JP3513039B2 - Coaxial waveguide converter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a coaxial waveguide converter connected to a microwave amplifier such as a traveling wave tube.

[0002]

2. Description of the Related Art FIG. 8 is a longitudinal sectional view showing a schematic structure of a conventional traveling wave tube 20 disclosed in, for example, Japanese Utility Model Publication No. 2-42352. Traveling wave tube 20 is generally composed of an electron gun 21, a slow wave circuit unit 22 and a collector 23. The slow wave circuit unit 22 is configured by supporting and fixing a helix 25 in a vacuum envelope 24 with a dielectric support rod 26. The traveling wave tube 2 is provided at both ends of the slow wave circuit unit 22, respectively.
Input connector 27 and traveling wave tube 20 for introducing microwave into 0
The output connector 28 for outputting the microwave amplified by is installed. The microwave input from the input plug 27 or the microwave output from the output plug 28 is, for example, as shown in FIGS. The mode is converted by the coaxial waveguide converter 1. The coaxial waveguide converter 1 includes a coaxial inner conductor 2 and one end 2 of the coaxial inner conductor 2.
It is composed of a waveguide 3 to which a is joined, and a coaxial outer conductor 4, and a fitting portion 5 of the coaxial outer conductor 4 is fitted into a waveguide hole 6 provided in the waveguide 3 by an interference fit. By being combined, the waveguide 3 and the coaxial outer conductor 4 can be maintained in an appropriate contact state, and the coaxial inner conductor 2 and the coaxial outer conductor 4 form a coaxial circuit. Also, output connector 2
As shown in FIG. 9A, reference numeral 8 denotes an outer conductor 28a, an inner conductor 28b, and a ceramic provided between the outer conductor 28a on the coaxial outer conductor 4 side of the output plug 28 and the inner conductor 28b. The output connector 28 and the coaxial waveguide converter 1 are formed of a window 29, and the outer conductor 28a is an end portion of the coaxial outer conductor 4 opposite to the waveguide 3 and an inner conductor 28b. In a state where the other end 2b of the coaxial inner conductor 2 is in contact, they are connected by an appropriate method such as a connector structure. The same applies to the connection state between the input connector 27 and the coaxial waveguide converter 1.

Next, the operation of traveling wave tube 20 will be described. The electron beam emitted from the electron gun 21 is kept at a constant radius in the helix 25. The microwave input from the input connector 27 is decelerated by the slow wave circuit unit 22,
It interacts with the electron beam kept at a constant radius along the tube axis of the traveling wave tube. As a result of the interaction, the microwave is amplified, passes through the output connector 28, is mode-converted by the coaxial waveguide converter 1, and is transmitted to an external circuit. The electron beam which has finished the work is consumed by the collector 23.

[0004]

Conventionally, when converting a microwave transmission line from a waveguide to a coaxial line or from a coaxial line to a waveguide line, the coaxial waveguide converter 1 is previously set. The coaxial portion (inner coaxial conductor 2 and outer coaxial conductor 4) and the waveguide portion (waveguide 3) are separately provided, and the coaxial inner conductor 2 is attached to the waveguide 3 and on the traveling wave tube 20. The coaxial outer conductor 4 and the waveguide 3 are fitted to each other to form the coaxial waveguide converter 1.
At this time, both fitting portions (contact portions) are structured to have an optimum contact pressure in order to reduce high frequency resistance.
Generally, the waveguide 3 is made of a soft material such as Al or Cu, while the coaxial outer conductor 4 is entirely made of a spring material such as beryllium copper, or
As shown in (a), since the fitting portion 5 of the coaxial outer conductor 4 to the waveguide 3 is made of the above spring material, when the two are connected, the guiding portion which is the fitting portion of the waveguide 3 is connected. The inner peripheral surface 6k of the wave tube hole 6 is scraped. Then, the scraped metal piece falls on the ceramic window 29 of the input connector 27 or the output connector 28 of the traveling wave tube 20, and a high frequency discharge is induced due to the fallen object, resulting in the traveling wave tube. There was a problem such as destruction.
The fitting portion 5 of the coaxial outer conductor 4 is provided with an R at the tip as shown in FIG. 10B, or a slit is provided in the axial direction of the tip as shown in FIG. 10C. There are also things that are difficult to scrape, such as by scraping. Therefore, when connecting the waveguide 3 and the coaxial outer conductor 4, the inner peripheral surface 6k of the waveguide hole 6 is mainly shaved.

The present invention has been made to solve the above problems, and in a coaxial waveguide converter in which a coaxial outer conductor and a waveguide can be separated, a fitting portion between the coaxial outer conductor and the waveguide is provided. Maintains good contact pressure with, reduces high frequency resistance, and prevents metal pieces from falling into the ceramic window that occurs when the coaxial outer conductor and waveguide are attached / detached, improving the stability of the traveling wave tube. The purpose is to let.

[0006]

According to a first aspect of the present invention, there is provided a coaxial waveguide converter in which the coaxial outer conductor portion is fitted to or fitted with the coaxial outer conductor portion of the waveguide. A protective member made of a hard material is provided.

In the coaxial waveguide converter according to a second aspect of the present invention, the hole diameter of the fitting portion of the waveguide is smaller than the hole diameter of the protective member.

In the coaxial waveguide converter according to a third aspect of the present invention, the protective member is a plate and the protective member is screwed to the waveguide.

In the coaxial waveguide converter according to a fourth aspect of the present invention, the protective member is brazed to the waveguide.

In the coaxial waveguide converter according to a fifth aspect of the present invention, the protective member is formed by forming a hole in the main body of the waveguide at the same time after a hard material is adhered and fixed to the waveguide. .

According to a sixth aspect of the coaxial waveguide converter, a protective member is press-fitted into the waveguide.

In the coaxial waveguide converter according to the seventh aspect, the protective member is a member having a hollow screw structure and is screwed to the waveguide.

In the coaxial waveguide converter according to the present invention, the hole of the fitting portion of the waveguide has a taper structure.

[0014] coaxial waveguide converter according to claim 9 is obtained by a tapered fitting portion of the coaxial outer conductor portion.

According to a tenth aspect of the present invention, the coaxial waveguide converter is such that the fitting portion of the waveguide with the coaxial outer conductor portion is hard-plated.

According to the eleventh aspect of the present invention, the coaxial waveguide converter is provided with a protective member, which is preliminarily hard-plated, on the fitting portion of the waveguide with the coaxial outer conductor portion.

According to a twelfth aspect of the present invention, in the coaxial waveguide converter, a protective member is provided at a fitting portion of the waveguide with the coaxial outer conductor portion, and at a portion of the protective member fitted with the coaxial outer conductor portion. It is hard plated.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1. 1A and 1B show the first embodiment.
2A is a diagram showing a configuration of a coaxial waveguide converter 1 according to FIG.
The figure shows that the coaxial waveguide converter 1 has an output plug 28 of the traveling wave tube 20.
FIG. 2B is an exploded perspective view of a fitting portion of the coaxial waveguide converter 1 showing an example in which the coaxial waveguide converter 1 is joined to. The same applies to the case where the coaxial waveguide converter 1 is joined to the input plug 27 of the traveling wave tube 20, and therefore, in the following, when the coaxial waveguide converter 1 is joined to the output plug 28. Will be described only. In the figure, reference numeral 1 is a coaxial waveguide converter, in which the coaxial inner conductor 2 and one end 2a of the coaxial inner conductor 2 are joined, and a plate 7A as a protective member is fixed with a fixing screw 8
And the coaxial outer conductor 4 fitted to the plate 7A. An output plug 28 includes an outer conductor 28a, an inner conductor 28b, and a coaxial window 29 provided between the outer conductor 28a and the inner conductor 28b on the coaxial outer conductor 4 side of the output plug 28. There is. Here, as a material forming the coaxial waveguide converter 1, a portion (hereinafter, referred to as a portion excluding the protection member (plate 7A) of the waveguide 3)
An example in which a soft material such as aluminum or copper is used for the waveguide main body) and a spring metal such as beryllium copper, phosphor bronze, stainless steel, or Inconel is used for the coaxial outer conductor 4 is described. To do.

On the surface of the waveguide 3 opposite to the surface on which the one end 2a of the coaxial inner conductor 2 is joined, the coaxial inner conductor 2 is connected to the waveguide 3 as described above.
From the coaxial outer conductor 4 direction (the inner conductor 28b of the output connector 28)
A hole (hereinafter referred to as a hole of the waveguide main body) 9 for projecting to the side) is provided. On the coaxial outer conductor 4 side of the hole 9 of the waveguide main body, there is provided a square recess (hereinafter referred to as counterbore) 10 for accommodating the plate 7A. A female screw 10n for fixing the plate 7A to the waveguide main body is cut around the counterbore 10. The plate 7A is made of a material that is equivalent to or harder than the coaxial outer conductor 4, and has a through hole 7k having a diameter slightly smaller than the outer diameter of the fitting portion 5 of the coaxial outer conductor 4 at the center thereof. Is a square flat plate-shaped member having a through hole 7n for mounting the fixing screw 8 in the peripheral portion, and the outer shape thereof is a square equal to or slightly smaller than the counterbore 10. The through hole 7n is the counterbore 10. Is provided at a position corresponding to the female screw 10n provided on the peripheral portion of the. The hole diameter of the waveguide body 9 is smaller than the hole diameter of the through hole 7k of the plate 7A by the thickness of the fitting portion 5 of the coaxial outer conductor 4 and is coaxial with the waveguide 3. After assembling the outer conductor 4, the inner diameter of the portion of the plate 7A corresponding to the coaxial outer conductor 4 is set to be kept constant.

Before fitting the coaxial outer conductor 4 and the waveguide 3 to each other, the plate 7A as a protection member is attached to the waveguide 3. First, the plate 7A is put into the counterbore 10 of the waveguide 3, and the plate 7A is tightly fixed to the waveguide 3 by the fixing screw 8. Next, by fitting the fitting portion 5 of the coaxial outer conductor 4 into the through hole 7k of the plate 7A, the coaxial outer conductor 4 and the waveguide 3 are fitted together. At this time, the fitting portion 5 of the coaxial outer conductor 4 is not in direct contact with the waveguide body,
Since it is in contact only with the through hole 7k of the plate 7A made of a material equal to or harder than the coaxial outer conductor 4,
When the waveguide 3 and the coaxial outer conductor 4 are connected to each other, the waveguide 3 is less likely to be scraped off, and it is possible to reduce the falling off of metal pieces and the like during the fitting, and the traveling wave tube 20 (see FIG. 8) The stability can be improved. Also, the through hole 7k of the plate 7A
Since the inner diameter of the coaxial outer conductor 4 is set to be larger than the diameter of the hole 9 of the waveguide main body by the thickness of the fitting portion 5 of the coaxial outer conductor 4, the inner diameter of the coaxial outer conductor 4 and the hole of the coaxial inner conductor 2 are set. It is possible to join the coaxial outer conductor 4 and the waveguide 3 in a state where 9 is matched,
It is possible to prevent the mismatch of the characteristic impedance of the coaxial line.

Embodiment 2. In the first embodiment, the counterbore 10 is provided on the waveguide 3 and the plate 7 serving as a protection member is provided.
Although A is fixed, as shown in FIGS. 2 (a) and 2 (b), the fitting portion of the waveguide 3 is stepped, and the stepped portion 3p is equal to or harder than the coaxial outer conductor 4. The same effect can be obtained by closely fixing the plate 7B, which is a protective member made of a material. As shown in FIG. 2B, the plate 7B is a rectangular flat plate corresponding to the concave portion (stepped portion 3p) of the waveguide 3 forming the stepped portion 3p, and the diameter of the plate 7B is at the center thereof as described above. The coaxial outer conductor 4 has a through hole 7p having a diameter slightly smaller than the outer diameter of the fitting portion 5, and a through hole 7m for mounting a fixing screw 8 (not shown) in the peripheral portion. Also,
A female screw 1 for fixing the plate 7B to the waveguide body is provided at a position of the stepped portion 3p corresponding to the through hole 7m.
0n is cut off. The relationship between the through hole 7p and the hole 9 of the waveguide body and the fitting portion 5 of the coaxial outer conductor 4 is the same as that in the first embodiment. Also in the second embodiment, after the plate 7B is closely fixed to the waveguide 3, the coaxial outer conductor 4 and the waveguide 3 are joined by fitting with the coaxial outer conductor 4.

Embodiment 3. In the first and second embodiments, the plate 7A or the plate 7B is tightly fixed to the waveguide 3 by using the fixing screw 8. However, as shown in FIG.
The same effect can be obtained by brazing using the brazing material 12.

Fourth Embodiment First, Second, Third Embodiment
Then, the hole 9 of the waveguide main body is provided in advance, and the through holes 7k and 7p for fitting with the coaxial outer conductor 4 are provided in the plate 7A or the plate 7B. However, as shown in FIG. After the plate-shaped plate 7 having a simple structure having no through hole is closely fixed to the waveguide main body, as shown in FIG.
As shown in (b), the hole 9 in the waveguide body and the through hole 7
Through holes 7q similar to k and 7p may be simultaneously processed to form a protective member. If the coaxial inner conductor 2 is attached to the processed waveguide 3 and then fitted with the coaxial outer conductor 4,
It is possible to obtain the same effects as those of the first and second embodiments.

Embodiment 5. In the first to fourth embodiments, the plate (7A, 7B, 7) is used as the protection member, but as shown in FIG. 5, the through hole made of a material equal to or harder than the coaxial outer conductor 4 is used. The same effect can be obtained by press-fitting the eyelet 13 having the same through hole 13k as 7k and 7p into the waveguide 3. In addition, a stepped counterbore 14 for inserting the eyelet 13 is provided in the waveguide body, and after the eyelet 13 is press-fitted into the waveguide 3, the waveguide 3 and the coaxial outer conductor 4 are fitted together. To do. In place of the eyelet 13, a protective member having a cylindrical or polygonal columnar outer shape having through holes similar to the through holes 7k and 7p made of a material equal to or harder than the coaxial outer conductor 4 is used. Is also good. At this time, it goes without saying that the waveguide body is provided with a counterbore for inserting the protective member. If the outer peripheral side surface of the protective member is knurled, the waveguide 3 and the protective member can be more firmly adhered and fixed.

Sixth Embodiment In the sixth embodiment, instead of using the plate (7A, 7B, 7) or the eyelet 13, as shown in FIG.
A cylindrical hollow screw 15 having a through hole 15k similar to that of k or the like and having a mounting screw 15n on its side surface is provided in advance on the inner circumference of the waveguide 3 on the coaxial outer conductor 4 side. The same effect can be obtained even if the protective member is formed by arranging it in a hollow cylindrical recess (counterbore) 16 corresponding to the screw of the hollow screw 15.

Embodiment 7. The seventh embodiment is shown in FIG.
As shown in (a), the fitting hole 17 of the waveguide 3 and the fitting portion 5 of the coaxial outer conductor 4 are tapered to fit the coaxial outer conductor 4 to the waveguide 3. Is. At the time of fitting, the tapered portion serves as a sliding surface, and both can be connected without scraping the waveguide 3. In addition, the taper difference between the fitting hole 17 of the waveguide 3 and the fitting portion 5 of the coaxial outer conductor 4 is reduced to reduce the waveguide 3
When the contact pressure with the coaxial outer conductor 4 is reduced, for example, as shown in FIG. 7B, a support structure 18 that encloses the coaxial outer conductor 4 (in the figure, a rectangular parallelepiped casing ) Is provided and the support structure 18 is screwed to the waveguide main body, the fitting can be made more reliable.

Embodiment 8. In the first to sixth embodiments, the plate (7A, 7B, 7) or the eyelet 1 is used.
3, a material made of a material equal to or harder than the coaxial outer conductor 4 is attached to the waveguide main body as a protective member for the hollow screw 15, but the coaxial outer conductor 4 is fitted to the waveguide 3. The same effect can be obtained even if the portion (the portion corresponding to the inner peripheral surface 6k of the waveguide hole 6 shown in FIG. 9) or the entire waveguide 3 is preliminarily subjected to hard plating such as hard gold plating. The hard plating has the effect of making the fitting portion on the waveguide side hard and reducing the skin resistance,
The coaxial characteristic can be improved. Alternatively, the plate (7A, 7B, 7) or the protective member such as the eyelet 13 and the hollow screw 15 may be hard-plated in advance such as hard gold plating, and then tightly fixed to the waveguide 3. In addition, the above-mentioned hard plating is applied to the plates (7A, 7B,
7) Alternatively, the eyelet 13 and the hollow screw 15 are attached to the waveguide 3
It may be performed after closely fixing to. In these cases, since these protections can be exchanged, when the coaxial outer conductor portion 4 is attached to or detached from the waveguide 3, in the event that there is a problem such as damage to the fitting portion, the above protection is performed. The members can be replaced.

[0028]

As described above, according to the invention described in claim 1, the fitting portion of the waveguide with the coaxial outer conductor portion is made of a material which is equal to or harder than the coaxial outer conductor portion. Since the surface of the waveguide fitting portion is a hard surface equal to or more than the surface of the coaxial outer conductor fitting portion, the surfaces of both fitting portions are less likely to be scraped. as a result,
It is possible to reduce the falling of metal pieces to the ceramic window,
Problems caused by high-frequency discharge or the like induced by the dropping of the metal piece can be reduced.

According to the second aspect of the present invention, the hole diameter of the fitting portion on the side of the waveguide body is made smaller than the hole diameter of the protective member in consideration of the wall thickness of the coaxial outer conductor fitting portion. I did so,
Even after assembling the waveguide and the coaxial outer conductor, the inner diameter of the portion of the protective member corresponding to the coaxial outer conductor can be kept constant,
The characteristics of the coaxial portion can be stabilized. Further, the mismatch of the characteristic impedance can be prevented, and the traveling wave tube can be stably operated.

According to the third aspect of the present invention, since the protective member is plate-shaped and screwed to the waveguide, the waveguide fitting portion is equivalent to or more than the coaxial outer conductor portion with a simple structure. It can be a hard surface.

According to the fourth aspect of the present invention, since the protective member is brazed to the waveguide, the protective member can be easily attached to the waveguide.

According to the fifth aspect of the present invention, since the protective member is formed by closely fixing the hard material to the waveguide and forming a hole on the waveguide body side at the same time, the protective member is formed. The shape can be simplified.

According to the sixth aspect of the invention, the protection member is press-fitted into the waveguide, so that the protection member can be easily attached.

According to the seventh aspect of the invention, since the protective member has a hollow screw structure and is screwed to the waveguide, the protective member can be easily and surely attached.

According to the invention described in claim 8, since the hole of the fitting portion has a taper structure, the fitting can be smoothly carried out and a reliable contact state can be realized.

According to the invention described in claim 9, since the fitting portion of the coaxial outer conductor portion has a tapered shape, the fitting can be smoothly can be realized reliably contact.

According to the tenth aspect of the invention, since the fitting portion of the waveguide with the coaxial outer conductor portion is hard-plated,
Not only the surface of the fitting portion is less likely to be scraped, but also the skin resistance can be reduced, and the characteristics of the coaxial waveguide converter can be improved.

According to the eleventh aspect of the present invention, since the fitting member for fitting the coaxial outer conductor portion of the waveguide is provided with the protective member preliminarily hard-plated, the waveguide fitting portion is not coaxial. Not only can the surface of the conductor be the same as or harder than that of the conductor, but the protective member can be replaced if the fitting is damaged.

According to the twelfth aspect of the present invention, the protective member is provided at the fitting portion of the waveguide with the coaxial outer conductor portion, and the portion of the protective member fitted with the coaxial outer conductor portion is hard plated. As a result, the surface of the fitting portion can be prevented from being scraped and the protection member can be replaced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a coaxial waveguide converter according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a coaxial waveguide converter according to a second embodiment.

FIG. 3 is a diagram showing a coaxial waveguide converter according to a third embodiment.

FIG. 4 is a diagram showing a coaxial waveguide converter according to a fourth embodiment.

FIG. 5 is a diagram showing a coaxial waveguide converter according to a fifth embodiment.

FIG. 6 is a diagram showing a coaxial waveguide converter according to a sixth embodiment.

FIG. 7 is a diagram showing a coaxial waveguide converter according to a seventh embodiment.

FIG. 8 is a vertical cross-sectional view showing a schematic configuration of a conventional traveling wave tube.

FIG. 9 is a diagram showing a configuration of a conventional coaxial waveguide converter.

FIG. 10 is a diagram showing another configuration of a conventional coaxial outer conductor.

[Explanation of symbols]

1 coaxial waveguide converter, 2 coaxial inner conductor, 3 waveguide,
4 coaxial outer conductor, 5 fitting portion of coaxial outer conductor, 6 waveguide hole, 6k inner peripheral surface of waveguide hole, 7A, 7B plate,
7 (no through hole) plate, 7k, 7p, 7q, 1
3k, 15k through hole, 8 fixing screw, 9 waveguide body hole, 10 square countersink, 12 brazing filler metal, 13 eyelet, 14 stepped counterbore, 15 hollow screw, 1
6 cylindrical counterbore, 17 waveguide fitting hole, 18 support structure, 28 output plug, 28a output plug outer conductor, 28b output plug inner conductor, 29 ceramic window.

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Claims (12)

(57) [Claims] 1. A coaxial waveguide converter formed by fitting a coaxial outer conductor portion and a waveguide having a part of the coaxial portion, in a fitting portion of the waveguide with the coaxial outer conductor portion, A coaxial waveguide converter comprising a protective member made of a material that is the same as or harder than the coaxial outer conductor portion. 2. The coaxial waveguide converter according to claim 1, wherein the hole diameter of the fitting portion of the waveguide is smaller than the hole diameter of the protection member. 3. The coaxial waveguide converter according to claim 1, wherein the protective member has a plate shape and is screwed to the waveguide body. 4. The coaxial waveguide converter according to claim 1, wherein the protective member is brazed to the waveguide. 5. The protective member is formed by closely fixing a hard material to the waveguide and punching the same at the same time as the hole of the fitting portion of the waveguide. Coaxial waveguide converter. 6. The coaxial waveguide converter according to claim 1, wherein the protective member is press-fitted into the waveguide. 7. The coaxial waveguide converter according to claim 1, wherein the protective member has a hollow screw structure and is screwed to the waveguide. 8. The coaxial waveguide converter according to claim 1, wherein the hole of the fitting portion of the waveguide has a tapered structure. 9. The coaxial waveguide converter according to claim 1, wherein the fitting portion of the coaxial outer conductor portion has a tapered shape. 10. A coaxial waveguide converter formed by fitting a coaxial outer conductor portion and a waveguide having a part of the coaxial portion, wherein the fitting portion of the waveguide with the coaxial outer conductor portion is hard. A coaxial waveguide converter characterized by being plated. 11. A coaxial waveguide converter formed by fitting a coaxial outer conductor part and a waveguide having a part of the coaxial part, wherein the fitting part of the waveguide with the coaxial outer conductor part is previously formed. A coaxial waveguide converter characterized by comprising a hard-plated protective member. 12. A coaxial waveguide converter formed by fitting a coaxial outer conductor part and a waveguide having a part of the coaxial part, and protecting the fitting part of the waveguide with the coaxial outer conductor part. A coaxial waveguide converter characterized in that a member is provided and that a portion of the protective member that fits with the coaxial outer conductor portion is plated with hard metal.