuit, which is characterized by comprising: a coupling cavity; a pre-cavity connected to the coupling cavity; a mode isolation ring arranged on the inner wall of the pre-cavity, wherein the axis of the mode isolation ring coincides with the axis of the pre-cavity. By adding a mode isolation ring in the pre-cavity, the high-order mode oscillation is removed from the working bandwidth range by utilizing the characteristics that the mode isolation ring has a small influence on the working mode frequency and a large influence on the oscillation frequency of the high-order mode, and the noise spectrum level can be reduced without changing the spacing and shape of the gap between the two resonant cavities, thereby eliminating the influence of the high-order mode oscillation.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave electric vacuum devices, and in particular to a structure and method for suppressing oscillation of a klystron output circuit, and a klystron. Background Art

[0002] As a microwave power amplifier, the klystron has the advantages of high power, high gain, high efficiency and long life, and is widely used in the field of radar technology. In order to widen the bandwidth of the klystron, the output circuit usually adopts an overlapping mode double-gap coupled cavity. Because there is internal feedback between the two resonant cavities in the double-gap coupled cavity output circuit, it will cause non-working mode oscillation under certain conditions, causing the output circuit to spark, and seriously damaging the output window, causing the klystron to leak, so that the klystron cannot work normally. Therefore, suppressing the non-working mode oscillation of the klystron and reducing the level of the noise spectrum are of great significance to improving the reliability of the klystron and ensuring its normal operation.

[0003] For example, in the prior art, the S-band klystron adopts an overlapping mode double-gap coupled cavity structure, with an output peak power of more than 1MW and a bandwidth of 11% (Wang Yong, Yao-Gen Ding, Pu-Kun Liu, et.al. Development of an S-Band Klystron With Bandwidth of More Than 11%, IEEE Transactions on Plasma Science, 2006, 34(3): 572-575.). However, during the use of the klystron, due to the existence of high-order mode oscillations at individual frequency points, the level of the clutter spectrum is high, which causes the output circuit to spark, affecting the normal operation of the klystron. Summary of the invention

[0004] In order to solve the above technical problems, the present invention discloses a structure and method for suppressing oscillation of a klystron output circuit and a klystron, which can effectively eliminate oscillations in non-working modes, reduce the level of noise spectrum, and improve the reliability of the klystron.

[0005] A structure for suppressing oscillation of a klystron output circuit, comprising:

[0006] Coupler cavity;

[0007] A front cavity connected to the coupling cavity;

[0008] A mold isolation ring is arranged on the inner wall of the front cavity, the axis of the mold isolation ring coincides with the axis of the front cavity, and the mold isolation ring is used to reduce the level of the noise spectrum.

[0009] According to some embodiments of the present invention, the mold isolation ring includes an inner ring and an outer ring, the outer ring is sleeved on the outside of the inner ring, the centers of the inner ring and the outer ring coincide, and the outer side of the outer ring is connected to the inner wall of the front cavity.

[0010] According to some embodiments of the present invention, the inner ring has an inner diameter of 56-58 mm, and the outer ring has an outer diameter of 61-63 mm.

[0011] According to some embodiments of the present invention, the thickness of the inner ring is 2-4 mm, and the thickness of the outer ring is 1-2 mm.

[0012] According to some embodiments of the present invention, the width of the inner ring is 1 to 3 mm, and the width of the outer ring is 1 to 3 mm.

[0013] According to some embodiments of the present invention, the mold spacer ring is obtained by melting or rolling oxygen-free copper.

[0014] According to some embodiments of the present invention, the mold isolation ring is welded to the inner wall of the front cavity by brazing.

[0015] According to some embodiments of the present invention, the brazing temperature is 910°C.

[0016] The invention also discloses a klystron tube, comprising the above-mentioned structure for suppressing the oscillation of the klystron tube output circuit.

[0017] The invention also discloses a method for suppressing the oscillation of the klystron output circuit, which comprises welding the mold isolation ring in the structure for suppressing the oscillation of the klystron output circuit at the middle position of the front cavity.

[0018] Through the above technical scheme, the present invention adds a mode isolation ring in the front cavity, utilizing the characteristics that the mode isolation ring has little effect on the working mode frequency and a greater impact on the oscillation frequency of the higher-order mode, thereby removing the high-order mode oscillation from the working bandwidth range and reducing the noise spectrum level. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram schematically shows a structure for suppressing oscillation of a klystron output circuit according to an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of the structure of a pre-cavity of a structure for suppressing oscillation of a klystron output circuit according to an embodiment of the present invention is shown;

[0021] Figure 3 A schematic diagram of the structure of a mode isolation ring of a structure for suppressing oscillation of a klystron output circuit according to an embodiment of the present invention is shown;

[0022] Figure 4A schematic structural diagram schematically showing another perspective of a mode isolation ring of a structure for suppressing oscillation of a klystron output circuit according to an embodiment of the present invention;

[0023] In the above drawings, the meanings of the reference numerals are as follows:

[0024] 1-front cavity;

[0025] 2-coupled cavity;

[0026] 3- coupling slot;

[0027] 4-mold spacer ring;

[0028] 41-Inner ring;

[0029] 42-Outer ring. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0031] But it should be understood that these descriptions are exemplary only, and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, the description of known techniques is omitted to avoid unnecessary confusion of concepts of the present invention.

[0032] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The term "comprising" used herein indicates the existence of features, steps, operations, but does not exclude the existence or addition of one or more other features.

[0033] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0034] Based on the need for anti-interference, the klystron needs to have a certain instantaneous bandwidth. The increase in the bandwidth of the klystron is likely to produce high-order mode oscillations, which will affect the efficiency and primary gain of the klystron, thereby causing the klystron efficiency to decrease or malfunction.

[0035] In order to solve the above technical problems, the present invention discloses a structure for suppressing the oscillation of the klystron output circuit, which can effectively eliminate the oscillation of non-working modes, reduce the level of the noise spectrum, and improve the reliability of the klystron.

[0036] Klystrons include dual-cavity klystrons, which include two resonant cavities, namely the input cavity and the output cavity. The input microwave signal is sent into the input cavity through an energy coupler, and a microwave signal voltage is formed outside the resonant cavity gap. Here, the electron beam is modulated by the velocity of the microwave field and then enters the field-free drift tube. During the drift process, electrons cluster and form density modulation in the electron beam. The density-modulated electron beam exchanges energy with the microwave field of the output cavity gap, and the electrons give energy to the microwave field to complete the function of amplification or oscillation.

[0037] Figure 1 The schematic diagram schematically shows a structure for suppressing oscillation of a klystron output circuit according to an embodiment of the present invention.

[0038] A structure for suppressing oscillation of a klystron output circuit, taking an S-band broadband klystron as an example, Figure 1 As shown, the structure includes a front cavity 1, a coupling cavity 2 and a mold isolation ring 4, wherein a coupling groove 3 is formed at the connection between the front cavity 1 and the coupling cavity 2.

[0039] According to some embodiments of the present invention, the front cavity 1 is coupled to the coupling cavity 2 .

[0040] Figure 2 The schematic diagram of the structure of the pre-cavity of the structure for suppressing the oscillation of the klystron output circuit according to the embodiment of the present invention is schematically shown.

[0041] According to some embodiments of the present invention, Figure 2 As shown, optionally, the front cavity 1 is a cylindrical structure, the isolation ring 4 is arranged on the inner wall of the front cavity 1, the axis of the isolation ring 4 coincides with the axis of the front cavity 1, and the isolation ring 4 is used to reduce the level of the noise spectrum.

[0042] According to some embodiments of the present invention, the mold spacer ring 4 is in a circular ring shape.

[0043] According to some embodiments of the present invention, the mold spacer ring 4 is perpendicular to the inner wall of the front cavity 1 .

[0044] According to some embodiments of the present invention, the mold isolation ring 4 is welded to the inner wall of the front cavity 1 by brazing.

[0045] According to some embodiments of the present invention, the brazing temperature is 910°C.

[0046] Figure 3 The schematic diagram of the structure of the mode isolation ring of the structure for suppressing the oscillation of the klystron output circuit according to the embodiment of the present invention is schematically shown.

[0047] According to some embodiments of the present invention, Figure 3As shown, the mold isolation ring 4 includes an inner ring 41 and an outer ring 42. The outer ring 42 is sleeved on the outer side of the inner ring 41. The centers of the inner ring 41 and the outer ring 42 coincide with each other. The outer side of the outer ring 42 is connected to the inner wall of the front cavity 1.

[0048] According to some embodiments of the present invention, the inner ring 41 and the outer ring 42 are concentric rings.

[0049] According to some embodiments of the present invention, the outer ring 42 is disposed at a midline of an outer side surface of the inner ring 41 .

[0050] According to some embodiments of the present invention, the cross-section of the mold spacer ring 4 is T-shaped.

[0051] According to some embodiments of the present invention, the size of the spacer ring 4 is changed according to the size of the klystron, mainly by adjusting the outer diameters of the inner ring 41 and the outer ring 42 of the spacer ring 4 to adapt to klystrons of different specifications.

[0052] Figure 4 A schematic structural diagram from another perspective of a mode isolation ring of a structure for suppressing oscillation of a klystron output circuit according to an embodiment of the present invention is schematically shown.

[0053] According to some embodiments of the present invention, Figure 4 As shown, the inner ring diameter D1 of the inner ring 41 is 56-58 mm, and the outer ring diameter D2 of the outer ring 42 is 61-63 mm.

[0054] According to some embodiments of the present invention, optionally, the inner ring diameter of the inner ring 41 is 57 mm, and the outer ring diameter of the outer ring 42 is 62 mm, that is, the overall width of the isolation ring 4 is 5 mm. The isolation ring 4 has a smaller effect on the working mode frequency, but a greater effect on the oscillation frequency of the higher-order mode, and has a better effect in reducing the level of the noise spectrum.

[0055] According to some embodiments of the present invention, the thickness H1 of the inner ring 41 is 2-4 mm, and the thickness H2 of the outer ring 42 is 1-2 mm.

[0056] According to some embodiments of the present invention, the thickness of the inner ring 41 is 3 mm, the thickness of the outer ring 42 is 1 mm, the mode isolation ring 4 has a smaller effect on the working mode frequency, but a greater effect on the oscillation frequency of the higher-order mode, and has a better effect in reducing the level of the noise spectrum.

[0057] According to some embodiments of the present invention, the width of the inner ring 41 is 1 to 2 mm, and the width of the outer ring 42 is 1 to 2 mm.

[0058] According to some embodiments of the present invention, the width W1 of the inner ring 41 is 1.5 mm, the width W2 of the outer ring 42 is 1.5 mm, the mode isolation ring 4 has a smaller effect on the working mode frequency, but a greater effect on the oscillation frequency of the higher-order mode, and has a better effect on reducing the level of the noise spectrum.

[0059] According to some embodiments of the present invention, the mold spacer ring 4 is obtained by melting or rolling oxygen-free copper.

[0060] The present invention also discloses a klystron, including the above-mentioned structure for suppressing the oscillation of the klystron output circuit, including a pre-cavity, a coupling cavity and a mode isolation ring, wherein a coupling groove is formed at the connection between the pre-cavity and the coupling cavity.

[0061] According to some embodiments of the present invention, the pre-cavity is connected to the coupling cavity.

[0062] According to some embodiments of the present invention, the pre-cavity is a cylindrical structure, the isolation ring is arranged on the inner wall of the pre-cavity, the axis of the isolation ring coincides with the axis of the pre-cavity, and the isolation ring is used to reduce the level of the noise spectrum.

[0063] According to some embodiments of the present invention, the mold separation ring is perpendicular to the inner wall of the front cavity.

[0064] According to some embodiments of the present invention, the mold isolation ring is welded to the inner wall of the front cavity by brazing.

[0065] According to some embodiments of the present invention, the brazing temperature is 910°C

[0066] According to some embodiments of the present invention, the mold isolation ring includes an inner ring and an outer ring, the outer ring is sleeved on the outside of the inner ring, the centers of the inner ring and the outer ring coincide, and the outer side of the outer ring is connected to the inner wall of the front cavity 1.

[0067] According to some embodiments of the present invention, the inner ring and the outer ring are concentric rings.

[0068] According to some embodiments of the present invention, the outer ring is arranged at a position of a midline of an outer side surface of the inner ring.

[0069] According to some embodiments of the present invention, the cross-section of the mold spacer ring is T-shaped.

[0070] According to some embodiments of the present invention, the size of the spacer ring is changed according to the size of the klystron, and the difference is mainly reflected in the different outer diameters of the inner ring and the outer ring of the spacer ring.

[0071] According to some embodiments of the present invention, optionally, the inner ring diameter of the inner ring is 56-58 mm, and the outer ring diameter of the outer ring is 61-63 mm.

[0072] According to some embodiments of the present invention, optionally, the inner ring diameter of the inner ring is 57 mm, and the outer ring diameter of the outer ring is 62 mm, that is, the overall width of the mode isolation ring is 5 mm. The mode isolation ring has less effect on the working mode frequency, but has a greater effect on the oscillation frequency of the higher-order mode, and has a better effect in reducing the noise spectrum level.

[0073] According to some embodiments of the present invention, the thickness of the inner ring is 2-4 mm, and the thickness of the outer ring is 1-2 mm.

[0074] According to some embodiments of the present invention, the thickness of the inner ring is 3 mm, the thickness of the outer ring is 1 mm, the mode isolation ring 4 has a smaller effect on the working mode frequency, but a greater effect on the oscillation frequency of the higher-order mode, and has a better effect on reducing the level of the noise spectrum.

[0075] According to some embodiments of the present invention, the width of the inner ring is 1 to 2 mm, and the width of the outer ring is 1 to 2 mm.

[0076] According to some embodiments of the present invention, the width of the inner ring is 1.5 mm, the width of the outer ring is 1.5 mm, the mode isolation ring 4 has a smaller effect on the working mode frequency, but a greater effect on the oscillation frequency of the higher-order mode, and has a better effect on reducing the level of the noise spectrum.

[0077] According to some embodiments of the present invention, the spacer ring is obtained by melting or rolling oxygen-free copper.

[0078] The invention also discloses a method for suppressing the oscillation of the klystron output circuit, which comprises welding the mold isolation ring in the structure for suppressing the oscillation of the klystron output circuit at the middle position of the front cavity.

[0079] According to some embodiments of the present invention, the isolating mold ring is fastened to the inner wall of the front cavity of the klystron by high temperature (greater than 950° C.) brazing.

[0080] According to some embodiments of the present invention, during the brazing process, it is ensured that the mold spacer ring is perpendicular to the inner wall of the front cavity.

[0081] According to some embodiments of the present invention, during the brazing process, the mold spacer ring is brazed at a middle position of the inner wall of the front cavity.

[0082] Through the above technical scheme, the present invention adds a mode isolation ring in the front cavity, utilizes the characteristics that the mode isolation ring has little effect on the working mode frequency and a greater impact on the oscillation frequency of the higher-order mode, and removes the high-order mode oscillation from the working bandwidth range. It can reduce the level of the noise spectrum and eliminate the influence of the higher-order mode oscillation without changing the spacing and shape of the gap between the two resonant cavities.

[0083] It can be seen from the above technical solution that the present application has the characteristics of simple structure, easy processing, simple assembly and welding; high temperature brazing is adopted, and the structure is firm. At the same time, the above technical solution can be extended and applied to the output cavity of klystrons of other bands.

[0084] So far, the embodiments of the present disclosure have been described in detail in conjunction with the accompanying drawings. It should be noted that the implementation methods not shown or described in the drawings or the body of the specification are all forms known to ordinary technicians in the relevant technical field and are not described in detail. In addition, the above definitions of each component are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and ordinary technicians in the field can simply change or replace them.

[0085] It should also be noted that, in the specific embodiments of the present disclosure, unless otherwise indicated, the numerical parameters in the present specification and the appended claims are approximate values ​​and can be changed according to the desired characteristics obtained through the content of the present disclosure. Specifically, all numbers used in the specification and claims to express the size, range conditions, etc. of the composition should be understood to be modified by the term "about" in all cases. In general, the meaning of the expression refers to the change of ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments by a specific number.

[0086] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present invention may be combined and / or combined in various ways, even if such combinations and / or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention may be combined and / or combined in various ways without departing from the spirit and teachings of the present invention. All of these combinations and / or combinations fall within the scope of the present invention.

[0087] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A structure for suppressing oscillation of a klystron output circuit, characterized in that: include: Coupler cavity; A front cavity connected to the coupling cavity; A mold isolation ring is arranged on the inner wall of the pre-cavity, the axis of the mold isolation ring coincides with the axis of the pre-cavity, and the mold isolation ring is used to reduce the level of noise spectrum, wherein the mold isolation ring includes an inner ring and an outer ring, the outer ring is sleeved on the outside of the inner ring, the centers of the inner ring and the outer ring coincide, the outer side of the outer ring is connected to the inner wall of the pre-cavity, the inner ring diameter of the inner ring is 56~58mm, the outer ring diameter of the outer ring is 61~63mm, the thickness of the inner ring is 2~4mm, the thickness of the outer ring is 1~2mm, the width of the inner ring is 1~3mm, and the width of the outer ring is 1~3mm.

2. The structure according to claim 1, characterized in that: The mold spacer ring is obtained by melting or rolling oxygen-free copper.

3. The structure according to claim 2, characterized in that: The mold isolation ring is welded to the inner wall of the front cavity by brazing.

4. The structure according to claim 3, characterized in that The brazing temperature is 910°C.

5. A klystron, characterized in that: The invention comprises a structure for suppressing oscillation of a klystron output circuit as claimed in any one of claims 1 to 4.

6. A method for suppressing oscillation of a klystron output circuit, characterized in that: include: A mode isolation ring in the structure for suppressing oscillation of a klystron output circuit as claimed in any one of claims 1 to 3 is welded at the middle position of the pre-cavity.

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