CN106872770B - The pattern discrimination and test device of Sheet beam klystron resonant cavity - Google Patents

Abstract

The invention discloses a mode discrimination and testing device for a resonant cavity of a belt-shaped klystron tube, comprising two cavity cover plates, a plug, a disturbance probe, two coaxial probes and a vector network analyzer; The two cavity cover plates are assembled to form a main structure, and a resonant cavity, an electron injection drift channel and a channel are formed in the main structure; the plug block is inserted into the groove; a through circle is formed on the plug block slot; the perturbation probe is screwed into the plug block through the circular slot, and enters the resonant cavity, so as to shift the mode frequency of the resonant cavity; the two coaxial probes approach from two ends respectively The edge of the outermost straight waveguide gap of the resonant cavity is used to excite and detect the mode field in the resonant cavity; the vector network analyzer is connected to the coaxial probe through a cable for testing and analyzing the resonance The frequency response characteristics of the cavity. The device of the invention can effectively discriminate and measure the mode of the high-frequency multi-gap resonant cavity.

Description

Mode Discrimination and Testing Device of Ribbon Klystron Resonant Cavity

technical field

The invention relates to the technical field of millimeter-wave and submillimeter-wave electric vacuum devices, and is suitable for working mode discrimination and characteristic parameter cold measurement of a planar structure multi-gap resonant cavity with a smaller geometric size.

Background technique

As a high-power, high-gain and high-efficiency microwave and millimeter-wave amplifier, the klystron also has the characteristics of stable and reliable operation and long life, which makes it widely used in scientific research, national defense construction and industry. application. From the 1940s to the early 1970s, the development of high-power single-injection klystrons was the fastest. The representative achievements were the development of extended interaction klystrons and traveling wave klystrons. The power, efficiency and bandwidth have been significantly improved. At the same time, in order to further meet the use requirements of radar and communication systems, under the premise of reducing the working voltage, the klystron can more effectively take into account the power, efficiency and frequency band characteristics. Since the 1960s, Soviet scientists began to try The multi-injection klystron was developed and succeeded first. At present, multi-injection klystrons covering the L to Ka band have been used in various mobile RF electronic systems.

Since the 1990s, with the continuous development of computer three-dimensional simulation technology and precision microfabrication capabilities, it has become possible to break through the traditional axisymmetric circular electron optical system and develop a klystron based on non-axisymmetric ribbon beam injection. This klystron is suitable for narrow-band high-power applications from L-band to G-band, such as particle accelerators, high-power microwave weapons, and nuclear magnetic resonance spectrometers with enhanced dynamic nuclear polarization. The main advantages of the strip klystron are: 1) The surface area of the interaction circuit is large, the device is easy to dissipate heat, and the power capacity is large; 2) The high-frequency circuit is an integral plane structure, which is easy to achieve high-precision precision machining and assembly. Soldering, especially in the millimeter-wave and submillimeter-wave frequency bands, has advantages (planar processing methods such as LIGA can be used). In order to improve the interaction efficiency, the high-frequency circuit of the strip klystron is usually composed of multiple plane multi-gap resonator cavities in series. secondary mode and the interval between adjacent modes is small. Therefore, whether the working mode and non-working mode in the cavity can be accurately distinguished in the process of cold measurement of the cavity of the strip injection speed regulating tube will be a key factor affecting the success of tube making.

A paper published in 1997 by researchers at Argonne National Laboratory (ANL) in the United States (Microwave Cold Tests of Planar RF Cavities, J. Chen, T. Lee, and D. Yu, Proceedings of the 1997 Particle Accelerator Conference, vol. 3, pp. 3120-3122) describes a structural solution for cold measurement of X-band dumbbell-shaped resonators, referring to FIG. 1 . According to the text, a small current loop E1 is inserted into the outer wall of the cavity, and different TM or TE modes can be excited by changing the angle between the plane of the current loop and the z-axis (along the electron injection movement direction). The current loop E1 is connected to the vector network analyzer 5 through the coaxial cable E2, and each peak on the frequency response curve obtained by single-port scanning corresponds to the resonant frequency of each mode.

The defects of the above-mentioned prior art solutions mainly include the following three aspects. First, this method can only measure single-gap resonators with low resonant frequency and large central size. There is enough space to accommodate the current loop at the end of the coaxial line, and the introduction of the current loop will not cause excessive disturbance to the distribution and mode frequency of the gap electric field. However, in the millimeter wave and submillimeter wave frequency bands, as the operating frequency continues to rise, the cavity size will also continue to decrease. For example, in the W band, the cavity gap width (along the z-axis) is usually less than 1mm, and the cavity gap height ( along the y-axis) is usually less than 2mm, at this time, the method of using the current loop excitation is not feasible. Secondly, the method of setting a current loop in the middle of the resonator to excite the working mode is effective for single-gap resonators, but because a single current loop cannot excite two or more gaps at the same time, it is necessary to test the multi-gap resonator. less effective. Furthermore, this scheme only considers the measurement of the frequency of the cavity mode that has been processed, and the discrimination between the working mode and the non-working mode is only realized by the comparison with the simulation results, which is an important factor in the actual high-frequency cold measurement process. Limited (pseudo-modes and erroneous measurement signals can interfere with mode discrimination).

SUMMARY OF THE INVENTION

(1) Technical problems to be solved

Based on the above problems, the main purpose of the present invention is to provide a mode discrimination and testing device for the resonant cavity of a strip klystron tube, so as to solve at least one of the above technical problems.

(2) Technical solutions

The technical scheme of the present invention is as follows:

The invention provides a mode discrimination and testing device for the resonant cavity of a belt-shaped klystron tube, comprising two cavity cover plates, a plug, a disturbance probe, two coaxial probes and a vector network analyzer; The two cavity cover plates are assembled to form a main structure, and a resonant cavity, an electron injection drift channel and a channel are formed in the main structure; the resonant cavity includes two cavities and at least one connecting the two cavities. a straight waveguide gap; the electron injection and drift channel runs through the resonant cavity in a direction perpendicular to the straight waveguide gap to form a rectangular channel; the first end face of the channel and one of the cavities on both sides of the resonant cavity The second end surface of the channel extends to the end of the cavity cover plate; the plug block is inserted into the channel from the second end surface of the channel, and reaches the first end of the channel. one end face; the plug block has a through circular groove; the disturbance probe is screwed into the plug block through the circular groove and enters the resonant cavity for shifting the mode frequency; the two Coaxial probes respectively protrude from both ends of the electron injection drift channel, and are close to the edge of the outermost straight waveguide gap of the resonant cavity, and are used to excite and detect the mode field in the resonant cavity; the coaxial probe The outer diameter of the probe is smaller than the height of the narrow side of the electron injection drift channel; the vector network analyzer is connected with the coaxial probe through a cable for testing and analyzing the frequency response characteristics of the resonant cavity.

The cavity cover plate and the plug block are made of oxygen-free copper material. One end of the plug block reaching the first end face of the channel is used to seal the first end face of the channel; the circular groove of the plug block sequentially includes a threaded hole, a circular hole, a tapered hole and a probe from outside to inside holes, all threaded holes, round holes, tapered holes and probe holes are located on the same axis; the disturbance probe sequentially includes a screw rod, a round rod, a tapered section and a fine probe; the screw rod, circular The rod, the tapered section and the fine probe are matched with the threaded hole, the circular hole, the tapered hole and the probe hole in sequence, so that the disturbance probe passes through the threaded hole, the circular hole, the tapered hole and the probe hole in sequence. A pinhole enters the resonant cavity. A slot is formed at the end of the disturbance probe, and the screw used for rotating the disturbance probe moves in the threaded hole of the plug block. The diameter of the micro-probe is not more than 0.2 mm. The micro-probe can continuously enter from zero to a certain position within the resonant cavity. The coaxial probe includes a metal cylindrical shell, a dielectric insulating layer and a metal wire, the metal wire is located at the center position, and its outer layer concentrically wraps the dielectric insulating layer and the metal cylindrical shell in turn; the end of the metal wire is Protruding from the dielectric insulating layer and the metal cylindrical shell. The outer surface of the metal shell of the coaxial probe is covered with insulating material.

(3) Beneficial effects

(1) The excitation and detection of the mode field in the plane single-gap or multi-gap resonant cavity of the present invention is realized by a fine semi-rigid coaxial probe. The method is simple and reliable, as long as the coaxial probe after coating the insulating layer can be guaranteed The outer diameter may be smaller than the height (along the y direction) of the narrow side of the electron injection drift channel. Relatively speaking, placing the current loop in the cavity gap is greatly limited by the size of the gap, making it difficult to apply in cavities operating in millimeter-wave and higher frequency bands. In addition, for multi-gap cavities, the method of placing the current loop only in a single gap in the middle may not be able to effectively excite the working mode, while the method of placing coaxial probes at both ends of the drift channel can effectively excite the working mode. The individual cavity modes of the axial electric field component.

(2) The complete cavity structure in the present invention is composed of two upper and lower cavity cover plates with the same structure, and the cavity is connected with the channel only on one side of the resonant cavity. The end face of the plug block acts as a side wall to seal the cavity to form a closed structure surrounding the electron injection channel. Considering that in the actual high-frequency structure of the tube body, it is also necessary to reserve this position for welding the tuning diaphragm. Therefore, compared with the existing solution, which must open holes in the upper part of the cavity gap to penetrate the current loop, this solution has a low temperature and low cost. During the measurement process, there is no need to open additional holes on the cavity, which simplifies the process and avoids frequency changes that may be caused by subsequent plugging of the holes.

(3) The present invention perturbs the electric field in the gap through the metal thin needle extending into the gap from the cavity side wall of the resonant cavity. According to the frequency change of each peak on the dual-port transmission curve, combined with theoretical and simulation analysis results The peak corresponding to the working mode can be accurately distinguished from it, which provides an experimental basis for the subsequent fine-tuning of the internal dimensions of the cavity, so that the frequency of the actual cavity meets the design requirements. Due to the large number of modes in the multi-gap resonator and the unavoidable external interference, there are many spikes on the measured S-parameter curve, and simply comparing the measured values of the vector network analyzer with the simulation results is not enough to rule out the working mode and other disturbances, and the method of using perturbation probes in this scheme effectively solves this problem.

Description of drawings

Fig. 1 is the schematic diagram of the prior art band-shaped klystron dumbbell-shaped single-gap resonant cavity cold measuring device;

FIG. 2 is a schematic diagram of a cold measurement device for a flat multi-gap resonant cavity of a strip klystron tube according to an embodiment of the present invention;

Fig. 3a is a three-dimensional structural schematic diagram of the cavity cover plate shown in Fig. 2;

Fig. 3b is a partial enlarged view of the multi-gap resonant cavity region of the cavity cover plate shown in Fig. 3a;

Figure 4a is a schematic diagram of the three-dimensional appearance and internal structure of the plug shown in Figure 2;

Figure 4b is an xy cross-sectional view of the plug shown in Figure 4a;

Fig. 5 is the three-dimensional structure schematic diagram of the perturbation probe shown in Fig. 2;

Fig. 6 is the appearance and partial sectional view of the coaxial probe shown in Fig. 2;

Fig. 7 is the electric field vector distribution obtained by simulation after the disturbance probe is inserted into the planar multi-gap resonator shown in Fig. 2;

FIG. 8 is a dual-port transmission curve obtained by simulation when the planar multi-gap resonator is cold measured as shown in FIG. 2 .

Detailed ways

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

FIG. 2 is an apparatus for discriminating and testing the mode of the planar multi-gap resonant cavity in the strip klystron according to an embodiment of the present invention. As shown in FIG. 2 , the device of one embodiment includes a cavity cover 1 (two pieces, the other piece is not shown in FIG. 2 ), a plug 2 , a disturbance probe 3 , and coaxial probes 41 and 42 , wherein The coaxial probes 41 and 42 are semi-rigid and are connected to the vector network analyzer 5 through waveguide coaxial converters and cables, respectively. In practice, two pieces of cavity cover plates 1 with identical internal structures are assembled to form a main structure, in which a resonant cavity, an electron injection drift channel and a rectangular channel 15 located on one side of the resonant cavity are formed. The disturbance probe 3 is screwed into the plug block 2 through the screw hole, and the plug block 2 is inserted into the rectangular channel 15 of the tested structure formed by the combination of two cavity cover plates 1, and is fixed and pressed on the external end face with screws. Coaxial probes 41 and 42 respectively protrude from the drift channels on both sides of the resonator, and are close to the edge of the outermost straight waveguide gap of the resonator. They are used as excitation and reception coaxial probes (the two can be interchanged) to measure the resonator. frequency response characteristics, such as S-parameters. In order to ensure good electrical conductivity, the cavity cover plate 1 and the plug block 2 are made of oxygen-free copper material. The planar three-gap resonator shown in Fig. 2 corresponds to the resonator of the high frequency structure of the actual strip klystron. It should be noted that the high-frequency circuit of the actual device often contains more resonant cavities, and the number of straight waveguide gaps in each resonant cavity may also be more than three. For the sake of clarity, only one containing three straight waveguides is drawn. The structure of the resonant cavity of the gap, that is, the three-gap resonant cavity. In addition, the number of straight waveguide gaps of the resonant cavity may also be one, and the resonant cavity in this case is a single-gap resonant cavity. The principle and device are the same as those described below when cold testing is performed on a high-frequency structure of a single gap or a resonant cavity with two or more straight waveguide gaps. The first end face of the rectangular channel 15 is communicated with one of the cavities on both sides of the resonant cavity, and the second end face of the rectangular channel 15 extends to the end of the cavity cover plate 1; the electron injection drift channel is perpendicular to the straight waveguide. The direction of the gap runs through the resonant cavity, forming a rectangular channel. The first end face of the rectangular channel 15 refers to the junction where the rectangular channel 15 communicates with one of the cavities on both sides of the resonant cavity.

As shown in Figure 3a and Figure 3b, two identical cavity cover plates 1 are combined to form a planar multi-gap resonant cavity, and the internal structure of the cavity cover plate 1 (equivalent to one-half complete cavity) are described. 11 is a rectangular drift channel along the electron injection movement direction (z direction), which runs through the planar multi-gap resonator. 12 and 13 are larger cavity structures on both sides of the resonant cavity, and the shape and size of the two are exactly the same. The cavity 13 on the cavity side of the resonant cavity is adjacent to the rectangular channel 15, and the plug block 2 is inserted into the rectangular groove. After the channel 15 is pressed against the first end surface of the rectangular channel 15 , the side wall of the closed cavity 13 is formed. A straight waveguide gap 14 connects the cavities 12 and 13 on both sides of the resonator. The width of the straight waveguide gap 14 and the period length between adjacent straight waveguide gaps 14 depend on the operating parameters of the klystron. Screws can be screwed into the screw holes 16 to press the plug block 2 on the cavity structure to ensure that the end of the plug block 2 that reaches the first end face of the rectangular channel 15 is tightly connected to the first end face of the rectangular channel 15 affixed to seal the first end face of the rectangular channel 15, thereby sealing the resonant cavity to form a closed structure surrounding the electron injection channel, effectively reducing the loss and improving the measurement accuracy of the cavity parameters. Except for the end face of the plug block 2 that is in contact with the first end face of the rectangular channel 15, the other four faces are not required to be in strict and close contact with the four faces of the groove, and the two can be slidably matched.

The working principle of the above-mentioned dumbbell-shaped planar multi-gap resonator can be briefly described as follows. If f ₁ is the cut-off frequency of the fundamental mode of the intermediate straight waveguide, and f ₂ is the fundamental mode resonance frequency of the rectangular cavity at both ends (cavity structures on both sides), then when f ₁ >f ₂ , the intermediate straight waveguide is in the cut-off state , the dumbbell-shaped resonator actually becomes two separated rectangular resonators. At this time, the distribution of the electric field Ez component in the cavity along the x direction is low in the middle and high at both ends. However, when f ₁ <f ₂ , the intermediate straight waveguide is in a conducting state, and the dumbbell-shaped resonator can be approximated as an ordinary rectangular cavity (equivalent to the two ends of the intermediate straight waveguide being closed), so the E _z component of the electric field in the cavity The distribution along the x-direction is high in the middle and low at both ends. Thus, it can be expected that for the critical state of f ₁ ≈ f ₂ , the distribution of the E _z field quantities in the straight waveguide gap of the resonator along the x direction will be nearly uniform, which corresponds to the required cavity operating state.

As shown in Figures 4a and 4b, the plug block 2 is a 'T'-shaped structure with an internal opening, the rectangular block 21 is inserted into the rectangular channel 15 of the cavity cover 1, and the dimensions of the two closely match; Two through holes 24 are symmetrically opened on the end 22 of the cavity cover 1. After the rectangular block 21 of the plug block 2 is slidably inserted into the rectangular channel 15 of the cavity cover plate 1, the through holes 24 can be connected with the cavity cover plate 1. The screw holes 16 are aligned, and a certain length of screws can be used to pass through the through holes 24 and screw them into the screw holes 16. In addition to the function of fixing the plug block 2 on the cavity cover 1, more important It is to ensure that the end of the rectangular block 21 is in close contact with the bottom surface of the rectangular channel 15 to ensure good surface contact between the two;

As shown in Figures 4b and 5, the circular groove 23 passing through the inside of the plug block 2 sequentially includes a threaded hole 231, a circular hole 232, a tapered hole 233 and a probe hole 234, all of which must be strictly located on the same axis, and The axis is required to be perpendicular to the end face of the rectangular block 21; accordingly, the disturbance probe 3 sequentially includes a screw 31, a round rod 32, a tapered section 33 and a fine probe 34, which are in turn matched with the features 231-234 inside the plug block 2, In addition, a slot 35 is opened at the end of the disturbance probe 3 for rotating the disturbance probe 3 to move in the threaded hole 231 . In terms of structure, the outer diameter of the round rod 32 on the disturbance probe 3 should be smaller than the inner diameter of the threaded hole 231 in the plug block 2, and at the same time slightly smaller than the inner diameter of the round hole 232; the taper angle of the tapered section 33 on the disturbance probe 3 is slightly It is smaller than the taper angle of the tapered hole 233 in the plug block 2 , and the outer diameter of the fine probe 34 is slightly smaller than the inner diameter of the probe hole 234 . Considering that the diameter of the fine probe 34 is usually not greater than 0.2 mm, the tapered hole 233 in the plug block 2 plays a role in guiding the fine probe 34 to smoothly penetrate into the probe hole 234, so as to avoid the mutation of the structure causing the The problem of broken probe 34. The probe hole 234 in the plug block 2 should have a certain length to limit and guide the fine probe 34 to ensure that it enters the cavity along the direction perpendicular to the end face of the rectangular block 21 . Reasonably set the lengths of the screw 31 , the round rod 32 , the conical section 33 and the fine probe 34 included in the disturbance probe 3 to ensure that within the effective stroke of the screw 31 , the fine probe 34 can start from the end face of the rectangular block 21 from zero Continuously enter a certain position in the cavity.

As shown in FIG. 6 , the coaxial probes 41 and 42 have the same structure and can be interchanged, and are respectively used to excite and detect the mode field in the resonant cavity. The coaxial probe 41 is used as an example for description below. . The coaxial probe 41 is composed of a metal cylindrical shell 411 located outside, a dielectric insulating layer 412 and a metal wire 413 located in the center. The signal of the axial electric field (along the z direction, corresponding to the working mode and the adjacent axial mode) is well excited and received. In actual use, it is better to cover the outer surface of the metal cylindrical shell 411 of the coaxial probe 41 with insulating material. At this time, the total outer diameter of the coaxial probe should be smaller than the narrow side height of the electron injection drift channel (along the y direction). , refer to Figure 2 and Figure 3a). Because the dimensions of the electron injection drift channel along the broad side (x direction) and the narrow side (y direction) are not equal, and the size of the broad side is much larger than the narrow side, when a circular probe is inserted into the drift channel, the conflicting dimensions is the narrow side height. The standing wave ratio, impedance and signal attenuation of the coaxial probes 41 and 42 in the working frequency band should meet the usage requirements.

When discriminating and measuring the modes in the resonant cavity, the physical principle is based on: tiny metal bodies will cause changes in the distribution of electric and magnetic fields in the local area, the disturbance of the electric field will reduce the resonant frequency, and the disturbance of the magnetic field will increase the resonant frequency. If the frequency is high, the variation trend of the actual frequency depends on the strength and distribution of each component of the electromagnetic field, as well as the shape and size of the metal body. The simulation results shown in Fig. 7 show that the perturbation probe that protrudes from the sidewall of the planar three-gap cavity into the central straight waveguide gap disturbs the electric field distribution near it, but the electric field direction in each straight waveguide gap remains consistent as a whole. , the cavity 2π mode does not change. As shown in Figure 8, the simulation calculation gives the S-parameter curve measured by the coaxial probe in the cold test device. The three peaks in the figure correspond to the 2π mode, the π/2 mode and the π mode from left to right. Among them, the 2π mode is the required working mode (according to different cavity designs, the π mode can also be selected as the working mode).

Referring to Fig. 7, it can be considered that the parallel electric field distribution (along the z direction) is approximately uniform in the gap between the straight waveguides of the resonant cavity in the theoretical analysis. There is an approximate relationship between the length of the gap into the intermediate straight waveguide) as follows:

In the formula, f ₀ is the resonant frequency before the cavity is disturbed, the shape factor s=d/l, d and l are the diameter and length of the thin metal needle, respectively, and E ₀ is the normalization in the cavity when the cavity is not disturbed The electric field value satisfies the relation where ε ₀ is the dielectric constant in vacuum, and the integral region of the electric field is the entire cavity.

In the process of testing the cavity, first, as shown in Figure 2, install the entire testing device. At this time, care should be taken to make the disturbance probe 3 just inside the plug, that is, as long as the disturbance probe is slightly rotated, the disturbance probe Part 3 of the fine probe 34 enters one of the cavities on both sides of the resonator. After that, move the coaxial probes 41 and 42 to gradually approach the edge of the outermost straight waveguide gap of the resonator from both sides (which can be achieved by a precise moving device), at this time, it can be observed through the vector network analyzer 5 that there are multiple peaks The S12 curve of these peaks may come from multiple resonance modes or other interferences in the cavity of the resonant cavity. Repeatedly adjust the position of the coaxial probe 41 or 42 relative to the edge of the gap between the straight waveguide of the resonator cavity and eliminate it as much as possible. And unstable interference signal, find and fix the position of coaxial probe 41 or 42 when the transmission curve with stable shape and distribution can be excited and detected (the position of the peak is basically fixed). Next, rotate the tail of the probe 3 with the help of a tool to make the fine probe 34 enter the resonator cavity. According to the analysis, the disturbance of the fine probe 34 can only cause the working mode of the resonator cavity (2π mode or π mode). The frequency shows an approximately linearly decreasing change, so the peak corresponding to the working mode can be distinguished accordingly. During this process, the number of revolutions of the perturbation probe 3 is carefully recorded to determine the entry of the fine probe 34 into the cavity of the resonant cavity. Length (for example, the pitch of M2 thread is 0.4mm/circle). On this basis, certain dimensions of the resonator cavity can be fine-tuned locally during subsequent processing, so that the peak frequency corresponding to the working mode can meet the design requirements.

In addition, the definition of each part and method in this embodiment is not limited to various specific structures, shapes or methods mentioned in this embodiment, and those of ordinary skill in the art can make certain changes or substitutions, which are specifically described below.

(1) Only the structure of the middle cavity of the klystron is involved in the device of the present invention. In klystron applications, input and output cavities are also required. Generally, the input and output cavities are provided with coupling ports on the other side of the resonant cavity opposite to the channel 15, and the coupling ports are connected to the external waveguide to form input and output cavities with waveguides. The single-port method can be used for the test of the input and output cavities with waveguides. At this time, the coaxial probes 41 and 42 can be omitted, and the vector network analyzer 5 can be directly connected through the waveguide ports, and the frequency of the working mode can be determined by the group delay curve. and external quality factor. For the non-operating mode with a large external quality factor, since its energy is mainly concentrated in the cavity, there are fewer spikes on the group delay curve, but there will still be spikes caused by spurious modes or interference, which also requires the use of the aforementioned The perturbation method of perturbation probe 3 is used to discriminate and eliminate.

(2) As shown in Figure 4b, the structure of the circular groove in the plug block 2 is complex, and the processing of one-time forming is difficult. The ends of the shaped hole 233 and the probe hole 234 are used as a part, and the remaining structure is used as another part, and then the two separately processed parts are connected by a tight fitting structure, usually without additional welding.

(3) As shown in FIG. 5 , the size of the fine probe 34 in the disturbance probe 3 is very different from that of the rest of the structure, and the diameter ratio can reach more than 10 times. It is divided into two parts for processing, the micro probe 34 is used as a separate part, and the other screw 31, round rod 32 and tapered section 33 with similar dimensions are used as another part, and a counterbore with a certain depth is machined at the front end of the tapered section 33. After that, insert the separately processed micro probe 34 into the countersunk hole of the tapered section 33 to assemble the complete disturbance probe 3. In order to ensure reliable connection, soldering should be performed between the two. High-strength tool steel can be used as the material of the disturbance probe 3 (especially the fine probe 34 ) to ensure that the overall structure is not easily deformed and bent, thereby improving the accuracy of the measurement results.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principle of the present invention, any modifications, equivalent replacements, improvements, etc. made should be included within the protection scope of the present invention.

Claims (9)

1. a kind of pattern discrimination and test device of Sheet beam klystron resonant cavity, which is characterized in that including two cavity cover boards, One chock, a disturbance probe, two coaxial probes and vector network analyzer；

Described two cavity cover board splits form main structure, resonant cavity are formed in the main structure, electronics note drift is led to Road and conduit；The resonant cavity includes two sides cavity and at least one the straight wave guide gap for connecting two sides cavity；The electronics note Drift channel runs through the resonant cavity along perpendicular to the straight wave guide gap direction, forms rectangular channel；The first of the conduit One of end face and two sides cavity of the resonant cavity are connected, and the second end face of the conduit extends to the cavity cover board End；

The chock is inserted into the conduit from the second end face of the conduit, and reaches the first end face of the conduit；It is described Chock is provided with the circular groove of perforation；

The disturbance probe is screwed in inside chock by the circular groove, and enters the resonant cavity, for making mode frequency Offset；

Described two coaxial probes are protruded into from the both ends of electronics note drift channel respectively, close to the outermost of the resonant cavity The edge in straight wave guide gap, for motivating and detecting the mode field in the resonant cavity；The coaxial probe outer diameter is less than The narrow side height of the electronics note drift channel；

The vector network analyzer and the coaxial probe are by cable connection, for testing and analyzing the frequency of the resonant cavity Rate response characteristic.

2. the pattern discrimination and test device of Sheet beam klystron resonant cavity as described in claim 1, which is characterized in that described Cavity cover board and chock are made of oxygenless copper material.

3. the pattern discrimination and test device of Sheet beam klystron resonant cavity as described in claim 1, which is characterized in that described One end that chock reaches the first end face of conduit is used to seal the first end face of the conduit.

4. the pattern discrimination and test device of Sheet beam klystron resonant cavity as described in claim 1, which is characterized in that

The circular groove of the chock from outside to inside successively include threaded hole, circular hole, bellmouth and probe aperture, all threaded holes, circular hole, Bellmouth and probe aperture are located on same axis；

The disturbance probe successively includes screw rod, round bar, conical section and fine probe；

It is described disturbance probe screw rod, round bar, conical section and fine probe successively with the threaded hole, circular hole, bellmouth and spy Pin hole matches, and the disturbance probe is made to pass sequentially through the threaded hole, circular hole, bellmouth and probe aperture into the resonance Chamber.

5. the pattern discrimination and test device of Sheet beam klystron resonant cavity as claimed in claim 4, which is characterized in that described The end of disturbance probe is provided with flat recess, and the screw rod for disturbing probe described in turn moves in the threaded hole of the chock.

6. the pattern discrimination and test device of Sheet beam klystron resonant cavity as claimed in claim 4, which is characterized in that described Fine probe diameter is not more than 0.2mm.

7. the pattern discrimination and test device of Sheet beam klystron resonant cavity as claimed in claim 4, which is characterized in that described Fine probe can be from zero continuously into from position certain in the resonant cavity.

8. the pattern discrimination and test device of Sheet beam klystron resonant cavity as described in claim 1, which is characterized in that described Coaxial probe includes metal cylinder shell, dielectric insulation layer and wire,

The wire is located at center, and outer layer successively concentrically wraps up dielectric insulation layer and metal cylinder shell；It is described The dielectric insulation layer and the metal cylinder shell are stretched out in the end of wire.

9. the pattern discrimination and test device of Sheet beam klystron resonant cavity as claimed in claim 8, which is characterized in that described The metal shell outer surface covering insulating material of coaxial probe.