JPH0636692A - Multi-cavity klystron - Google Patents

Abstract

PURPOSE:To enlarge only the movable tuning element of a resonant cavity which is made smaller as the frequency of a multi-cavity klystron becomes higher. CONSTITUTION:A metal wire 8 is wound in the helical narrow metal wire storage groove 7a of a metal wire support 7 and makes contact with the upper and lower inner wall faces of a resonant cavity 3 provided with stepped levels. The interval between the upper and lower inner wall faces 9 is enlarged by the stepped levels provided therebetween. Therefore, a movable tuning element 6 is increased in size by that enlarged dimension so that its strength can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-cavity klystron, and more particularly to a multi-cavity klystron provided with a cavity resonator having an elastic frequency tuning movable tuning element.

[0002]

2. Description of the Related Art Conventionally, some multi-cavity klystrons of this type have been used for satellite communication ground stations in the 6 GHz band.

As shown in FIGS. 2A and 2B, in the conventional multi-cavity klystron, the movable cavity 3 is movable inside the resonance cavity 3 surrounded by the cavity envelope 1 and the drift tube 2. A tuning element 6 is provided. The movable tuning element 6 is held by the tuning element support 4 and moved by the connecting rod 5.

Further, the movable tuning element 6 has a thin metal wire accommodating groove 7a spirally wound around a cylindrical metal wire support 7 having flat surfaces on both sides which are cut parallel to each other in the axial direction.
And has a structure in which a metal wire 8 having elasticity (tungsten wire or the like is conventionally used) is wound in the metal wire receiving groove 7a. Part of the metal wire 8 floating from the support 7 is in contact with the upper and lower inner wall surfaces 9 of the resonant cavity 3. The metal wire support 7 is screwed to the tuning element support 4, and the tuning element support 4 is connected to the connecting rod 5, the bellows 10 and the like.

In such a cavity resonator, the connecting rod 5
Is moved in the axial direction thereof, whereby the movable tuning element 6 is slid on the upper and lower inner wall surfaces 9 of the resonance cavity 3 to change the volume of the resonance cavity 3, that is, the amount of inductance, thereby causing resonance of the cavity resonator. The frequency is changing.

[0006]

In this conventional cavity resonator, the shape of the resonance cavity 3 becomes smaller as the frequency of the multi-cavity klystron becomes higher, so that the upper and lower inner wall surfaces 9 of the resonance cavity are inevitably produced. The distance is also narrowed, and the movable tuning element 6 is also required to be downsized. However, in order to reduce the size of the movable tuning element 6, it is necessary to make the wire diameter of the metal wire 8 thin, and there is a drawback that the mechanical strength becomes weak.

Since the high frequency current 11 flows from the upper and lower inner wall surfaces 9 of the cavity to the surface of the metal wire 8, the power loss of the metal wire 8 increases when the diameter of the metal wire 8 becomes thin, resulting in high output. There was a problem that it could not be used for Klystron.

It is an object of the present invention to provide a multi-cavity klystron in which only the variable tuning element in the resonance cavity, which becomes smaller as the frequency becomes higher, is enlarged, and the mechanical strength is increased.

[0009]

In order to achieve the above-mentioned object, a multi-cavity klystron according to the present invention is a multi-cavity klystron having a resonance cavity and a movable tuning element. Is a hollow body surrounded by a cavity envelope and a drift tube, and the opposing inner wall surface of the resonance cavity has a step provided to increase the interval,
The movable tuning element slides a metal wire against the inner wall surface of the resonant cavity facing the movable cavity, moves in the resonant cavity, and changes its volume (inductance amount).

[0010]

The inner wall surfaces of the resonant cavity facing each other are provided with steps so that the distance between them is expanded. Therefore, the variable tuning element can be increased in size by the expanded dimension thereof. Thereby, the mechanical strength of the metal wire of the variable tuning element can be increased.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. 1A and 1B are a longitudinal sectional view and a lateral sectional view showing an embodiment of the present invention.

In FIG. 1, the resonance cavity 3 is a hollow body surrounded by a cavity envelope 1 and a drift tube 2.
The resonant cavity 3 is provided with a movable tuning element 6. The movable tuning element 6 is held by the tuning element support 4 and is connected to the connecting rod 5.
Be moved by.

Further, the movable tuning element 6 has a cylindrical metal wire support 7 having flat surfaces on both sides which are cut parallel to the axial direction. The metal wire supporting body 7 has a structure in which a thin metal wire housing groove 7a is provided around the metal wire supporting body 7 and an elastic metal wire 8 is wound in the metal wire housing groove 7a. Part of the metal wire 8 floating from the metal wire support 7 on both flat surfaces of the metal wire support 7 is in contact with the upper and lower inner wall surfaces 9 of the resonance cavity 3, respectively.

The metal wire support 7 is screwed to the tuning element support 4, and the tuning element support 4 is connected to the connecting rod 5, the bellows 10 and the like. A step is provided on the upper and lower inner wall surfaces 9 of the resonance cavity 3, and the movable portion A of the movable tuning element 6 has an expanded space between the upper and lower inner wall surfaces 9 of the resonance cavity 3.

In such a cavity resonator, the connecting rod 5
Is moved in the axial direction, the movable tuning element 6 moves along the upper and lower inner wall surfaces 9 of the resonance cavity 3, the volume of the resonance cavity 3, that is, the amount of inductance changes, and the resonance frequency of the cavity resonator changes. .

[0016]

As described above, according to the present invention, since a step is provided on the upper and lower inner wall surfaces of the resonance cavity and the distance between the upper and lower inner wall surfaces of the resonance cavity in the movable region of the movable tuning element is expanded, the multi-cavity klystron can be manufactured. Even if the frequency becomes high, the structure of the movable tuning element can be made large and the mechanical strength can be increased. For this reason, the diameter of the metal wire provided in the movable tuning element can be increased to reduce the power loss of the metal wire, and it can be used for a high-power klystron.

[Brief description of drawings]

FIG. 1A is a vertical sectional view showing a cavity resonator according to an embodiment of the present invention. (B) is a cross-sectional view of the same.

FIG. 2A is a vertical sectional view showing a conventional cavity resonator. (B) is a cross-sectional view of the same.

[Explanation of symbols]

 1 cavity envelope 2 drift tube 3 resonance cavity 4 tuning element support 5 connecting rod 6 movable tuning element 7 metal wire support 7a metal wire receiving groove 8 metal wire 9 upper and lower inner wall surface 10 bellows 11 high frequency current

Claims (1)

[Claims] 1. A multi-cavity klystron having a resonant cavity and a movable tuning element, wherein the resonant cavity is a hollow body surrounded by a cavity envelope and a drift tube, The opposing inner wall surface of the resonant cavity is provided with a step so that the interval is expanded, and the movable tuning element moves in the resonant cavity by sliding a metal wire into contact with the opposing inner wall surface of the resonant cavity. , A multi-cavity klystron characterized by changing its volume (inductance amount).