阅读说明：本技术 一种谐振腔及其阻抗失配的调节方法 (Resonant cavity and impedance mismatch adjusting method thereof ) 是由 耿志辉 顾红红 张瑞 沈斌 杨修东 廖云峰 于 2021-07-19 设计创作，主要内容包括：本公开提供一种谐振腔阻抗失配的调节方法,包括：设置谐振腔中的内导体横截面为第一椭圆形；设置谐振腔中的外导体横截面为第二椭圆形；在所述谐振腔的波导耦合孔旁设置调节销钉；以及将谐振腔中的内导体与外导体偏心设置。同时本公开还提供一种速调管谐振腔,其由内至外包括内导体、内层电子注通道、外层电子注通道、以及外导体；其中,所述内导体的横截面为第一椭圆形；所述外导体的横截面为第二椭圆形；所述内导体与外导体偏心设置；所述谐振腔的波导耦合孔旁设置有调节销钉。(The present disclosure provides a method for adjusting impedance mismatch of a resonant cavity, including: setting the cross section of an inner conductor in the resonant cavity to be a first ellipse; setting the cross section of an outer conductor in the resonant cavity to be a second ellipse; arranging an adjusting pin beside a waveguide coupling hole of the resonant cavity; and eccentrically arranging the inner conductor and the outer conductor in the resonant cavity. The disclosure also provides a klystron resonant cavity which comprises an inner conductor, an inner electron beam channel, an outer electron beam channel and an outer conductor from inside to outside; wherein the cross section of the inner conductor is a first ellipse; the cross section of the outer conductor is a second ellipse; the inner conductor and the outer conductor are eccentrically arranged; and an adjusting pin is arranged beside the waveguide coupling hole of the resonant cavity.)

1. A method of tuning a resonant cavity impedance mismatch, comprising:

setting the cross section of an inner conductor in the resonant cavity to be a first ellipse;

setting the cross section of an outer conductor in the resonant cavity to be a second ellipse;

arranging an adjusting pin beside a waveguide coupling hole of the resonant cavity; and

the inner conductor and the outer conductor in the resonant cavity are eccentrically arranged.

2. The method according to claim 1, wherein the distribution of the electric field intensity of the inner electron beam channel and the outer electron beam channel is improved by adjusting the ratio of the major axis to the minor axis of the first ellipse.

3. The method according to claim 1, wherein the electric field intensity distribution of the inner electron beam channel and the outer electron beam channel is improved by adjusting the ratio of the major axis to the minor axis of the second ellipse.

4. The method for adjusting impedance mismatch of a resonant cavity according to claim 1, wherein the radius of the adjusting pin is adjustable.

5. The method for adjusting impedance mismatch of resonant cavity according to claim 4, wherein the distance between the adjusting pin and the center position of the outer conductor is adjustable.

6. The method for adjusting impedance mismatch of a resonant cavity according to claim 5, wherein the distribution of electric field intensity on the electron beam channel near the waveguide coupling hole is improved by setting the radius of the adjusting pin and/or adjusting the distance between the adjusting pin and the center position of the outer conductor.

7. The method according to claim 1, wherein the distribution of electric field strength in the inner electron beam channel and the outer electron beam channel of the resonant cavity is improved by adjusting an eccentric distance between the inner conductor and the outer conductor.

8. A klystron resonant cavity comprises an inner conductor, an inner electron beam channel, an outer electron beam channel and an outer conductor from inside to outside; wherein the content of the first and second substances,

the cross section of the inner conductor is a first ellipse;

the cross section of the outer conductor is a second ellipse;

the inner conductor and the outer conductor are eccentrically arranged;

and an adjusting pin is arranged beside the waveguide coupling hole of the resonant cavity.

9. The klystron resonator cavity of claim 8, an eccentric distance between a center of the first ellipse and a center of the second ellipse being adjustable.

10. The klystron resonator of claim 8, the tuning pin disposed at a corresponding output waveguide coupling hole.

Technical Field

The disclosure relates to the technical field of vacuum electronics, in particular to a klystron coaxial resonant cavity and an impedance mismatch adjusting method thereof.

Background

The klystron is a microwave vacuum device which converts electron beam energy into microwave energy based on a speed modulation principle; its high-frequency interaction system is a separated resonant cavity, so that it possesses the advantages of high power, high gain, high efficiency and high stability, etc. The resonant cavity is used as a high-frequency interaction circuit of the klystron, and the characteristics of the resonant cavity have decisive influence on performance indexes such as power, efficiency, gain, bandwidth and the like of the klystron. For the output resonant cavity, the gap capacitance of the resonant cavity is increased along with the increase of the diameter of the drift tube head, and under the condition of keeping a constant value of the loading quality factor, the nonuniformity of an electric field on an inner-layer electron beam channel and an outer-layer electron beam channel is increased due to the coupling hole of the cavity and the output waveguide.

For the high-power multi-beam klystron, the adoption of a coaxial resonant cavity can improve the nonuniformity of an electric field on an inner-layer electron beam channel and an outer-layer electron beam channel; however, for klystrons with high number of electron beams, such as 30 beams, 37 beams, 40 beams, and the like, the electric field nonuniformity on the electron beam channels on the inner layer and the outer layer of the resonant cavity is still very serious.

Disclosure of Invention

Technical problem to be solved

Based on the above problems, the present disclosure provides a resonant cavity and an impedance mismatch adjusting method thereof, so as to alleviate the technical problems of the prior art, such as severe non-uniformity of electric fields in the inner and outer electron beam channels of the coaxial resonant cavity.

(II) technical scheme

In one aspect of the present disclosure, a method for adjusting impedance mismatch of a resonant cavity is provided, including: setting the cross section of an inner conductor in the resonant cavity to be a first ellipse; setting the cross section of an outer conductor in the resonant cavity to be a second ellipse; arranging an adjusting pin beside a waveguide coupling hole of the resonant cavity; and eccentrically arranging the inner conductor and the outer conductor in the resonant cavity.

According to the embodiment of the disclosure, the distribution of the electric field intensity of the inner electron beam channel and the outer electron beam channel is improved by adjusting the ratio of the long axis to the short axis of the first ellipse.

According to the embodiment of the disclosure, the distribution of the electric field intensity of the inner electron beam channel and the outer electron beam channel is improved by adjusting the ratio of the long axis to the short axis of the second ellipse.

According to the embodiment of the disclosure, the radius of the adjusting pin is adjustable.

According to the embodiment of the disclosure, the distance between the adjusting pin and the center position of the outer conductor is adjustable.

According to the embodiment of the disclosure, the distribution of the electric field intensity on the electron beam channel near the waveguide coupling hole is improved by setting the radius of the adjusting pin and/or adjusting the distance between the adjusting pin and the central position of the outer conductor.

According to the embodiment of the disclosure, the distribution of electric field strength on the inner electron beam channel and the outer electron beam channel of the resonant cavity is improved by adjusting the eccentric distance between the inner conductor and the outer conductor.

In another aspect of the present disclosure, a klystron resonator is provided, which comprises, from inside to outside, an inner conductor, an inner electron beam channel, an outer electron beam channel, and an outer conductor; wherein the cross section of the inner conductor is a first ellipse; the cross section of the outer conductor is a second ellipse; the inner conductor and the outer conductor are eccentrically arranged; and an adjusting pin is arranged beside the waveguide coupling hole of the resonant cavity.

According to an embodiment of the present disclosure, the eccentric distance between the center of the first ellipse and the center of the second ellipse is adjustable.

According to the embodiment of the disclosure, the adjusting pin is arranged at the position corresponding to the output waveguide coupling hole.

(III) advantageous effects

According to the technical scheme, the resonant cavity and the impedance mismatch adjusting method thereof disclosed by the invention have at least one or part of the following beneficial effects:

(1) the impedance of the resonant cavity can be effectively adjusted, and the difference of the impedance at different electron beam positions is reduced;

(2) the distribution of the electric field intensity of the inner and outer electron beams can be improved;

(3) the distribution of the electric field strength on the electron beam channel near the coupling aperture can be improved.

Drawings

Fig. 1 is a schematic structural diagram of a single-beam cylindrical reentrant resonant cavity in the prior art.

Fig. 2 is a schematic structural diagram of a multi-beam cylindrical reentrant resonant cavity in the prior art.

Fig. 3 is a schematic structural diagram of a conventional coaxial multi-beam cylindrical reentrant output cavity in the prior art.

Fig. 4 is a variation curve of normalized electric field intensity along the circumference of inner and outer electron beams of a conventional coaxial multi-beam cylindrical reentrant output resonant cavity.

Fig. 5 is a schematic structural diagram of an elliptical eccentric structure coaxial multi-beam output cavity according to an embodiment of the present disclosure.

Fig. 6 is a schematic structural view at the center of a resonant cavity of an embodiment of the present disclosure.

FIG. 7 is a comparison of electron beams in the inner and outer layers.

Fig. 8 is a flowchart of a method for adjusting a resonant cavity impedance mismatch according to an embodiment of the present disclosure.

Detailed Description

The invention provides a resonant cavity and an impedance mismatch adjusting method thereof, which can effectively adjust the impedance of the coaxial resonant cavity, reduce the impedance difference at different electron beam positions and improve the distribution uniformity of the electric field intensity on an electron beam channel.

For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

In carrying out the present disclosure, the inventors have found that in existing klystrons, in order to effectively interact the high frequency electric field in the cavity with the axially moving electron beam, a dual-entry cavity with drift tubes is typically employed, with the high frequency electric field concentrated in the cavity gap region. FIG. 1 is a diagram of a commonly used operating system operating at TM₀₁₀A cylindrical reentrant cavity of a mode and a cross-sectional view. Other cross-sectional shapes of the resonator may be used depending on the particular requirements of the klystron design. It should be appreciated that the characteristic impedance R/Q and the on-load quality factor Q_LIs an outputTwo important parameters of the resonator. The characteristic impedance represents the magnitude of the electric field created by the stored energy of the resonator over the gap of the resonator during a high frequency period. The larger the characteristic impedance, the stronger the electron beam interaction with the resonant cavity high frequency electric field, as follows:

R/Q＝[∫Edz]²/(2ω₀W)；

w is the energy stored in resonant cavity, omega₀Is the operating angular frequency;

Q_L＝ω₀W/P；

in the above formula, P represents the total power loss, including the average power loss of the cavity itself and the power loss of an external circuit load coupled to the resonant cavity within one cycle; for the case of coupling of the output cavity to the waveguide, there is a load quality factor Q_LThe size of (c) depends on the size of the coupling port.

For the operating voltage V₀And an operating current I₀Klystron of (1), its direct-current impedance Z₀＝V₀/I₀In order to obtain optimum efficiency of electron interaction with the output cavity, R/Q.Q.is usually required_L＝ (1.2～1.5)Z₀. In the practical applications of the klystrons, some klystrons work at low voltage, and the working current of the klystrons needs to be increased on the premise of ensuring certain output power; the klystron working at a large current means the increase of the cathode load of an electron gun, and a plurality of electron gun cathodes are needed to be adopted in order to reduce the cathode load of the electron gun and ensure the service life of the cathode; the klystron adopting a plurality of electron gun cathodes is called a multi-beam klystron; the multi-beam klystron adopts a resonant cavity which is a multi-beam resonant cavity.

In the base-mode multi-beam klystron, the number of electron beams generally used is 7, 8, 9, 12, 15, 17, 30, 37, 40, etc. For a high-power multi-beam klystron, the number of electron beams is large; in the multi-beam resonant cavity, N electron beam drift tubes are concentrated in the middle of the resonant cavity to form a drift tube head, and compared with a single-beam klystron resonant cavity (shown in figure 1), the diameter of the drift tube head can be compared with the diameter of the resonant cavity, as shown in figure 2. Fig. 3 is a coaxial multi-beam cylindrical reentrant output cavity. To achieve a specific load quality factor, the coupling hole width is W, the inner conductor radius is R1, and the cavity radius is R2. Fig. 4 shows the variation of the normalized electric field strength along the circumference of the inner electron beam (radius Ri) and the outer electron beam (radius Ro), and it can be seen from fig. 4 that the normalized maximum field strength is about 3 times the minimum field strength at the positions of the inner and outer electron beams.

Therefore, in the embodiment of the present disclosure, a method for adjusting impedance mismatch of a resonant cavity is provided, which has solved the technical problem of serious non-uniformity of an electric field on electron beam channels on inner and outer layers of the resonant cavity, and is shown in fig. 5 to 8, where the method for adjusting impedance mismatch of a resonant cavity includes:

operation S1: setting the cross section of an inner conductor in the resonant cavity to be a first ellipse;

according to the embodiments of the present disclosure, compared to the conventional coaxial multi-beam output resonator as shown in fig. 3, the resonator in the present disclosure has the inner conductor configured in the first elliptical shape (as shown in fig. 5, the major axis of the first elliptical shape is a, and the minor axis of the first elliptical shape is b), and by adjusting the ratio of the major axis and the minor axis of the inner conductor, the distribution of the electric field intensity of the inner-layer electron beam channel and the outer-layer electron beam channel can be improved.

Operation S2: setting the cross section of an outer conductor in the resonant cavity to be a second ellipse;

according to the embodiments of the present disclosure, compared to the conventional resonant cavity as shown in fig. 3, the outer conductor of the resonant cavity in the present disclosure is configured in the second elliptical shape (as shown in fig. 5, the major axis of the second elliptical shape is a, and the minor axis of the second elliptical shape is B), and by adjusting the ratio of the major axis and the minor axis of the outer conductor, the distribution of the electric field intensity of the electron beam passage in the inner layer and the electron beam passage in the outer layer can also be improved.

Operation S3: arranging an adjusting pin beside a waveguide coupling hole of the resonant cavity;

according to the embodiment of the disclosure, compared with the conventional resonant cavity shown in fig. 3, the resonant cavity in the disclosure is provided with the adjusting pin beside the waveguide coupling hole of the resonant cavity, as shown in fig. 5, the radius of the adjusting pin is r, the distance h between the adjusting pin and the central position O is adjustable, and the distribution of the electric field intensity on the electron beam channel near the coupling hole can be improved by adjusting the radius r and the distance h of the adjusting pin.

Operation S4: the inner conductor and the outer conductor in the resonant cavity are eccentrically arranged;

according to the embodiment of the present disclosure, compared to the conventional resonant cavity as shown in fig. 3, the inner conductor and the outer conductor of the resonant cavity in the present disclosure adopt an eccentric arrangement structure, as shown in fig. 6, the eccentric distance between the center O' of the inner conductor and the center O of the outer conductor is d, and by adjusting the eccentric distance d between the inner conductor and the outer conductor, the distribution of the electric field intensity on the electron beam channel in the inner layer and the outer layer of the entire resonant cavity can be further improved.

The present disclosure also provides a resonant cavity of a klystron, as shown in fig. 5-6, the resonant cavity includes, from inside to outside, an inner conductor, an inner electron beam channel, an outer electron beam channel, and an outer conductor; the cross section of the inner conductor is a first ellipse, the center of the inner conductor is O' as shown in fig. 6, and the proportion of the long axis and the short axis of the first ellipse can be adjusted according to actual requirements, so that the optimal distribution uniformity of the electric field intensity on the electron beam channel is achieved; the cross section of the outer conductor is a second ellipse, the center of the outer conductor is O as shown in FIG. 6, and the proportion of the long axis and the short axis of the second ellipse can be adjusted according to actual requirements, so that the optimal distribution uniformity of the electric field intensity on the electron beam channel is achieved; the inner conductor and the outer conductor are eccentrically arranged, as shown in fig. 6, the eccentric distance between the center O' of the inner conductor and the center O of the outer conductor is d, and the eccentric distance can be adjusted or selected according to actual needs.

According to the embodiment of the disclosure, an adjusting pin is arranged beside the waveguide coupling hole of the resonant cavity, and the radius of the adjusting pin can be adjusted or selected according to actual needs.

According to the embodiment of the present disclosure, if the adjusting pin is disposed at the coupling hole corresponding to the output waveguide, as shown in fig. 5, the distance between the adjusting pin and the center of the outer conductor is adjusted or selected according to actual needs, so as to achieve the optimal distribution uniformity of the electric field intensity on the electron beam channel.

So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It is to be noted that, in the attached drawings or in the description, the implementation modes not shown or described are all the modes known by the ordinary skilled person in the field of technology, and are not described in detail. Further, the above definitions of the various elements and methods are not limited to the various specific structures, shapes or arrangements of parts mentioned in the examples, which may be easily modified or substituted by those of ordinary skill in the art.

From the above description, those skilled in the art should clearly recognize the resonant cavity and the adjustment method of the impedance mismatch thereof according to the present disclosure.

In summary, the present disclosure provides a resonant cavity and an impedance mismatch adjustment method thereof, which can effectively adjust the impedance of the resonant cavity through the ovalization of the inner and outer conductors and the eccentricity between the inner and outer conductors, so as to reduce the impedance difference at different electron beam positions.

It should also be noted that directional terms, such as "upper", "lower", "front", "rear", "left", "right", and the like, used in the embodiments are only directions referring to the drawings, and are not intended to limit the scope of the present disclosure. Throughout the drawings, like elements are represented by like or similar reference numerals. Conventional structures or constructions will be omitted when they may obscure the understanding of the present disclosure.

And the shapes and sizes of the respective components in the drawings do not reflect actual sizes and proportions, but merely illustrate the contents of the embodiments of the present disclosure. Furthermore, in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify a corresponding element does not by itself connote any ordinal number of the element or any ordering of one element from another or the order of manufacture, and the use of the ordinal numbers is only used to distinguish one element having a certain name from another element having a same name.

In addition, unless steps are specifically described or must occur in sequence, the order of the steps is not limited to that listed above and may be changed or rearranged as desired by the desired design. The embodiments described above may be mixed and matched with each other or with other embodiments based on design and reliability considerations, i.e., technical features in different embodiments may be freely combined to form further embodiments.

Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and furthermore they may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Also in the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware.

The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present disclosure in further detail, and it should be understood that the above-mentioned embodiments are only illustrative of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.