JPS62229637A - High power klystron - Google Patents

Abstract

PURPOSE:To make it possible to measure the tuning curve also in the middle cavity beforehand by making the loop position at the coaxial circuit with a loop for measuring the tuning frequency mounted on the external wall of a cavity variable. CONSTITUTION:The cavity wall 13 constituting a cavity is connected with one end of a side-tube 19 in which a coaxial line 20 arranged to be freely displaceable in its axial direction is inserted so as not to contact with the side- tube. An end part of this coaxial line is connected with a loop 21 which protrudes slightly into the internal wall part of the cavity an thereby the coaxial line is coupled with the cavity. That is to say, this coaxial line 20 constitutes a coaxial circuit 18 with the loop for measuring the tuning frequency. The tuning curve of each cavity is measurable by applying high frequency power from the loop 21 connected with the end part of the coaxial line 20 to within the cavity under this condition and observing a sweep reflected waveform generated within the cavity by this high frequency power.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to high power klystrons, and more particularly to the construction of cavity resonators.

Conventional technology High-power klystrons, especially multi-cavity talistrons, have features such as high efficiency, high gain, and relatively easy handling compared to other microwave tubes, and are currently used in communications, broadcasting, and other applications. It is used in various fields.

An example of a general multi-cavity klystron is schematically shown in FIG. According to the diagram, the multi-cavity talistron is
An input cavity 4, intermediate cavities 5, 6, 7, and an output cavity 8 are arranged from upstream to downstream of the electron beam 3 from the electron gun section 1 to the collector section 2.

Furthermore, one end of an output waveguide 9 is connected to the output cavity 8, and the other end of the output waveguide 9 has an output window 10. An input coaxial circuit 11 is connected to the input cavity 4 .

Further, although the illustrated klystron is of a five-cavity type, a multi-cavity type klystron usually includes four to six cavity resonators.

In such a multi-cavity klystron, a high frequency input signal is applied to the input cavity 4 via the input coaxial circuit 11, and the electron beam 3 is velocity-modulated by the high frequency. Furthermore, the focusing effect of the electron beam is strengthened while being tuned by intermediate cavities 5, 6, 7, and its modulation becomes stronger as it goes downstream.

As a result, the high frequency amplified from the output cavity 8 can be taken out of the tube via the output waveguide 9 and the output window 10.

Many of the multi-cavity type talistrons described above are of variable frequency type, and each of the multi-cavity talistrons is equipped with a frequency variable mechanism 12 in order to obtain a desired operating frequency.
is installed. FIG. 3 shows a cross-sectional view of an intermediate cavity resonator including the frequency variable mechanism 12. As shown in FIG.

According to FIG. 3, the structure of the intermediate cavity resonator of the multi-cavity klystron includes an outer conductor 14 constituting a cavity 13,
The inner conductor 15 is disposed within the outer conductor so as to be freely displaceable in the axial direction so as not to contact the outer conductor 14, thereby forming a frequency variable mechanism.

The outer conductor 14 has two wires facing each other from both sides.
A book drift tube 16 penetrates. The outer wall of the outer conductor is hermetically coupled to the outer end of the inner conductor 15 via the bellows 17 so that the inside of the talistron and the cavity 13 are maintained in a vacuum.

When the inner conductor 15 is moved in its axial direction in this state, the tuning frequency of the cavity resonator changes. There are various types of frequency tuning adjustment methods, such as high-gain type, high-efficiency type, and wide-band type, depending on the design policy of the klystron. The tuning adjustment method is shown in the explanatory diagram of FIG.

In the figure, the vertical axis indicates high frequency output, and the horizontal axis indicates frequency. Furthermore, the input cavity is set as ■, and the five cavities are numbered and displayed at the position of each tuning frequency. Further, curve A shows the band characteristic when the signal is small, and curve B shows the band characteristic when the signal is large.

According to this figure, the input cavity ■ and the output cavity ■ are tuned near the center of the band, and the intermediate cavity ■ is tuned to the lower frequency side.
The intermediate cavities ■■ are each tuned to the higher frequency side.

Furthermore, in order for the multi-cavity talistron to achieve the necessary instantaneous band characteristics, in addition to adjusting the tuning frequency of the multi-cavity resonator as described above, it is necessary to adjust the Q of the multi-cavity resonator. Values need to be adjusted.

However, at present, regarding the adjustment of the Q value of multi-cavity,
Since it varies depending on the size of the loop at the tip of the input coaxial circuit in the input cavity and the size of the iris of the output cavity, it is adjusted while emitting an electron beam when the Talistron product is completed. Fixed to an appropriate value.

Conventionally, in such a multi-cavity talistron,
Sometimes, depending on the type of pipe, the second cavity, which corresponds to the intermediate cavity 5 in Fig.
Although a dummy load may be connected to the cavity to flatten the band characteristics, generally no load circuit is connected to the intermediate cavity because there is no need to extract high-frequency output. In particular, in FIG. 2, the third and fourth cavities corresponding to intermediate cavities 6.7 are unloaded because the higher the Q, the better the characteristics as a talistron.

For reasons beyond the problems that the invention aims to solve, when adjusting the band characteristics of such a high-power klystron, it is necessary to emit an electron beam. Even if the required tuning frequency width is not satisfied due to a defect, this will not be noticed at the manufacturing stage. Therefore, only after the Talistron has been assembled to a state where it can emit an electron beam, ejects the electron beam, and adjusts it, does it become clear that one of the cavities does not meet the required tuning frequency width, etc., as described above. You can notice that. If this were to happen, the drawback was that many of the manufacturing processes up to that point would all go to waste.

However, since the lubrication of multiple cavities to obtain the necessary band characteristics is often known in advance, each cavity's tuning curve (the relationship between the tuning position and the tuning frequency) can be used to adjust the band characteristics. If you know this beforehand, you can adjust each air conditioner when manufacturing the product. If you do so, you can significantly reduce the time required to adjust the bandwidth after the klystron product is completed. Focusing on this point, in the conventional Talistron shown in Fig. 2, the input cavity 4 and output cavity 8 are equipped with load circuits, so the tuning curve can be measured by observing the swept reflection waveform. However, the problem with the intermediate cavity 5.6.7 is that it is impossible to measure the tuning curve because there is no load circuit and the cavity is in a completely closed state.

SUMMARY OF THE INVENTION Therefore, the present invention solves the above-mentioned structural problems of conventional high-power klystrons, and provides a high-power klystron that makes it possible to measure a tuning curve in advance even in an intermediate cavity.

Means for Solving the Problems An electron gun that emits an electron beam, a collector that captures the electron beam from the electron gun, and an interaction between the electron beam and electromagnetic waves between the electron gun and the collector. In a high-power klystron equipped with a high-frequency circuit section consisting of a plurality of cavities that perform an action, an intermediate cavity located between the input cavity on the electron gun side and the output cavity on the collector side. At least one cavity of the body is
A coaxial circuit with a loop for measuring the tuned frequency is attached to the outer wall of the cavity via a side pipe and a bellows, and the position of the loop can be varied in the coaxial circuit inside the cavity or inside the side pipe.

Psychologically, if at least one of the intermediate cavities has a coaxial circuit with a loop for measuring the tuned frequency, which is attached to the outer wall of the cavity via a bellows, , as well as the input cavity and the output cavity, a load circuit is now provided. Therefore, it is possible to measure the tuning curve by observing the swept reflection waveform inside the cavity in the same way as the input cavity and the output cavity.

Furthermore, since the coaxial circuit with a loop for measuring the tuning frequency is configured such that the position of the loop can be varied inside the cavity or inside the side tube, after measuring the tuning curve, the coaxial circuit with the loop is adjusted in the direction in which the bellows is extended. Vary the position of.

In other words, the coaxial circuit is drawn into the side tube from inside the cavity and is housed within the side tube. Therefore, since the coupling between the coaxial circuit and the cavity becomes weak, the presence of this coaxial circuit hardly reduces the Q of the cavity.

According to the present invention, in a high-power klystron, each tuning frequency of the input cavity, output cavity, and intermediate cavity can be measured in advance. frequency relationship) can be measured. For this reason, it is possible to adjust the multi-cavity at the time of manufacturing the product. Furthermore, cavity components that do not satisfy the required tuning frequency width due to manufacturing problems can be discovered and replaced during product manufacture.

Therefore, as in the past, when the talistron is assembled to a state where it can emit an electron beam, it is necessary to emit the electron beam and adjust the band characteristics before any of the cavities may be tuned to the required level due to manufacturing defects. You will no longer notice that the frequency width is not satisfied. Therefore, according to the present invention, the manufacturing yield of klystrons is improved, and
The time and expense required for band adjustment can be significantly reduced.

Embodiment Next, an embodiment of a high-power klystron according to the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of the intermediate cavity of a high power klystron embodying the present invention. In the figure, the structure of the cavity 13 and its frequency variable mechanism, excluding the coaxial circuit with a loop for measuring the tuning frequency attached to the cavity according to the present invention, is basically the same as the conventional intermediate cavity resonator structure shown in FIG. Since they are the same, the same reference numbers will be given to the same parts and the explanation will be omitted.

According to FIG. 1, the structure of the cavity resonator of the multi-cavity talistron is such that a side pipe 19 is attached to the cavity wall 13 constituting the cavity.
A coaxial line 20 is inserted into the side tube 19 so as to be able to bend freely in the axial direction so as not to contact the side tube 19 . A loop 21 is connected to the tip of the coaxial line 20, and the loop 21 is connected to the coaxial line 20 in the illustrated state.
The tip protrudes slightly from the inner wall of the cavity to connect the coaxial line and the cavity. That is, this coaxial line 20 constitutes a coaxial circuit with a loop 18 for measuring the tuning frequency.

Furthermore, the tip of the side tube 19 is hermetically coupled to the outer conductor flange of the coaxial line 20 via a bellows 22 so as to maintain a vacuum inside the Talistron and the coaxial line.

In such a state, the tuning curve of the multi-cavity can be measured by applying a high frequency wave into the cavity from the loop 21 at the tip of the coaxial line 20 and observing the swept reflection waveform generated within the cavity by the high frequency wave. can.

In this embodiment, a load circuit is provided for the intermediate cavity of the multi-cavity klystron in the same way as for the input cavity and the output cavity.
This makes it possible to easily measure the tuning curve of a multi-cavity Talistron.

After the measurement, the coaxial line 20 is moved in the axial direction to extend the bellows 22. As a result, the loop 21 of the coaxial line 20 that had been slightly protruding toward the inner wall of the cavity is housed within the side pipe 19, and the coupling between the coaxial line and the cavity becomes very weak. Therefore, the coaxial line does not affect the cavity characteristics during operation of the klystron and hardly reduces the Q of the cavity.

As described above, according to the present invention, in a high-power klystron, each tuning frequency of the input cavity, output cavity, and intermediate cavity can be measured in advance.
The tuning curve (relationship between tuning and tuning frequency) of the multi-cavity Talistron can be measured. For this reason, it is possible to adjust the multi-cavity at the time of manufacturing the product. Furthermore, it is also possible to discover and replace cavity components that do not satisfy the required tuning frequency width due to manufacturing defects during product manufacture.

Therefore, as in the past, when the klystron is assembled to a state where it can emit an electron beam, the electron beam is emitted and the band characteristics are adjusted. You will no longer notice that the frequency width is not satisfied. Therefore, according to the present invention, the manufacturing yield of Klyslon can be improved, and the time and cost required for band adjustment can be significantly reduced.

Furthermore, it also has the great advantage of reducing manufacturing costs.

The number of cavities to which the coaxial circuit with a loop for measuring the tuned frequency is attached or the variable mechanism for housing the coaxial line in the side tube can be changed as appropriate depending on the size and shape of the multi-cavity talistron. .

Effects of the invention As is clear from the above explanation, according to the present invention,
In high-power klystrons, the multi-cavity tuning curve of multi-cavity klystrons can be measured at the product manufacturing stage. As a result, the frequency band characteristics can be adjusted during the klystron manufacturing stage, resulting in a high manufacturing yield and a significant reduction in the time and cost required for adjusting the band characteristics. 17, it also has the effect of lowering the manufacturing cost of high-power klystrons.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the cavity of a high-power klystron according to the present invention; FIG. 2 is a diagram illustrating the general configuration of a multi-cavity talistron, which is a high-power klystron; The figure is a sectional view of the cavity of a conventional high-power klystron, and FIG. 4 is an explanatory diagram of the tuning method of each cavity of the talistron. (Main reference numbers) 1. Electron gun section, 2. Collector section, 3. Electron beam, 4. Input cavity, 5.6.7. Intermediate cavity 1, 8. Output cavity. , 9... Output waveguide, 10... Output window, 11... Input coaxial circuit, 13... Cavity,
14...Outer conductor, 15...Inner conductor, 16...
Drift tube, 17... Bellows, 18... Coaxial circuit with loop, 19... Side tube, 20... Coaxial line,
21...Loop, 22...Bellows, A...Bandwidth characteristics for small signals, B...Bandwidth characteristics for large signals, ■...Input cavity tuning position, ■...Second cavity tuning position, ■... 3rd cavity tuning position, ■... 4th cavity tuning position, ■... Output cavity tuning position, Figure 2 -, J 4... Input chamber 'l'1liq 5,
6,7.・Intermediate cavity 8... Output cavity
9. Dorikekkei tube 10. Shirikimado
11.. Input coaxial circuit 12. Circumference and skin number change mechanism Fig. 3 13.. Cavity 14.. Outer conductor 15...
Inner conductor 16... Drift tube 17...
Bellows Fig. 4 8-...Small signal Pfn area special B/Large word time zone formation special note ■ Input cavity same value 1 ■ 2nd cavity ■ Same same 1m! ■・No. 3” 1st in the same country ■・No. 49” Prosecution for the same crime 1

Claims (1)

[Claims] An electron gun that emits an electron beam, a collector that captures the electron beam from the electron gun, and an interaction between the electron beam and electromagnetic waves between the electron gun and the collector. In a high-power klystron, the high-frequency circuit section includes an input cavity on the electron gun side, an output cavity on the collector side, and an output cavity between them. an intermediate cavity located at , and at least one of the intermediate cavities is
A coaxial circuit with a loop for measuring the tuned frequency is attached to the outer wall of the cavity via a side tube and a bellows, and the coaxial circuit is characterized in that the position of the loop can be varied inside the cavity or inside the side tube. A high-power klystron.