CN104134596B - The absorbing cavity device of suppression gap coupled cavity 2 pi-mode oscillation and adjustment method thereof - Google Patents

Abstract

The invention provides and a kind of suppress the absorbing cavity device of 2 pi-mode oscillations in gap coupled cavity.The double tunning absorbing cavity of high-selenium corn chamber device resonance simultaneously is in TM₁₁₀Pattern and TM₂₁₀Pattern, and it is connected to gap coupled cavity by coupled waveguide, can effectively suppress the vibration in gap coupled cavity output circuit with two non-operating modes of 2 π mould field shape distributions, eliminate the unstability of the multiple-beam klystron caused by such vibration, reduce sundry spectrum level.

Description

Absorbing cavity device and debugging method for suppressing 2π mode oscillation of double-gap coupled cavity

technical field

The invention relates to the field of electric vacuum technology in the electronics industry, in particular to an absorption cavity device for suppressing 2π-mode oscillation of a double-gap coupling cavity.

Background technique

In order to expand the bandwidth of multi-beam klystrons, double-gap coupled cavities are usually used as broadband output circuits. Due to the internal feedback between the two resonant cavities of the double-gap coupling cavity output circuit, under certain conditions, it will cause non-working mode oscillation, resulting in a decrease in the electronic injection current and electronic injection rate of the multi-beam klystron, causing multi-beam klystron Tube ignition. In addition, under high-frequency excitation, due to the change of electron beam velocity or the existence of a small amount of inverted electrons and secondary electrons, other non-working modes will be excited to form a mixed spectrum, which reduces the quality of the output spectrum and causes the output waveguide of the transmitter to break. fire and interfere with other microwave electronic systems. Therefore, it is of great significance to suppress the oscillation of the non-working mode of the multi-beam klystron to improve the performance of the multi-beam klystron, ensure the output spectrum weight and work stability, and make it work normally in the microwave electronic system.

For multi-beam klystrons whose operating frequency is low frequency (L and S bands), a dual-gap coupled-cavity output circuit operating in π-mode is usually used. Research analysis and actual tube production show that the output circuit is easy to produce non-working mode oscillation with field distribution of 2π mode structure. In order to suppress the spurious spectrum generated by this kind of non-working mode oscillation, an absorber is usually connected to the double-gap coupling cavity, which is coupled with the double-gap coupling cavity through the coupling port, and the field shape that suppresses the resonant frequency slightly higher than the working mode is Oscillation of the TM ₀₁₀ mode of the 2π mode. The actual tube production work shows that the TM ₁₁₀ mode with a high resonance frequency and a 2π-mode field will also oscillate under certain conditions, and this oscillation will also seriously affect the stability of the multi-beam klystron in the DC state.

Contents of the invention

(1) Technical problems to be solved

In view of the above technical problems, the present invention provides an absorbing cavity device for suppressing 2π-mode oscillation of a double-gap coupling cavity and a debugging method thereof, so as to suppress non-working modes in the double-gap coupling cavity.

(2) Technical solution

The absorption cavity device for suppressing 2π-mode oscillation in a double-gap coupling cavity of the present invention includes: a double-tuned absorption cavity, which is a hollow rectangular closed resonant cavity, the first end of which is closed, and at least part of the inner cavity wall has microwave attenuating materials; the rectangular coupling waveguide , connected between the second end of the double-tuned absorption cavity and the double-gap coupling cavity, facing the coupling groove on one side of the double-gap coupling cavity, used for the double-tuned absorption cavity and the double-gap coupling cavity mode coupling. Wherein, two screw holes are set above the double-tuning absorption cavity, and through the two screw holes, the first tuning screw and the second tuning screw are inserted vertically downward into the double-tuning absorption cavity respectively, wherein the two The screw holes are all located at the center of the broad side of the double tuned absorbing cavity, so that the double tuned absorbing cavity resonates in the TM ₁₁₀ mode and the TM ₂₁₀ mode at the same time.

(3) Beneficial effects

It can be seen from the above technical scheme that the absorption cavity device and modulation method thereof for suppressing 2π-mode oscillation in a double-gap coupling cavity of the present invention have the following beneficial effects:

(1) The double-tuned absorbing cavity resonates in both TM ₁₁₀ mode and TM ₂₁₀ mode at the same time, which is connected to the double-gap coupling cavity through a coupling waveguide, so that it can effectively suppress the two gaps with 2π mode field distribution in the output circuit of the double-gap coupling cavity. Oscillation in the non-working mode eliminates the instability of the multi-beam klystron caused by this type of oscillation, and at the same time reduces the noise level;

(2) It can simultaneously load two non-operating modes with 2π-mode field distribution, and the loading on the working mode with π-mode field distribution is very small, which can ensure that while suppressing the oscillation of the non-operating mode, the multi-injection The efficiency and power-bandwidth characteristics of the klystron have little influence;

(3) The attenuation material is coated and sintered on the inner surface of the absorption cavity, which has good heat dissipation and small outgassing;

(4) The volume is small, and the preparation and assembly process is simple.

Description of drawings

Fig. 1 is a longitudinal sectional view of an absorber device for suppressing 2π-mode oscillation of a multi-beam klystron double-gap coupling cavity according to an embodiment of the present invention;

Fig. 2A is a longitudinal sectional view after the assembly of the absorption chamber device shown in Fig. 1 and the multi-injection klystron double-gap coupling chamber;

Fig. 2B is a transverse cross-sectional view of the absorbing chamber device shown in Fig. 1 assembled with the multi-beam klystron double-gap coupling chamber.

【Main components of the present invention】

100-absorption chamber device;

110-double tuned absorption cavity;

111-cavity; 112-cavity cover;

113-microwave attenuation material; 114-the first tuning screw;

115 - the second tuning screw;

120-rectangular coupling waveguide;

121-the first rectangular waveguide hole; 122-the second rectangular waveguide hole;

200-multi-beam klystron double-gap coupling cavity;

210-cavity;

211-positioning steps;

220 - upper chamber cover;

230-lower chamber cover;

240-coupling diaphragm;

241, 242-coupling groove; 243-coupling ring;

244 - output rectangular waveguide.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be noted that, in the drawings or descriptions of the specification, similar or identical parts all use the same figure numbers. Implementations not shown or described in the accompanying drawings are forms known to those of ordinary skill in the art. Additionally, while illustrations of parameters including particular values may be provided herein, it should be understood that the parameters need not be exactly equal to the corresponding values, but rather may approximate the corresponding values within acceptable error margins or design constraints. The directional terms mentioned in the embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only referring to the directions of the drawings. Therefore, the directional terms used are for illustration and not for limiting the protection scope of the present invention.

The device for suppressing the 2π-mode oscillation of the multi-beam klystron double-gap coupling cavity of the present invention can effectively suppress the oscillation of two non-working modes with 2π-mode field shape distribution in the output circuit of the multi-beam klystron double-gap coupling cavity, eliminating The instability of the multi-beam klystron caused by such oscillations reduces the spurious level at the same time.

In an exemplary embodiment of the present invention, a schematic cross-sectional view of an absorbing cavity device for suppressing 2π-mode oscillation of a multi-shot klystron double-gap coupled cavity is provided. FIG. 1 is a schematic cross-sectional view of a device for suppressing 2π-mode oscillation of a multi-beam klystron double-gap coupling cavity according to an embodiment of the present invention.

As shown in Figure 1, the absorption cavity device 100 of this embodiment includes: a double-tuned absorption cavity 110, which is a hollow rectangular resonant cavity; a rectangular coupling waveguide 120, connected to the double-tuned absorption cavity 110 and the multi-beam klystron double-gap coupling cavity 200, facing the coupling slot on the side of the multi-jet klystron double-gap coupling cavity 200, is used for the mode coupling between the double-tuned absorbing cavity 110 and the multi-jet klystron double-gap coupling cavity. Wherein, the double-tuned absorber 110 resonates in the TM ₁₁₀ mode and the TM ₂₁₀ mode simultaneously.

In this embodiment, the double-tuned absorber 110 resonates in the TM ₁₁₀ mode and the TM ₂₁₀ mode at the same time, which can effectively suppress the oscillation of the two non-operating modes with 2π mode field distribution in the multi-beam klystron double-gap coupling cavity 200 , to eliminate the instability of the multi-beam klystron caused by this type of oscillation, and reduce the noise level at the same time.

Each component of the absorber device 100 and the double-gap coupling cavity 200 of this embodiment will be described in detail below.

Please refer to FIG. 1 , the double-tuned absorption chamber 110 includes: a chamber body 111 and a chamber cover 112 . The cavity body 111 and the cavity cover 111 together form a hollow rectangular resonant cavity.

It should be noted that the size of the rectangular resonant cavity is related to the frequency that the multi-beam klystron double-gap coupling cavity needs to absorb two non-working modes. Those skilled in the art can design the length, width and height parameters of the rectangular resonant cavity according to different operating frequencies, which will not be described here again.

A sintered microwave attenuating material 113 is coated on the closed end of the cavity cover 111 of the double-tuned absorbing cavity and the cavity body 112 of the double-tuned absorbing cavity and the cavity wall on the surrounding surface near the closed end. The microwave attenuating material 113 is FeSiAl attenuating material. Of course, other types of attenuating materials can also be used in the present invention, as long as they satisfy relative permittivity δ and loss tangent Δ: 20≤δ≤25, 0.6≤Δ≤0.8. The ratio of the length Ls of the microwave attenuating material coated along the long side of the double-tuned absorbing cavity to the length L of the long side of the double-tuned absorbing cavity satisfies: 0.6≤L _s /L≤0.8.

It should be noted that the larger the area coated with the sintered microwave attenuating material 113, the better, but in order to prevent the microwave attenuating material at the coupling port between the double-tuned absorbing cavity 110 and the double-gap coupling cavity 200 from affecting the main mode, in this embodiment, The microwave attenuating material 113 is only coated on part of the double tuned absorbing cavity 110 . In addition, it should be clear to those skilled in the art that as long as part of the area of the double-tuned absorbing cavity 110 is coated with the microwave attenuating material, it does not have to strictly meet the area and area mentioned in this embodiment.

Fig. 2A is a longitudinal sectional view of the absorption chamber device of this embodiment and the multi-beam klystron double-gap coupling chamber assembled. Fig. 2B is a transverse cross-sectional view of the absorbing chamber device shown in Fig. 1 assembled with the multi-beam klystron double-gap coupling chamber. The shape and structure of the coupling waveguide 120 will be described below with reference to FIG. 2A and FIG. 2B .

As shown in Figure 2A and Figure 2B, a second rectangular waveguide hole 122 is opened on the right side of the multi-beam klystron double-gap coupling cavity 200 corresponding to the coupling groove. In the outer direction of the tube double-gap coupling cavity 200, the width of the wide side gradually increases. The second rectangular waveguide hole 122 constitutes the left rectangular waveguide portion of the rectangular coupling waveguide 120 .

As shown in FIG. 2A and FIG. 2B , the right side of the double-tuned absorbing cavity 110 is closed, and a first rectangular waveguide hole 121 is opened at a position opposite to the second rectangular waveguide hole 122 on the left side. The width value W of the wide side of the first rectangular waveguide hole 121 is constant, which is equal to the width value of the wide side at the widest point of the second rectangular waveguide hole, and the width value W satisfies the working wavelength λ The ratio W/λ ₀ of ₀ should be less than 0.4.

After assembling the absorption cavity device 100 of this embodiment and the multi-beam klystron double-gap coupling cavity 200, the first rectangular waveguide hole 121 and the second rectangular waveguide hole 122 are aligned, and their peripheral parts are hermetically fitted to form a rectangular coupling waveguide. 120.

In this embodiment, based on the required coupling degree parameter, the width of the wide side of the second rectangular waveguide hole 122 on the right side of the multi-beam klystron double-gap coupling cavity gradually increases toward the outside. Those skilled in the art should understand that the size of the rectangular waveguide hole is related to the degree of coupling, the larger the width, the greater the degree of coupling, and considering the size requirements of the entire multi-beam klystron, the width can only be achieved within a limited range. May be large. It is required that the ratio W/λ ₀ of the width W to the operating wavelength λ ₀ of the multi-beam klystron double-gap coupling cavity 200 should be less than 0.4, which is to avoid coupling other modes out of the double-gap coupling cavity.

In addition, the height d of the first rectangular waveguide hole 121 and the second rectangular waveguide hole 122 is always kept constant, and the ratio of the height _d to the height dc of the coupling groove of the multi-beam klystron double-gap coupling cavity 200 is _d /dc between 0.5 and 0.65.

Two screw holes are opened on the cover 112 of the double tuning absorption cavity, through which the first tuning screw 114 and the second tuning screw 115 are respectively inserted into the double tuning absorption cavity.

Both the first tuning screw 114 and the second tuning screw 115 are located at the center of the broadside of the double tuning absorption cavity (vertical to the axial direction of the double tuning absorption cavity), and the projections of the two on the horizontal plane fall through the center of the first rectangular waveguide hole 121 on the horizontal line.

For the first tuning screw 114, it is located near the center of the long side of the double tuning absorption cavity (parallel to the axis direction of the double tuning absorption cavity). In this embodiment, the first tuning screw 114 and the double tuning absorption cavity are not closed The distance L ₁ and the diameter D ₁ of the end satisfy: 0.28L≤D ₁ ≤0.36L, 0.4L≤L ₁ ≤0.45L, where L is the length of the long side of the rectangular resonant cavity.

The first tuning screw 114 fine-tunes the resonant frequency of the TM ₁₁₀ mode in the double-tuned absorbing cavity 110 through capacitance tuning, so that it resonates with the non-operating mode TM ₀₁₀ mode in the double-gap coupling cavity 200 with a 2π mode field distribution.

For the second tuning screw 115, it is located near 3/4 of the long side of the double tuning absorption cavity. In this embodiment, the distance L ₂ between the second tuning screw 115 and the unclosed end of the double tuning absorption cavity 110 is the diameter D ₂ Satisfy: 0.16L≤D ₂ ≤0.24L, 0.7L≤L ₂ ≤0.75L.

The second tuning screw 115 fine-tunes the resonant frequency of the double-tuned absorbing cavity TM ₂₁₀ mode through capacitance tuning, so that it resonates with the non-operating mode TM ₁₁₀ mode with 2π mode field distribution in the double-gap coupling cavity.

It should be noted that the depth of the two tuning screws 114 and 115 entering into the double tuning absorption cavity is determined during the later stage of debugging, and there is no specific range. As long as the double-tuned absorbing cavity resonates in both the TM ₁₁₀ mode and the TM ₂₁₀ mode at the same time after debugging. After the debugging is completed, the first tuning screw and the second tuning screw are welded to the double tuning absorbing cavity 110 , and the depth inserted therein remains unchanged.

Please refer to FIG. 2A and FIG. 2B , the multi-injection klystron double-gap output chamber 200 includes: a chamber body 210 , an upper chamber cover 220 , and a lower chamber cover 230 , and the three jointly enclose an output chamber. The output cavity is divided into a double-gap output cavity with an upper and lower structure by the coupling diaphragm 240 .

Two left-right symmetrical arc-shaped coupling grooves (241 and 242) are arranged on the radial periphery of the coupling diaphragm 240. Wherein, the arc-shaped coupling groove 241 on the right is aligned with the second rectangular waveguide hole 122 . The second rectangular waveguide hole 122 is aligned with the first rectangular waveguide hole 121 on the left side of the double-tuned absorbing cavity. A coupling ring 243 is provided at the position of the left arc-shaped coupling slot 242 , and the power of the double-gap coupling cavity working mode passes through the coupling ring 243 and is output through the output rectangular waveguide 244 around the coupling ring.

In addition, in order to meet the needs of assembly, a positioning step 211 is provided on the side of the double-gap coupling cavity facing the tuning absorbing cavity. 122 positioning and alignment.

In this embodiment, the materials of the double tuning absorption cavity 110 and the tuning screws 114 and 115 are all oxygen-free copper. The assembly process of the absorption cavity device of this embodiment is introduced as follows: first, sintered microwave attenuating materials are coated on the relevant parts of the cavity body 111 and the cavity cover 112; Cavity 110; after that, snap the double-tuning absorbing cavity 110 into the positioning step 211 on the right side of the multi-beam klystron double-gap coupling cavity 200, align the first rectangular waveguide hole 121 with the second rectangular waveguide hole 122, and align the two Do the welding.

So far, the introduction of the absorption cavity device for suppressing the 2π-mode oscillation of the multi-beam klystron double-gap coupling cavity in this embodiment is completed.

In another exemplary embodiment of the present invention, a debugging method for the above-mentioned absorbing cavity device is also provided, the debugging method includes: changing the first tuning screw 114 and the second tuning screw 115 inserted into the double tuning absorbing cavity 110 depth, find the position where the double-tuned absorbing cavity resonates simultaneously in the TM ₁₁₀ mode and the TM ₂₁₀ mode, and after finding the position, weld the first tuning screw 114 and the second tuning screw 115 on the cavity 111 .

So far, the introduction of the debugging method of the absorption cavity device for suppressing the 2π-mode oscillation of the multi-beam klystron double-gap coupling cavity in this embodiment is completed.

So far, two embodiments of the present invention have been described in detail with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the absorption cavity device for suppressing 2π-mode oscillation of the double-gap coupling cavity and its debugging method of the present invention.

In addition, the above-mentioned definitions of each element and method are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and those of ordinary skill in the art can easily modify or replace them, for example: (1) the above-mentioned implementation For example, a multi-beam klystron double-gap coupling cavity is used as an example for illustration. The present invention is also applicable to other types of double-gap coupling cavity, which should be clear to those skilled in the art, and will not be repeated here.

In summary, the present invention makes the dual tuning absorption cavity simultaneously resonate in TM ₁₁₀ by selecting the shape and size of the absorption cavity, coating material parameters, and adjusting the diameter, location and insertion depth of the tuning screw into the double tuning absorption cavity mode and TM ₂₁₀ mode can effectively suppress the oscillation of two non-operating modes with 2π mode field shape distribution in the multi-beam klystron double-gap coupling cavity output circuit, and eliminate the multi-beam caused by such oscillation Klystron instability, while reducing the level of spurious spectrum, and at the same time loading the operating mode with π-mode field shape distribution is very small.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. the absorbing cavity device suppressing gap coupled cavity 2 pi-mode oscillation, it is characterised in that including:

Double tunning absorbing cavity (110), closes resonator cavity for hollow, rectangular, and its first end seal is closed, at least part of face of cavity wall inside it Long-pending have microwave attenuating material；

Rectangle coupled waveguide (120), is connected to the second end of described double tunning absorbing cavity (110) and described gap coupled cavity (200), between, the just coupling slot to described gap coupled cavity (200) side, for described double tunning absorbing cavity (110) and double Mode Coupling between gap coupled cavity (200)；

Wherein, described double tunning absorbing cavity (110) two screws opened above, by these two screws, respectively to described double tune The first tuning screw (114) and second tune screw (115), wherein, these two spiral shells is inserted vertically downward in humorous absorbing cavity (110) Hole is respectively positioned on the center of described double tunning absorbing cavity (110) broadside, makes this double tunning absorbing cavity (110) resonance simultaneously in TM₁₁₀Mould Formula and TM₂₁₀Pattern；

Wherein, the diameter D of described first tuning screw (114)₁, with distance L of described double tunning absorbing cavity (100) second end₁Full Foot: 0.28L≤D₁≤ 0.36L, 0.4L≤L₁≤0.45L；The diameter D of described second tune screw (115)₂, with described double tunning Distance L of absorbing cavity (100) second end₂Meet: 0.16L≤D₂≤ 0.24L, 0.7L≤L₂≤0.75L；L is that described double tunning is inhaled Receive the length on long limit, chamber.

Absorbing cavity device the most according to claim 1, it is characterised in that the first end of described double tunning absorbing cavity (110) With microwave attenuating material described in the cavity wall coating sintering near the first side surrounding.

Absorbing cavity device the most according to claim 2, it is characterised in that the relative dielectric constant of described microwave attenuating material δ, loss tangent △ meet: 20≤δ≤25,0.6≤△≤0.8.

Absorbing cavity device the most according to claim 3, it is characterised in that described microwave attenuating material is FeSiAl material.

Absorbing cavity device the most according to claim 3, it is characterised in that the coated length of described microwave attenuation meets: 0.6 ≤L_s/L≤0.8；

Wherein, L_sFor the length along described double tunning absorbing cavity long limit coating microwave attenuating material, L is described double tunning absorbing cavity The length on long limit.

Absorbing cavity device the most according to claim 1, it is characterised in that:

The second rectangular waveguide hole (122) is offered in the position that described gap coupled cavity (200) is corresponding with described coupling slot；

The second of described double tunning absorbing cavity (110) is rectified the position to described second rectangular waveguide hole (122) and offers the first square Shape waveguide aperture (121)；

Described first rectangular waveguide hole (121) and the second rectangular waveguide hole (122) alignment, its periphery seals and coordinates, constitutes Described rectangle coupled waveguide (120).

Absorbing cavity device the most according to claim 6, it is characterised in that described second rectangular waveguide hole (122) along towards The lateral direction of gap coupled cavity, the width value of broadside is gradually increased；

The width value W of described first rectangular waveguide hole (111) broadside is constant, equal to described second rectangular waveguide hole the widest part broadside Width value,

Wherein, the width value W of described first rectangular waveguide hole (111) broadside meets: W/ λ₀≤ 0.4, λ₀Couple for described double gap The operation wavelength in chamber (200).

Absorbing cavity device the most according to any one of claim 1 to 7, it is characterised in that described gap coupled cavity is The gap coupled cavity of multiple-beam klystron.

9. the adjustment method of absorbing cavity device according to any one of a claim 1 to 7, it is characterised in that including:

Adjust that described first tuning screw (114) and second tune screw (115) insert in double tunning absorbing cavity (110) is deep Degree, finds and makes this double tunning absorbing cavity (110) resonance simultaneously at TM₁₁₀Pattern and TM₂₁₀The position of pattern, find this position it After, described first tuning screw (114) and second tune screw (115) are welded on described double tunning absorbing cavity (110).