JPH0443531A - Helix type travelling wave tube and its manufacture - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a helical traveling wave tube and a method for manufacturing the same, and particularly to improvements in its slow wave circuit.

(Prior art) Generally, a helix-type traveling wave tube uses an electron beam to amplify and oscillate microwaves.The conventional helix-type traveling wave tube is shown in Figs. 2 and 3. It is constructed as follows and consists of an electron gun 1, a slow wave circuit 2, and a collector 3. As is clear from FIG. 3, the slow wave circuit 2 includes a plurality of helices 5, for example three dielectric helix support rods 6, which are soldered to the inside of a pipe-shaped vacuum envelope 4. In this way, the helix 5 and the helix support rod 6 are soldered together, and techniques for increasing heat conduction are disclosed in Japanese Patent Application Laid-open No. 54-104283 and Japanese Patent Application Laid-Open No. 56-50.
It is disclosed in Japanese Patent Application Laid-open No. 611, Japanese Patent Application Laid-Open No. 56-50612, and Japanese Patent Application Laid-Open No. 57-98958. The brazing material layer 7 is formed by plating, sputtering, etc., or by applying a powdered brazing material.

(Problems to be Solved by the Invention) In the conventional wax-type traveling wave tube as described above, when the amount of brazing material in the brazing material layer 7 is small, the helix 5
If the connection with the wax support rod 6 is not made,
The bonding area is small and the desired improvement in heat conduction cannot be achieved. On the other hand, if the amount of brazing material in the brazing material layer 7 is too large, the brazing material will flow into the helix support rod 6, causing a discontinuity in the high frequency transmission line, and the high frequency will be reflected at this discontinuous portion. This may cause unstable operation. Furthermore, since the bonding area between the helix 5 and the wax support rod 6 becomes larger, thermal conductivity is improved, but the influence of the dielectric material of the wax support rod 6 becomes greater in terms of high frequencies, resulting in increased loss. Further, due to variations in the amount of brazing material and changes in the thickness of the brazing material layer 7 before and after brazing, variations in fitting into the vacuum envelope 1 occur.

It is an object of the present invention to provide a helical traveling wave tube that can uniformly and easily control the amount of brazing filler metal, and that can stably braze without generating excess solder flow, and a method for manufacturing the same. purpose.

[Structure of the Invention] (Means for Solving the Problems) The present invention is characterized in that a groove in the longitudinal direction of a metal wire is formed on the surface of the helix to be joined to the wax support rod, and this groove is filled with a brazing material. It is a helix type traveling wave tube that is soldered together.

Further, in another invention, a groove in the longitudinal direction of the metal wire is formed in advance on the surface of the helix to be joined to the wax support rod, and a layer of brazing material is formed in this groove, and after the metal wire is inserted into the vacuum envelope, This is a method for manufacturing a helical traveling wave tube that is heat-soldered.

(Function) According to the present invention, the amount of brazing metal can be made constant, and brazing can be stably performed without unnecessary flow of solder over the entire circumference.

(Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings, but since this invention is an improved slow-wave circuit of a traveling wave tube, only the slow-wave circuit will be described. do.

That is, the slow wave circuit of the helical traveling wave tube according to the present invention is constructed as shown in FIG. A helix 5 formed by winding a ribbon-shaped metal wire into a coil along the tube axis is disposed, and this helix 5 is supported and fixed to a plurality of dielectric members, for example, three, by wax support rods 6.

Furthermore, a longitudinal groove 8 made of metal wire is formed in the center of the surface of the helix 5 to be joined to the wax support rod 6, and this groove 8 is further filled with a brazing material 9. Note that each helix support rod 6 is fixed to the inner surface of the vacuum envelope 4.

When assembling, a longitudinal groove 8 is formed in advance in the ribbon-shaped metal wire constituting the helix 5, and this groove 8 is
Fill with brazing filler metal 9. In order to fill the brazing material 9, powdered brazing material is applied to the outer surface of the helix 5 and excess brazing material is wiped off, or at least after the brazing material 9 is attached to the outer surface of the helix 5 by plating, sputtering, etc. , the excess brazing material is removed by polishing the outer surface of the helix 5.

A ribbon-shaped metal wire with a groove 8 and a brazing material 9 attached thereto is wound into a coil to form a helix 5 [7] This helix 5 is supported and fixed to three dielectric members by wax support rods 6 to form a pipe shape. Insert into vacuum envelope 4. Thereafter, the helix 5 is bonded and fixed to the three wax support rods 6 by heat soldering.

In this case, of course, the brazing material flows from the groove 8 to the contact surface between the helix 5 and the wax support rod 6, and bonding is also performed at the contact surface, but by determining the width and depth of the groove 8, The amount of brazing material can be made uniform and easily controlled, and it is possible to prevent excessive protrusion in the width direction of the ribbon-shaped metal wire. In this way, the amount of brazing material can be made constant, and brazing can be performed stably without unnecessary flow of solder over the entire circumference.

Therefore, no high frequency discontinuity occurs. Also, braze the helix 5 and hem/sock support rod 6 at the front.
The helix support rod 6 and the vacuum envelope 4 do not change in assembly dimensions before and after brazing due to changes in the thickness of the brazing material 9 because they are in close contact with each other on the surface without the brazing material 9. It is easy to manage the fitting with the

The traveling wave tube of the present invention has the same structure as the conventional example (FIG. 2) except for the slow wave circuit, so a detailed explanation will be omitted.

[Effects of invention.

According to this invention, a groove in the longitudinal direction is formed in the ribbon-shaped metal wire constituting the helix, and a brazing material layer is formed in this groove, so that the amount of brazing material can be made constant.
Brazing is performed stably without unnecessary flow of solder over the entire circumference.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the main part (slow wave circuit) of a helix type traveling wave tube according to an embodiment of the present invention, and FIG. 2 is a schematic vertical sectional view showing the entire conventional helix type traveling wave tube. , 3rd
The figure is a longitudinal sectional view showing the main part (slow wave circuit) of a conventional helical traveling wave tube. 4... Vacuum envelope, 5... Helix, 6... Helix support rod, 8... Groove, 9... Brazing material. Applicant's agent Patent attorney Takehiko Suzue ＼ Figure 1 Figure 3

Claims (2)

[Claims] (1) In a helix-type traveling wave tube in which a helix formed by winding a ribbon-shaped metal wire in a coil shape is supported and fixed inside a pipe-shaped vacuum envelope by a plurality of dielectric helix support rods, the above-mentioned helix A helix type progression characterized in that a groove in the longitudinal direction of the metal wire is formed on the surface to be joined to the helix support rod, and a brazing material is further adhered to the groove and brazed to the helix support rod. Wave tube. (2) In a method for manufacturing a helix type traveling wave tube in which a helix is supported and fixed by a plurality of dielectric helix support rods and inserted into a pipe-shaped vacuum envelope, the helix is bonded to the helix support rod in advance. A method for manufacturing a helical traveling wave tube, comprising forming grooves in the longitudinal direction of the metal wire on the surface, adhering a brazing material to the grooves, inserting the metal wire into the vacuum envelope, and then heat soldering.