Ku wave band slow wave circuit structure

Abstract

The utility model discloses a Ku wave band slow wave circuit structure, which relates to the technical field of microwave electric vacuum devices and is formed by welding an input section, a first load combination, a middle section, a second load combination and an output section. The bandwidth of the slow wave circuit structure can meet the requirement on the premise of ensuring power output; according to the invention, with the adoption of a joss-type coupling cavity structure, parameters such as cavity height, slot angle size and drift tube gap are designed to ensure that the slow wave circuit has enough bandwidth; the reliability of the slow-wave circuit structure is ensured by adopting an oscillation suppression technology, and the slow-wave circuit structure can be suitable for a Ku-band broadband high-power traveling wave tube; and the requirement that the pulse output power in the 2GHz bandwidth is 60kW in the Ku wave band is met.

Description

TECHNICAL FIELD

[0001] The utility model relates to microwave electric vacuum device technical field especially relates to a Ku wave band slow wave circuit structure. BACKGROUND

[0002] The bandwidth index of the traveling wave tube is the main factor influencing the imaging precision of the space target imaging radar, and how to expand the bandwidth as far as possible under the premise of guaranteeing the output power, efficiency and gain index of the traveling wave tube is a main technical difficulty in developing the traveling wave tube.

[0003] The slow wave circuit structure is the place of energy exchange between the electron beam and the high frequency field, and its performance influences the distribution of the high frequency traveling wave field and the size of the traveling wave phase velocity, and determines the interaction effect between the electron beam emitted from the electron gun and the traveling wave field.

[0004] The present project needs to develop a Ku wave band 2GHz bandwidth pulse output power of 60kW coupled cavity traveling wave tube, therefore the slow wave circuit satisfying the project requirement needs to be designed. SUMMARY

[0005] The utility model solves the technical problem in the background art and provides a Ku wave band slow wave circuit structure; it realizes the requirement of 2GHz bandwidth pulse output power of 60kW in the Ku wave band.

[0006] The utility model adopts the following technical scheme to solve the above technical problem:

[0007] A Ku wave band slow wave circuit structure is welded by an input section, a first load combination, an intermediate section, a second load combination and an output section;

[0008] The input section and the intermediate section are welded by a cavity 1 and a cavity sheet 1, and small porcelain is loaded in each cavity;

[0009] The output section is welded by a cavity 1, a cavity 2, a cavity 3, a cavity sheet 1, a cavity sheet 2 and a cavity sheet 3, and small porcelain is loaded in each cavity;

[0010] The first load combination and the second load combination are both composed of two cut-off cavities, one cut-off cavity sheet, two coupling large cavity sheets and three load porcelain sheets in each cut-off cavity.

[0011] As a further preferred scheme of the utility model, the Ku wave band slow wave circuit structure adopts a Hughes type coupled cavity structure.

[0012] As a further preferred scheme of the utility model a Ku band slow wave circuit structure, the first load combination and the second load combination all adopt beryllium oxide + titanium dioxide ring load porcelain.

[0013] As a further preferred scheme of the utility model a Ku band slow wave circuit structure, the cavity adopts the absorption small porcelain coupled with the high frequency loss material filled in the main cavity side wall slot.

[0014] Compared with the prior art, the utility model has the following technical effects:

[0015] 1, a Ku band slow wave circuit structure of the utility model, by input section, first load combination, intermediate section, second load combination and output section welding composition, under the premise of guaranteeing power output, the bandwidth can satisfy the requirement slow wave circuit structure, the present application adopts hughes type coupling cavity structure, and the cavity height, slot angle size, drift tube gap and the like parameters are designed to guarantee that the slow wave circuit has sufficient bandwidth, and the oscillation suppression technology is used to guarantee the reliability of the slow wave circuit structure, and the slow wave circuit structure of Ku band wideband high power traveling wave tube can be applicable, and the requirement that the pulse output power 60kW in 2GHz bandwidth is realized in Ku band is satisfied.

[0016] 2, the utility model adopts the simulation technology to design the cavity structure with sufficient bandwidth, adopts the dispersion combination technology to design the intermediate section structure to adjust the in-band gain, adopts the phase velocity jump technology to design the output section to improve the electron efficiency, the oscillation suppression technology is adjusted, and the matching condition of the load and input section, intermediate section and book output section is adjusted to suppress the in-band oscillation and adopts the sideband absorption technology to suppress the sideband oscillation.

[0017] 3, the utility model passes through the optimization cavity size, and the working bandwidth satisfies the requirement of traveling wave tube use, and the load porcelain size is optimized, and the load porcelain with high absorption rate and good thermal conductivity is used, and the matching of the load combination is good, so that the output power satisfies the requirement of traveling wave tube, and the sideband absorption method is used to suppress the sideband oscillation to improve the reliability of the slow wave circuit, and finally realizes the Ku band slow wave circuit structure satisfying the use of traveling wave tube, and through the whole tube actual measurement, the performance parameter satisfies the index requirement. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the structure schematic view of the utility model hughes structure coupling cavity piece;

[0019] Figure 2 It is the dispersion characteristic simulation result of the utility model;

[0020] Figure 3 It is the utility model wave interaction simulation model;

[0021] Fig. 4 (a) is the power simulation result of the utility model center frequency point;

[0022] Figure 4 (b) is the gain simulation result of the center frequency point of the utility model;

[0023] Figure 5 is the output power curve of the utility model;

[0024] Figure 6 is the input section structure diagram of the utility model;

[0025] Figure 7 is the intermediate section structure diagram of the utility model;

[0026] Figure 8 is the output section structure diagram of the utility model;

[0027] Figure 9 is the load combination structure diagram of the utility model;

[0028] Figure 10 is the position diagram of the absorbing small porcelain on the cavity of the utility model;

[0029] Figure 11 is the slow wave circuit structure diagram of the utility model. DETAILED DESCRIPTION

[0030] The technical scheme of the utility model will be further described in detail in combination with the drawings:

[0031] The technical scheme in the embodiments of the utility model will be clearly and completely described in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by the ordinary skilled in the art without creative labor belong to the protection scope of the utility model. The utility model will be described in detail according to the drawings and preferred embodiments, and the purpose and effect of the utility model will become more apparent. It should be understood that the specific embodiments described herein are only used to explain the utility model, and do not limit the utility model.

[0032] The wideband slow wave circuit structure of the utility model with the pulse output power reaching 60kW in Ku wave band can be used as the component part of the kilowatt-level high-power traveling wave tube.

[0033] The slow wave circuit structure provided by the patent has superior performance and strong innovation, and is a slow wave circuit structure applicable to Ku-band broadband high-power traveling wave tubes.

[0034] The slow wave circuit design technology: simulation technology is used to design a cavity structure with sufficient bandwidth, dispersion combination technology is used to design the middle section structure to adjust the in-band gain, and phase velocity jump technology is used to design the output section to improve the electron efficiency; oscillation suppression technology: adjusting the matching of the load and the input section, the middle section and the output section to suppress the in-band oscillation, and using sideband absorption technology to suppress the sideband oscillation. The patent proposes a Ku-band broadband slow wave circuit structure, which realizes the requirement of 60kW pulse output power within 2GHz bandwidth in Ku-band.

[0035] In order to achieve the above purpose, the technical scheme adopted by the present application is: according to the index requirements of the traveling wave tube project, a slow wave circuit structure meeting the bandwidth requirement is designed. The slow wave circuit structure of the patent comprises an input section, a middle section, an output section and a cutoff load combination. The patent ensures that the other indexes of the traveling wave tube meet the requirements on the basis of realizing wide bandwidth and high power.

[0036] In order to guarantee the electrical parameter performance of the traveling wave tube, the slow wave circuit structure needs to meet the output power, working bandwidth and working stability of the traveling wave tube in design. The patent starts from the following aspects: on the one hand, according to the parameter requirements, the slow wave circuit is preliminarily designed, then optimized by MTSS simulation software, and finally verified by whole tube application; on the other hand, through structure process design, the slow wave circuit structure has high reliability when working, and is verified by traveling wave tube working.

[0037] In view of the requirement of generating 60kW pulse output power within 2GHz bandwidth in Ku-band, the slow wave structure of the patent is designed by using the Huo's type coupling cavity to realize the slow wave structure, and the structure of the coupling cavity piece of the Huo's structure is as shown in Figure 1 .

[0038] The broadband coupling cavity traveling wave tube requires that the slow wave circuit structure has flat dispersion characteristics, and also has sufficient coupling impedance and low loss to ensure the interaction efficiency. The patent adopts the method of increasing the cold passband to expand the working bandwidth, that is, the cold passband is increased by changing the size of the coupling cavity structure, and at the same time, the factors such as power capacity and electron efficiency are considered.

[0039] According to the technical requirements, the basic size of the cavity is calculated, the phase shift is scanned by the MTSS simulation software, the slow wave circuit structure dispersion characteristic curve is obtained, and the structure size is optimized from the aspects of power capacity and heat dissipation performance, and finally the slow wave structure dispersion curve is selected as shown in Figure 2 The cold passband is about 4.5GHz, which is more than 2 times of the working frequency band, and can meet the project index requirements.

[0040] The appropriate number of cavities (14 cavities in the input section + 14 cavities in the middle section + 18 cavities in the output section) is selected, the edge frequency oscillation of the traveling wave tube is suppressed by using the loss button, and the dispersion characteristics are input into the MTSS software to calculate the slow wave system. The wave interaction simulation model is shown in Figure 3, Figure 4 (a) is the power simulation result of the center frequency point of the utility model; Figure 4 (b) is the gain simulation result of the center frequency point of the utility model; Figure 5 The output power curve of the utility model is shown in Figure 5; from the simulation result, the minimum output power in the 2GHz bandwidth is 68kW, which meets the design requirements.

[0041] As shown in Figure 6 and Figure 7 , the input section and the middle section are welded by the cavity 1 and the cavity piece 1, and the absorbing porcelain is loaded in each cavity; as shown in Figure 8 , the output section is welded by the cavity 1, the cavity 2, the cavity 3, the cavity piece 1, the cavity piece 2 and the cavity piece 3, and the absorbing porcelain is loaded in each cavity.

[0042] Load combination: the cut-off load adopts beryllium oxide + titanium dioxide ring-shaped load porcelain, which reduces the processing difficulty and improves the heat dissipation capacity under the high-power state. The size of the cavity and the load porcelain is corrected by cold measurement, and the standing wave is improved by matching different sizes. The load combination structure is shown in Figure 9 .

[0043] The load combination is composed of 2 cut-off cavities, 1 cut-off cavity piece, 2 coupling large cavity pieces and 3 load porcelains in each cut-off cavity.

[0044] Oscillation suppression: the position diagram of the absorbing porcelain on the cavity is shown in Figure 10 , the coupling cavity traveling wave tube adopting the Hughes structure is prone to edge band oscillation, especially the upper cutoff frequency oscillation is its inherent characteristic, and the edge band absorbing method is adopted to suppress the edge band oscillation. That is, the absorbing porcelain with high-frequency loss material is coupled by slotting the side wall of the main cavity, the small cavity absorbs the high-frequency energy of the upper cutoff frequency, and the effect of suppressing the upper cutoff frequency oscillation is realized.

[0045] As shown in Figure 11 , the slow wave circuit is welded by the input section, the load combination, the middle section, the load combination and the output section.

[0046] The Ku-band slow-wave circuit structure provided by the patent is verified by a large number of calculations, tests and corresponding traveling wave tubes, and has reasonable structure design and high reliability. The patent optimizes the cavity size to make the working bandwidth meet the use requirements of the traveling wave tube; optimizes the size of the load porcelain, adopts the load porcelain with high absorption rate and good thermal conductivity, and the matching of the load combination is good, so that the output power meets the requirements of the traveling wave tube; the sideband absorption method is adopted to suppress sideband oscillation to improve the reliability of the slow-wave circuit. Finally, the Ku-band slow-wave circuit structure meeting the use of the traveling wave tube is realized, and the performance parameters meet the index requirements through the whole tube measurement.

[0047] Those skilled in the art can understand that the above description is only a preferred example of the utility model, and is not used to limit the utility model, although the utility model is described in detail with reference to the foregoing examples, and those skilled in the art can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features. Any modification, equivalent replacement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model. All the technical features in the embodiment can be freely combined according to actual needs.

[0048] Finally, it should be pointed out that: the above description is only a preferred example of the utility model, and is not used to limit the utility model, although the utility model is described in detail with reference to the foregoing examples, and those skilled in the art can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features. Any modification, equivalent replacement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A Ku-band slow wave circuit structure, characterized by: It is welded by input section, first load combination, intermediate section, second load combination and output section; The input section and the intermediate section are welded by cavity 1 and cavity sheet 1, and absorbing porcelain is arranged in each cavity; The output section is welded by cavity 1, cavity 2, cavity 3, cavity sheet 1, cavity sheet 2 and cavity sheet 3, and absorbing porcelain is arranged in each cavity; The first load combination and the second load combination are both composed of two cut-off cavities, one cut-off cavity sheet, two coupling large cavity sheets and three load porcelain sheets in each cut-off cavity.

2. A Ku-band slow wave circuit structure according to claim 1, characterized in that: The Ku-band slow-wave circuit structure adopts the Hughs type coupling cavity structure.

3. The Ku-band slow wave circuit structure of claim 1, wherein: The first load combination and the second load combination both adopt beryllium oxide + titanium dioxide ring-shaped load porcelain.

4. The Ku-band slow wave circuit structure of claim 1, wherein: The absorbing porcelain with high-frequency loss material is coupled in the slot on the side wall of the main cavity.

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