JP5770508B2 - Waveguide converter - Google Patents

Description

  The present invention relates to a waveguide converter that converts a waveguide mode of radio waves.

Conventionally, in order to cope with various transmission formats of radio waves, radio waves are transmitted between waveguides having different wave guide modes.
For example, the waveguide converter described in Patent Document 1 includes a waveguide (waveguide body) and a coaxial connector (second waveguide) provided on a side surface of the waveguide. Yes.

  A ridge (impedance adjusting member) is provided on the inner peripheral surface of the waveguide so as to protrude from the inner peripheral surface, and the tip of the ridge in the protruding direction is connected to the central conductor of the coaxial connector. A plurality of steps are formed in the ridge, and the impedance is gradually converted in the longitudinal direction of the waveguide by the plurality of steps. Further, counterbore portions recessed from the inner peripheral surface are provided on both side portions of the base end portion of the ridge on the inner peripheral surface of the waveguide. By providing a counterbore, the equivalent ridge height for the TE20 mode can be changed so that the cutoff frequency of the TE20 mode for each step does not enter the vicinity of the use (transmission signal) frequency.

The ridge waveguide (waveguide converter) described in Patent Document 2 is provided on a pyramid horn (waveguide body) having a pair of ridges on the inner surface and on the outer peripheral surface of the pyramid horn. And a coaxial connector (second waveguide). The pair of ridges are arranged so as to face each other with a certain distance therebetween. One ridge is formed in a mountain shape, and the other ridge is formed in a valley shape corresponding to the mountain shape.
By configuring the ridge waveguide in this way, impedance matching can be achieved without deteriorating electrical performance.

Japanese Patent No. 3508040 Japanese Patent No. 3379430

  However, in the waveguide converters described in Patent Documents 1 and 2, when a radio wave having a relatively large output is transmitted, a spark is generally generated between the waveguide main body and the ridge that have the weakest power durability. Thus, there is a problem that transmission of radio waves is hindered. When a rectangular waveguide is used as the waveguide main body, the size of the waveguide main body depends on the size of the second waveguide, so that it is difficult to take measures between the waveguide main body and the ridge. .

  The present invention has been made in view of such problems, and an object of the present invention is to provide a waveguide converter with improved power resistance between the waveguide body and the ridge.

In order to solve the above problems, the present invention proposes the following means.
The waveguide converter of the present invention includes a first waveguide section and a second waveguide section coaxial with the first waveguide section, and the first waveguide section and the second waveguide section. A waveguide converter for transmitting radio waves between the first waveguide section and a waveguide body formed in a cylindrical shape, and provided on an inner peripheral surface of the waveguide body. An impedance adjusting member protruding inward of the waveguide body, and the second waveguide portion is formed in a cylindrical shape, and is connected to the waveguide body, and the external conductor A center conductor disposed on the same axis as the conductor and connected to the tip of the impedance adjustment member in the protruding direction, and on the inner peripheral surface of the waveguide body with respect to the tip of the impedance adjustment member The portion on the protruding direction side has a tip of the impedance adjusting member when viewed in parallel with the axis of the outer conductor. Inner than the distance to the circumferential surface, the retracting section is of formed spaced from the distal end of said impedance adjusting member in the projecting direction of the outer conductor located on the protruding direction with respect to the distal end of the impedance adjusting member from Part In the connecting portion between the waveguide main body and the outer conductor, a recess is formed in a portion on the protruding direction side with respect to the distal end portion of the impedance adjusting member when viewed in parallel to the central axis of the outer conductor. The concave portion has an inclined surface that is separated from the tip end portion of the impedance adjusting member in the projecting direction as it approaches the tip end portion of the impedance adjusting member in the axial direction of the outer conductor .

In the above-described waveguide converter, it is more preferable that the retracting portion is formed over the entire range in which the impedance adjusting member is provided in the axial direction of the outer conductor .

In the above-described waveguide converter, the tip of the impedance adjusting member is disposed on the central axis of the outer conductor, and when viewed parallel to the central axis of the outer conductor, the surface of the retracting portion Is more preferably formed so as to be coaxial with the inner peripheral surface of the outer conductor .

  In the above-mentioned waveguide converter, the lid includes a lid that is detachably connected to an end of the waveguide body opposite to the side to which the outer conductor is connected. A communication hole that penetrates in the thickness direction of the lid portion and communicates the conduit of the waveguide main body and the external space is formed, and when viewed in parallel with the thickness direction, the communication hole has a rectangular shape. More preferably, it is formed.

  According to the waveguide converter of the present invention, the power durability between the waveguide body and the ridge can be improved.

It is sectional drawing of the side surface in the waveguide converter of one Embodiment of this invention. It is the front view which fractured | ruptured a part of the waveguide converter by cutting line A1-A1 in FIG. It is sectional drawing of the principal part in the waveguide converter of the modification of one Embodiment of this invention. It is sectional drawing of the principal part in the waveguide converter of the modification of one Embodiment of this invention. It is a partial cross section figure of the principal part in the waveguide converter of the modification of one Embodiment of this invention. It is sectional drawing of the side surface in the waveguide converter of a comparative example. It is the front view which fractured | ruptured a part of same waveguide converter by cutting line A2-A2 in FIG.

Hereinafter, an embodiment of a waveguide converter according to the present invention will be described with reference to FIGS. This waveguide converter is configured so that a waveguide can be connected to both ends, and one side of itself can be rotated around a predetermined axis.
As shown in FIG. 1, the waveguide converter 1 of the present embodiment includes a first waveguide section 10, a second waveguide section 30 of a coaxial line, and a third waveguide section 50. The end portions of the first waveguide portion 10 and the second waveguide portion 30 are connected to each other, and the end portions of the second waveguide portion 30 and the third waveguide portion 50 are connected to each other. Prepared in state.

As shown in FIG. 1 and FIG. 2, the first waveguide portion 10 is provided on a cylindrical waveguide body 12 and an inner peripheral surface 12 a of the waveguide body 12. 12 and a ridge (impedance adjusting member) 13 projecting inwardly.
The waveguide body 12 is formed so as to extend in the extending direction X. A retracting portion 14 is formed on the inner peripheral surface 12a of the waveguide body 12 at a portion further on the protruding direction Y1 side of the distal end portion 13c of the ridge 13 in the protruding direction Y1. The shape of the retracting portion 14 will be described later.
The portion of the inner peripheral surface 12a of the waveguide body 12 where the ridge 13 is provided is formed in a flat shape perpendicular to the protruding direction Y1.

A flange 15 is provided on the outer peripheral surface of the waveguide body 12 opposite to the side to which the second waveguide portion 30 is connected, that is, the one side X1 in the extending direction X. A plurality of through holes 16 penetrating in the plate thickness direction of the flange 15 are formed around the axis C <b> 1 of the waveguide body 12 on the outer peripheral surface side of the flange 15. The flange 15 and the plurality of through holes 16 are used when another waveguide is connected to the first waveguide portion 10.
A mounting groove 17 for mounting the O-ring is formed on the side of the axis C1 with respect to the through hole 16 on the surface X1 of the flange 15. A choke groove 18 is formed on the side of the axis C <b> 1 with respect to the mounting groove 17 on the surface X <b> 1 side of the flange 15. The mounting groove 17 and the choke groove 18 are formed around the entire circumference of the axis C1.
A plurality of positioning holes 12b are formed on the outer surface of the waveguide of the waveguide body 12 at the end face on one side X1 of the waveguide body 12.
At the end of one side X1 of the inner peripheral surface 12a of the waveguide main body 12, there is a recess 20 for matching the shape when viewed in parallel with the extending direction X to a communication hole 23a of the lid portion 23 described later. Is formed.

A lid portion 23 is detachably connected to the end face on one side X1 of the waveguide body 12 by soldering or the like so as to cover the pipe line of the waveguide body 12.
The lid portion 23 is formed with a communication hole 23 a that penetrates in the thickness direction (extending direction X) of the lid portion 23 and communicates the conduit of the waveguide body 12 and the external space. When viewed parallel to the extending direction X, the communication hole 23a is formed in a rectangular shape (see FIG. 2).
A plurality of positioning holes 23b corresponding to the positioning holes 12b of the waveguide body 12 are formed on the surface of the lid portion 23 on the other side X2 opposite to the one side X1. When attaching the lid portion 23 to the waveguide body 12, the lid portion 23 can be positioned with respect to the waveguide body 12 by inserting both end portions of a positioning pin (not shown) into the positioning holes 12b and 23b, respectively. it can.
When the lid portion 23 is attached to the waveguide body 12, the surface on the one side X1 of the lid portion 23 is stepped so as to be located slightly on the other side X2 than the surface on the one side X1 of the flange 15. Yes.
The stepped structure of the choke groove 18 and the flange 15 and the lid 23 described above can reduce radio waves leaking from between the flange 15 and another waveguide connected to the flange 15.

The ridge 13 is formed with a plurality of steps 13a and 13b so as to protrude in the protruding direction Y1 toward the other side X2. The tip end portion 13c in the protruding direction Y1 from which the ridge 13 protrudes is disposed on the central axis C2 of the second waveguide portion 30. The tip portion 13c of the ridge 13 is set so as not to contact the inner peripheral surface 12a of the waveguide body 12. The shape of the ridge 13 is set so that the impedances of the first waveguide portion 10 and the second waveguide portion 30 are substantially equal.
The waveguide main body 12, the ridge 13 and the lid portion 23 are made of a metal such as aluminum. The ridge 13 is connected to the inner peripheral surface 12a of the waveguide main body 12 by soldering or screw joining.

The second waveguide section 30 has an outer conductor 32 formed in a cylindrical shape, and a center conductor 33 disposed coaxially with the outer conductor 32.
The outer conductor 32 is connected to the waveguide body 12 so that the axis C1 of the waveguide body 12 and its center axis (corresponding to the center axis C2) are parallel. In this example, the outer conductor 32 and the waveguide body 12 are integrally formed.
Here, as viewed in parallel with the extending direction X as shown in FIG. 2, the inner peripheral surface 32a of the outer conductor 32 positioned in the protruding direction Y1 from the tip portion 13c of the ridge 13 with respect to the tip portion 13c. The distance to is L1. The aforementioned retracting portion 14 of the waveguide body 12 is separated from the distal end portion 13c by a distance L1 in the protruding direction Y1. Further, the surface of the retracting portion 14 is formed to be coaxial with the inner peripheral surface 32 a of the outer conductor 32.
In addition, it is preferable that the length of the extending direction X of the retracting portion 14 is set to be sufficiently long.
As shown in FIG. 1, two bearing units 35 and 36 are attached to the outer peripheral surface of the outer conductor 32 side by side in the extending direction X. Further, two oil seals 37 and 38 are attached to the outer peripheral surface of the outer conductor 32 so as to sandwich the bearing units 35 and 36 in the extending direction X.

The center conductor 33 has a center conductor 40 disposed in the center portion of the center conductor 33 in the extending direction X, and end conductors 41 and 42 connected to one side X1 and the other side X2 of the center conductor 40, respectively. doing. The central conductor 40 and the end conductors 41 and 42 are each formed in a rod shape and are disposed on the central axis C2.
Engagement portions 40a and 40b projecting in the extending direction X are provided at the central portions of the end faces of the one side X1 and the other side X2 of the central conductor 40, respectively.
At the edge of the end surface on the other side X2 of the end conductor 41, an engaged portion 41a protruding to the other side X2 is provided. Between the engaging portion 40a of the center conductor 40 and the engaged portion 41a of the end conductor 41, for example, a ring-shaped connecting member 43 made of polytetrafluoroethylene is disposed. The end face on one side X1 of the end conductor 41 is connected to the tip end portion 13c of the ridge 13 by soldering or the like.
Similarly, an engaged portion 42a protruding to the one side X1 is provided at the edge of the end surface on the one side X1 of the end conductor 42. Between the engaging portion 40b of the central conductor 40 and the engaged portion 42a of the end conductor 42, a ring-shaped connecting member 44 made of the same material as the connecting member 43 is disposed. The thus configured central conductor 40 can rotate about the central axis C2 with respect to the end conductor 41, and the end conductor 42 rotates about the central axis C2 with respect to the central conductor 40. Can move.

  The outer conductor 32, the central conductor 40, and the end conductors 41 and 42 are formed of the same material as the waveguide body 12.

The third waveguide portion 50 includes a waveguide main body 52 formed in a cylindrical shape, a ridge 53 provided on the inner peripheral surface 52a of the waveguide main body 52 and protruding in the protruding direction Y1, and a waveguide main body. 52 and an outer cylinder member 54 formed in a cylindrical shape.
The waveguide main body 52 is formed so as to extend in the extending direction X as well as the above-described waveguide main body 12, and is formed with a recess 56, a recess 57, and a plurality of positioning holes 52b.
A flange 58 is provided on the outer peripheral surface of the other side X2 of the waveguide main body 52. On the outer peripheral surface side of the flange 58, a plurality of through holes 59 that penetrates in the plate thickness direction of the flange 58 are formed around the central axis C2.
The leading end 53a of the ridge 53 in the protruding direction Y1 is connected to the end face of the other end X2 of the end conductor 42 by soldering or the like.

A lid portion 61 configured in the same manner as the lid portion 23 is detachably connected to the end surface of the other side X2 of the waveguide main body 52. The lid portion 61 is formed with a communication hole 61a and a plurality of positioning holes 61b. When attaching the lid portion 61 to the waveguide main body 52, it can be positioned in the same manner as the lid portion 23 described above.
The inner peripheral surface of the outer cylinder member 54 is attached to the outer peripheral surfaces of the bearing units 35 and 36 and the oil seals 37 and 38.

The waveguide body 52 and the outer cylinder member 54 are integrally formed. The waveguide body 52, the ridge 53, the outer cylinder member 54, and the lid portion 61 are made of the same material as the waveguide body 12.
The waveguide body 52 configured in this way is connected to the external conductor 32 by the bearing units 35 and 36 in a state where the connection portion between the waveguide body 52 and the external conductor 32 is kept airtight by the oil seals 37 and 38. On the other hand, it can rotate around the central axis C2.

  Next, the operation of the waveguide converter 1 configured as described above will be described. Hereinafter, a first rectangular waveguide and a second rectangular waveguide are connected to the flange 15 of the first waveguide portion 10 and the flange 58 of the third waveguide portion 50, respectively. It is assumed that radio waves are transmitted from the rectangular waveguide. When the waveguide converter 1 is used, it is preferable to enclose dry air pressurized to about several atmospheres in the waveguide body 12, the outer conductor 32, and the waveguide body 52.

The radio wave transmitted from the first rectangular waveguide is transmitted to the first waveguide portion 10 through the communication hole 23 a of the lid portion 23. The radio wave is converted from the waveguide mode to the coaxial mode by the ridge 13 whose impedance is adjusted as described above, and transmitted to the second waveguide unit 30. At this time, an electric field stronger than the surrounding portion is generated between the tip portion 13c of the ridge 13 and the retracting portion 14 of the waveguide body 12.
The integrally formed waveguide body 52 and outer cylinder member 54 rotate around the central axis C2 with respect to the integrally formed outer conductor 32 and waveguide body 12, and the outer conductor 32 and the center conductor. 33 is formed to be rotationally symmetric with respect to the central axis C2. For this reason, the radio wave is transmitted through the second waveguide portion 30 regardless of the orientation of the second rectangular waveguide with respect to the first rectangular waveguide, and is further transmitted from the second waveguide portion 30 to the first waveguide. The signal is converted from the coaxial mode to the waveguide mode and transmitted to the three waveguide portions 50. In addition, since the 2nd waveguide part 30 is formed so that it may become rotationally symmetric with respect to the center axis line C2, its withstand power is large.
The radio wave transmitted in the waveguide mode in the third waveguide unit 50 is transmitted to the second rectangular waveguide through the communication hole 61 a of the lid unit 61.
As described above, the waveguide converter 1 can output the radio wave input in the waveguide mode in the waveguide mode rotated at an arbitrary angle around the central axis C2.

  As described above, according to the waveguide converter 1 of the present embodiment, the radio wave is guided from the first waveguide section 10 in the waveguide mode to the second waveguide section 30 in the coaxial mode. When the mode is changed, the waveguide body 12 of the first waveguide portion 10 is separated from the distal end portion 13c by the distance L1 in the protruding direction Y1 when viewed in parallel with the extending direction X. A retracting portion 14 is formed. For this reason, it can suppress that a spark (spark) generate | occur | produces between the front-end | tip part 13c of the ridge 13, and the retracting part 14 of the waveguide main body 12, and can improve the power durability of the waveguide converter 1. FIG. .

The tip 13c of the ridge 13 is disposed on the central axis C2 of the outer conductor 32, and the surface of the retracting portion 14 is coaxial with the inner peripheral surface 32a of the outer conductor 32 when viewed in parallel with the extending direction X. It is formed to become. For this reason, the distance from the front-end | tip part 13c to the surface of the retracting part 14 becomes substantially equal, and it can suppress effectively that a spark generate | occur | produces between the front-end | tip part 13c and the retracting part 14. FIG.
The first waveguide portion 10 includes a lid portion 23 in which a communication hole 23a is formed. Therefore, the first waveguide portion 10 can be easily connected to other rectangular waveguides while suppressing the return loss from deteriorating.

Since the retracting portion 14 of the waveguide body 12 is formed so as to be coaxial with the inner peripheral surface 32a, the retracting portion 14 can be easily processed with a milling machine or the like.
By setting the length of the retracting portion 14 in the extending direction X to be sufficiently long, it is possible to prevent radio waves from being reflected at the first waveguide portion 10 and to reduce return loss.
By enclosing the pressurized dry air in the waveguide body 12, the outer conductor 32, and the waveguide body 52, the power durability of the waveguide converter 1 can be improved.

In the present embodiment, as shown in FIG. 3, a recess 71 may be formed in the connection portion between the waveguide body 12 and the external conductor 32.
In this modification, the recess 71 is formed in a portion on the side of the protrusion direction Y1 with respect to the tip portion 13c of the ridge 13 when viewed in parallel to the extending direction X. The surface of the recess 71 is formed in a taper shape that is separated from the tip portion 13c in the protruding direction Y1 as it approaches the tip portion 13c in the extending direction X.
By forming the recess 71, the power durability of the waveguide converter 1 can be further improved.

In the present embodiment, the ridge 81 may be configured as shown in FIG. In this modification, the end portion on the one side X1 side of the ridge 81 is attached to the waveguide body 12 by a screw member 82. The ridge 81 projects from the inner peripheral surface 12 a of the waveguide body 12 in the projecting direction Y 1, further curves to the other side X 2, and the end of the other side X 2 is connected to the end conductor 41. The ridge 81 can be formed by, for example, bending a metal rod-shaped member. The ridge 81 and the end conductor 41 may be integrally formed.
By configuring the ridge 81 in this way, the manufacturing cost of the waveguide converter 1 can be reduced.

As mentioned above, although one Embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this Embodiment, The change of the structure of the range which does not deviate from the summary of this invention is included. .
For example, in the above embodiment, the surface of the retracting portion 14 is formed in a curved shape so as to be coaxial with the inner peripheral surface 32 a of the outer conductor 32. However, the surface of the retracting part may be formed flat like the surface of the retracting part 85 shown in FIG.

In the above-described embodiment, the waveguide body 12, the ridge 13, the lid portion 23, and the like are formed of aluminum, but these can also be formed of a metal such as brass.
When the return loss of the waveguide converter 1 does not matter much, the waveguide converter 1 may not be provided with the lid portion 23.
In the above-described embodiment, in the case where the waveguide mode of radio waves is only converted between the waveguide mode and the coaxial mode, the waveguide converter 1 is not provided with the third waveguide portion 50. Also good.
In the said embodiment, although the waveguide main body 12 was cylindrical, the shape of a waveguide main body is not restricted to this. For example, the waveguide main body may be formed in a so-called rectangular tube shape having a rectangular cross section by a plane orthogonal to the axis C1.

(Example)
The result of having simulated the power durability of the waveguide converter 1 of this embodiment is demonstrated. The simulation used a frequency of 10 GHz for the X band and 5 GHz for the C band. The input of radio waves was 1W.
As a comparative example, the same test as the waveguide converter 1 was performed on the waveguide converter W shown in FIGS. In the waveguide converter W of this comparative example, the retracting portion 14 is not formed in the waveguide body 12, and the protruding direction Y1 side of the tip portion 13 c of the ridge 13 on the inner peripheral surface 12 a of the waveguide body 12. The flat part W1 is formed in this part. The flat portion W1 has the above-described distance L1 from the tip portion 13c in the protruding direction Y1.
In the waveguide converter 1 of the embodiment and the waveguide converter W of the comparative example, specifications of the waveguide connected to the lid portion 23 side will be described. As shown in FIGS. 2 and 7, when the radio wave was in the X band, a rectangular waveguide having a dimension a of 22.9 mm and a dimension b of 10.2 mm was connected. When the radio wave was in the C band, a rectangular waveguide having a dimension a of 47.55 mm and a dimension b of 22.15 mm was connected.

In the case of the waveguide converter 1 of the present embodiment, the electric field strength at the tip 13c of the ridge 13 is 10,470 V / m in the X band and 5,190 V / m in the C band. On the other hand, in the case of the waveguide converter W of the comparative example, the electric field strength at the tip 13c of the ridge 13 was 13,900 V / m in the X band and 6,300 V / m in the C band.
As described above, by providing the retracting portion 14 as in the waveguide converter 1 of this embodiment with respect to the waveguide converter W of the comparative example, the electric field strength is reduced by about 20%, and the waveguide is reduced. It was found that the power durability of the tube converter 1 is improved.

DESCRIPTION OF SYMBOLS 1 Waveguide converter 10 1st waveguide part 12 Waveguide main body 12a Inner peripheral surface 13 Ridge (impedance adjustment member)
13c Front end portion 14, 85 Retraction portion 23 Lid portion 23a Communication hole 30 Second waveguide portion 32 External conductor 32a Inner peripheral surface 33 Center conductor 71 Recess C1 Axis C2 Center axis Y1 Projection direction

Claims (4)

A waveguide converter comprising a first waveguide section and a coaxial second waveguide section, and transmitting radio waves between the first waveguide section and the second waveguide section. A vessel,
The first waveguide section is
A waveguide body formed in a cylindrical shape;
An impedance adjusting member provided on an inner peripheral surface of the waveguide body and protruding inward of the waveguide body;
Have
The second waveguide section is
An outer conductor formed in a cylindrical shape and connected to the waveguide body;
A central conductor disposed coaxially with the outer conductor and connected to a tip of the impedance adjusting member in a protruding direction;
Have
A portion of the inner peripheral surface of the waveguide body on the protruding direction side with respect to the tip of the impedance adjusting member is projected from the tip of the impedance adjusting member when viewed in parallel to the axis of the outer conductor. A retracting portion is formed that is separated from the front end portion of the impedance adjusting member in the projecting direction than the distance to the inner peripheral surface of the outer conductor located in the projecting direction with respect to the front end portion of the adjusting member ,
In the connection portion between the waveguide main body and the outer conductor, a concave portion is formed in a portion on the protruding direction side with respect to the distal end portion of the impedance adjusting member when viewed in parallel to the central axis of the outer conductor,
The waveguide converter, wherein the concave portion has an inclined surface that is separated from the tip end portion of the impedance adjusting member in the projecting direction as it approaches the tip end portion of the impedance adjusting member in the axial direction of the outer conductor . . 2. The waveguide converter according to claim 1, wherein the retracting portion is formed over an entire range in which the impedance adjusting member is provided in an axial direction of the outer conductor. The tip of the impedance adjusting member is disposed on the central axis of the outer conductor,
2. The waveguide according to claim 1, wherein when viewed parallel to a central axis of the outer conductor, the surface of the retracting portion is formed to be coaxial with an inner peripheral surface of the outer conductor. Tube converter. A lid portion detachably connected to an end of the waveguide body opposite to the side to which the outer conductor is connected;
The lid portion is formed with a communication hole that penetrates in the thickness direction of the lid portion and communicates the conduit of the waveguide body and the external space,
The waveguide converter according to any one of claims 1 to 3, wherein the communication hole is formed in a rectangular shape when viewed in parallel with the thickness direction.

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