JP2022160818A - choke structure - Google Patents

Abstract

To realize a structure that ensures good isolation in a waveguide two-channel rotary joint, and to solve problems that occur with the structure.SOLUTION: A choke device includes a first choke portion 31 provided on the side of a communicating portion between a fourth waveguide 13 and a hollow hole 112 of a fixed body 11 into which a coaxial waveguide 23 of a rotary waveguide portion is inserted, a second choke portion 32 provided on the side of a communicating portion between the hollow hole 112 of the fixed body 11 and a third waveguide 12, a partition member 33 interposed between the first choke portion 31 and the second choke portion 32 and provided with an inner tube through hole 331 through which an inner tube 231 of the coaxial waveguide 23 passes, and a bearing member 34 that is accommodated inside the second choke portion 32 and supports the inner tube 231 of the coaxial waveguide 23 so as to be axially rotatable, and around the inner tube through hole 331 of the partition member 33, a liquid drain through hole 332 that allows the first choke portion 31 and the second choke portion 32 to communicate with each other is provided.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a choke structure, and more particularly to a technology suitable for application to a waveguide two-channel rotary joint used for connecting waveguides in satellite communication antennas and weather radars, for example.

Conventionally, as a mechanism for connecting waveguides in equipment, for example, used for satellite communication antennas and weather radars, a hollow center section having a circular or rectangular cross section and extending in a cylindrical shape is provided in the center, a first waveguide having a first propagation path on one side and a second propagation path on the other side arranged in one tube; a coaxial waveguide that is rotatably supported by a shaft and has first and second transmission lines that communicate with the perpendicular axis to the first and second propagation paths for mode conversion, respectively; A sectioned region of one waveguide includes a short-circuit plate partitioned by obliquely extending a plurality of steps, a first transmission line of a coaxial waveguide connected to the short-circuit plate and communicating with the first propagation path side, a first A waveguide 2-channel rotary joint is known in which a second transmission line of a coaxial waveguide that surrounds and extends around the transmission line and communicates with the second propagation path side is disposed (see Patent Document 1. ).

JP 2013-255200 A

By the way, in a composite coaxial structure in which two signals are separately transmitted, it is necessary to ensure good isolation.

Therefore, the present invention provides a choke structure that can realize a structure that ensures good isolation in a waveguide two-channel rotary joint and that can solve the problems that occur with the structure. intended to

In order to solve the above problems, a choke structure according to the present invention includes a rotating waveguide section including a first waveguide and a second waveguide, and a fixed body that rotatably supports the rotating waveguide section. and a fixed waveguide section comprising a third waveguide and a fourth waveguide, wherein the coaxial waveguide of said rotating waveguide section is inserted. A first choke portion provided on the side of the communication portion between the hollow hole of the stationary body and the fourth waveguide, and a second choke portion provided on the side of the communication portion between the hollow hole and the third waveguide. a choke portion; a partition member interposed between the first choke portion and the second choke portion and having an inner tube through-hole for penetrating the inner tube of the coaxial tube; a bearing member that is housed inside the second choke portion and supports the inner tube of the coaxial tube so as to be axially rotatable; A through-hole for draining liquid is provided for communicating the first choke portion and the second choke portion.

In the choke structure according to the present invention, the first choke portion and the second choke portion absorb a change in wavelength due to the housing of the bearing member so that the first choke portion and the second choke portion have similar electrical characteristics. The dimensions of each part of the first choke part and each part of the second choke part may be different from each other.

In the choke structure according to the present invention, the partition member may be provided with two to four liquid drain through-holes.

According to the choke structure according to the present invention, since it has two choke portions, the first choke portion and the second choke portion, sufficient isolation is ensured in the waveguide two-channel rotary joint. It becomes possible to realize a structure to ensure.

According to the choke structure according to the present invention, the partition member interposed between the first choke portion and the second choke portion communicates the first choke portion and the second choke portion. Since the through hole is provided, the cleaning liquid that has entered the second choke portion can be discharged to the outside. It is possible to solve the problem.

In the choke structure according to the present invention, the first choke portion absorbs the change in wavelength due to the accommodation of the bearing member, and the first choke portion and the second choke portion have similar electrical characteristics. and the second choke portion have different dimensions, it is possible to increase isolation between channels in the same frequency band.

In the choke structure according to the present invention, when a plurality of liquid drain through holes are provided in the partition member, the cleaning liquid that has entered the second choke portion is more easily and appropriately discharged to the outside. becomes possible.

1 is a longitudinal sectional view showing a schematic internal structure of a waveguide two-channel rotary joint (in particular, a fixed waveguide section) in an embodiment having a choke structure according to an embodiment of the invention; FIG. 2 is an enlarged vertical cross-sectional view of a choke structure of the waveguide two-channel rotary joint of FIG. 1; FIG. FIG. 10 is a vertical cross-sectional view of the fixed waveguide portion for explaining a state in which cleaning liquid remains in the second choke portion (when the partition member is not provided with a through-hole for draining liquid); FIG. 2 is a perspective view showing the structure of a partition member in the choke structure of the two-channel waveguide rotary joint of FIG. 1; FIG. 10 is a vertical cross-sectional view of the fixed waveguide section for explaining discharge of the cleaning liquid in the second choke section to the outside. This is a model of the waveguide 2-channel rotary joint 1 used in the simulation in the verification example, and is a model for simulation when the partition member is not provided with a through-hole for draining liquid. This is a model of the waveguide two-channel rotary joint 1 used in the simulation in the verification example, and is an example of a simulation model in the case where the partition member is provided with two through-holes for draining liquid. 5 is a graph showing a comparison of S-parameter S11 (return loss) for each case of presence/absence of a through-hole for draining liquid in a partition member and the shape of the through-hole for draining liquid. 7 is a graph showing a comparison of the S-parameter S33 (return loss) for each case of the presence or absence of a through-hole for draining liquid in the partition member and the shape of the through-hole for draining liquid. 4 is a graph showing a comparison of S-parameter S21 (insertion loss) for each case of the presence or absence of a through-hole for draining liquid in the partition member and the shape of the through-hole for draining liquid. 7 is a graph showing a comparison of the S-parameter S43 (insertion loss) for each case of the presence or absence of a through-hole for draining liquid in the partition member and the shape of the through-hole for draining liquid. 7 is a graph showing a comparison of S-parameter S13 (isolation) for each case of presence/absence of a through hole for draining liquid in a partition member and the shape of the through hole for draining liquid. 7 is a graph showing a comparison of the S-parameter S14 (isolation) for each case of the presence or absence of a through-hole for draining liquid in the partition member and the shape of the through-hole for draining liquid. 7 is a graph showing a comparison of the S-parameter S23 (isolation) for each case of the presence or absence of a through-hole for draining liquid in the partition member and the shape of the through-hole for draining liquid. 7 is a graph showing a comparison of the S-parameter S24 (isolation) for each case of the presence or absence of a through-hole for draining liquid in the partition member and the shape of the through-hole for draining liquid.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the illustrated embodiments. In the following description, as shown in the figure, a vertical axis and a horizontal axis that are perpendicular to each other are defined for the waveguide two-channel rotary joint 1, and the top and bottom correspond to each other along the vertical axis direction. and correspond to the right and left along the horizontal axis.

FIG. 1 is a longitudinal sectional view showing a schematic internal structure of a waveguide two-channel rotary joint 1 (in particular, a fixed waveguide section 10) in an embodiment having a choke structure 30 according to an embodiment of the invention. be. FIG. 2 is an enlarged longitudinal sectional view of the choke structure 30 of the waveguide two-channel rotary joint 1. FIG.

This waveguide two-channel rotary joint 1 converts a TE mode (Transverse Electric mode), which is a transmission fundamental mode of a hollow rectangular waveguide having a rectangular cross section, into a rotatable coaxial line TEM mode (Transverse Electromagnetic mode). A fixed waveguide section 10 having a function of mode conversion, which is mainly fixed to a turntable of a weather radar, for example, and a rotating waveguide supported rotatably on the upper portion of the fixed waveguide section 10 and

Here, the present invention relates to the fixed waveguide section 10, and the structure of the rotating waveguide section is specified as long as it has a coaxial waveguide 23 inserted into the fixed waveguide section 10. Since the structure of the rotating waveguide portion is not limited to the above-described embodiment, detailed description thereof will be omitted here.

The rotary waveguide section is, for example, a first waveguide that is a port that is fixed to a rotating body that is rotatably supported on the upper portion of the fixed waveguide section 10 and that outputs a vertically polarized wave (CH2). 21, a second waveguide 22 fixed to the rotating body and serving as a port for outputting the horizontally polarized wave (CH1), and transmitting the vertically polarized wave (CH2) to the first waveguide 21 and the second and a coaxial waveguide 23 for transmitting a horizontally polarized wave (CH1) to the waveguide 22. As a specific structure of such a rotating waveguide section, for example, The structure disclosed in Japanese Patent Application Laid-Open No. 2013-255200 (including the structure disclosed as background art and the structure disclosed as a mode for carrying out the invention) can be employed.

The fixed waveguide section 10 includes, for example, a fixed body 11 which is fixedly installed on a rotating table of a weather radar and which rotatably supports the rotating waveguide section; a third waveguide 12, which is a port for inputting the vertically polarized wave (CH2) transmitted from the rotating table to 23, and a fourth waveguide 13, which is a port for inputting the horizontally polarized wave (CH1); have

The fixed main body 11 is formed with an opening (reference numeral 111) at its upper end to accommodate the coaxial waveguide 23 extending downward from the rotating waveguide portion and arranged along the vertical direction, and to accommodate the third waveguide. It has a hollow hole 112 communicating with the tube 12 and the fourth waveguide 13 . A rotating member (not shown) such as a bearing is attached to the fixed body 11 near the upper end thereof, and the rotating waveguide portion is rotatably supported via the rotating member (for example, the above-mentioned JP 2013-255
200).

Each of the first to fourth waveguides 21 , 22 , 12 , 13 is a TE mode waveguide, which is a transmission fundamental mode of a hollow rectangular waveguide having a rectangular cross section. It communicates with the TEM mode coaxial tube 23 of the rotatable coaxial line extending into 112 .

The coaxial waveguide 23 has a composite coaxial structure for separately transmitting two polarized waves, and is a two-channel coaxial waveguide in which two transmission lines are formed, which is a TEM mode coaxial waveguide of a rotatable coaxial line. , is accommodated in the hollow hole 112 of the fixing body 11 .

The coaxial tube 23 includes a long inner tube 231 extending in a slender cylindrical shape so as to cover the periphery of the rod-shaped central conductor 24, a short cylindrical outer tube 232 covering the outside of the upper end portion of the inner tube 231, have 2, 3, and 5 do not show the coaxial waveguide 23 and the central conductor 24. FIG.

The coaxial tube 23 is also formed between the first transmission line 233, which is formed between the central conductor 24 and the inner tube 231 to transmit the vertically polarized wave (CH2), and the inner tube 231 and the outer tube 232. and a second transmission line 234 for transmitting horizontally polarized waves (CH1).

In the coaxial waveguide 23, the upper end of the first transmission line 233 communicates with the first waveguide 21 of the rotating waveguide portion, and the lower end of the first transmission line 233 communicates with the third waveguide 12, The upper end of the second transmission line 234 communicates with the second waveguide 22 of the rotating waveguide portion, and the lower end of the second transmission line 234 and the fourth waveguide 13 communicate with each other through the hollow hole 112 of the fixed main body 11 . communicates through That is, the first waveguide 21 and the third waveguide 12 are communicated through the inner tube 231 of the coaxial waveguide 23 (that is, the first transmission line 233), and the second waveguide 22 and the fourth waveguide are connected. It communicates with the wave tube 13 through the outer tube 232 of the coaxial waveguide 23 (that is, the second transmission line 234).

Here, the isolation between the vertically polarized wave (CH2) inputted and transmitted from the third waveguide 12 and the horizontally polarized wave (CH1) inputted and transmitted from the fourth waveguide 13, that is, In order to ensure sufficient isolation between channels, a choke structure 30 is provided between the communicating portion between the coaxial waveguide 23 and the third waveguide 12 and the communicating portion between the coaxial waveguide 23 and the fourth waveguide 13. is provided.

In order to ensure sufficient isolation between channels, the choke structure 30 has a communication portion (referred to as a “first communication portion 131”) between the hollow hole 112 of the fixed body 11 and the fourth waveguide 13. The first choke portion 31 provided on the side (that is, the upper side) and the communicating portion (referred to as “second communicating portion 121”) between the hollow hole 112 of the fixed body 11 and the third waveguide 12 ( That is, it has two choke portions with the second choke portion 32 provided on the lower side). The first choke portion 31 and the second choke portion 32 are provided as a hollow space communicating with the hollow hole 112 of the fixed main body 11 between the first communication portion 131 and the second communication portion 121 .

For the convenience of molding and assembly, the fixed waveguide portion 10 is configured by combining a plurality of pieces, and in relation to the choke structure 30, the side on which the first choke portion 31 is provided and the side on which the first choke portion 31 is provided. 2 are formed as separate pieces (reference numeral BS in FIGS. 1, 3, and 5 represents the joining surface of the pieces).

A choke structure 30 according to an embodiment includes a rotating waveguide portion including a first waveguide 21 and a second waveguide 22, a fixed body 11 that rotatably supports the rotating waveguide portion, and a third waveguide. A choke structure in a waveguide two-channel rotary joint 1 having a fixed waveguide section 10 comprising a waveguide 12 and a fourth waveguide 13, wherein the coaxial waveguide 23 of said rotating waveguide section is inserted. A first choke portion 31 provided on the side of a communication portion between the hollow hole 112 of the fixed body 11 and the fourth waveguide 13, and a communication portion between the hollow hole 112 of the fixed body 11 and the third waveguide 12 and an inner pipe through hole 331 interposed between the first choke portion 31 and the second choke portion 32 and allowing the inner pipe 231 of the coaxial pipe 23 to pass therethrough. It has a partition member 33 and a bearing member 34 that is accommodated inside the second choke portion 32 and supports the inner tube 231 of the coaxial tube 23 so as to be axially rotatable. A liquid draining through hole 332 for communicating the first choke portion 31 and the second choke portion 32 is provided on the periphery of the .

The first choke portion 31 is provided as a hollow space having a first choke portion space 311 and a first choke groove 312, and the second choke portion 32 is provided as a hollow space having a second choke portion space 321 and a second choke groove. 322 is provided as a hollow space.

A first choke portion space 311 is formed on the side of the first communication portion 131 in the fixed body 11 as a circular hollow space having a predetermined height in plan view, in other words, as a columnar hollow space.

The first choke groove 312 is formed as an annular groove recessed upward from the peripheral edge of the top surface/top surface of the first choke space 311, and therefore the bottom surface is open.

A second choke portion space 321 is formed on the side of the second communication portion 121 in the fixed body 11 as a circular hollow space having a predetermined height in plan view, in other words, as a cylindrical hollow space.

The second choke groove 322 is formed as an annular groove that is recessed downward from the periphery of the bottom/bottom surface of the second choke space 321 and thus has an open top surface.

The bearing member 34 is a member that supports the inner tube 231 of the coaxial tube 23 so that the inner tube 231 is axially rotatable. The bearing member 34 has a disk shape as a base, and has a through hole 341 in the center in a plan view for allowing the inner tube 231 of the coaxial tube 23 to pass therethrough. have

The bearing member 34 is accommodated in the second choke portion 32 with the downward annular convex portion inserted into the second choke groove 322 .

Although the material of the bearing member 34 is not limited to a specific type, for example, polytetrafluoroethylene (PTFE) can be used.

Here, since the bearing member 34 is accommodated in the second choke portion 32, the dielectric constants of the material forming the bearing member 34 and the metal material forming the fixed waveguide portion 10 are different from each other. As a result, a wavelength change occurs in the second choke section 32 . For example, when the bearing member 34 is formed of a material (specifically, for example, polytetrafluoroethylene (PTFE)) having a dielectric constant higher than that of the metal material forming the fixed waveguide section 10, the Since the bearing member 34 is housed in the second choke portion 32 , wavelength shortening occurs in the second choke portion 32 .

Therefore, in order to ensure good isolation between channels in the same frequency band, the sizes of the first choke section 31 and the second choke section 32 (that is, the choke section spaces 311 and 321 and the choke sections The dimensions of each portion of the grooves 312 and 322) are provided as hollow spaces different from each other. That is, the dimensions of the choke structure of each of the first choke portion 31 and the second choke portion 32 absorb the wavelength change due to the housing of the bearing member 34, and the first choke portion 31 and the second choke portion 31 are adjusted and set so that the choke portions 32 of the two have similar electrical characteristics and the isolation between channels in the same frequency band is increased.

The partition member 33 is interposed between the first choke portion 31 and the second choke portion 32 to separate the first choke portion space 311 and the second choke portion space 321 from each other.

The partition member 33 has a disk-like base and an inner tube through-hole 331 for the inner tube 231 of the coaxial tube 23 to pass through at the center in plan view.

Here, when assembling the fixed waveguide part 10, a plurality of pieces are combined and joined by brazing to the joining surfaces BS of the pieces so as to ensure airtightness. I have to. In order to remove the flux after brazing, since the mechanical structure of the fixed waveguide part 10 after assembly is complicated, it is practically impossible to wipe off the flux using, for example, alcohol-soaked absorbent cotton and tweezers. However, it is necessary to immerse the assembled fixed waveguide section 10 in a predetermined cleaning liquid to dissolve it.

When the flux is dissolved by immersion in the cleaning liquid, the flux will not dissolve unless it is immersed in the cleaning liquid at a high temperature. Therefore, the fixed waveguide section 10 after assembly is immersed in the cleaning liquid at a high temperature. In this case, since the temperature of the fixed waveguide part 10 after assembly drops sharply when it is immersed in the cleaning liquid, the cleaning liquid that has entered the hollow hole 112 of the fixed main body 11 will disperse the bearing member 34 and the surroundings (specifically, , enters the second choke portion 32 from the boundary with the metal material of the second choke portion 32), and on the other hand, even if the assembled fixed waveguide portion 10 is removed from the cleaning liquid after immersion for a predetermined time, the bearing member A problem arises in that the cleaning liquid is not discharged from the boundary between 34 and the surrounding metal material, and the cleaning liquid remains in the second choke portion 32 (see FIG. 3).

Therefore, in the partition member 33, two liquid drain through holes are provided around the inner tube through hole 331 at a position where at least a portion of the second choke portion 32 overlaps in plan view (in other words, in the vertical direction). 332 is provided (see FIGS. 1, 2 and 4). The number of through-holes 332 for draining provided in the partition member 33 is not limited to two, and may be one, or may be three or more.

The liquid drain through-hole 332 is provided so as to allow the first choke portion 31 and the second choke portion 32 to communicate with each other. provided to communicate with each other.

As a result, the cleaning liquid that has entered the second choke portion 32 passes through the liquid drain through hole 332 of the partition member 33, the first choke portion 31, and the hollow hole 112 of the fixed main body 11, and passes through the fixed waveguide. It is discharged to the outside from an opening 111 at the upper end of the pipe portion 10 (see FIG. 5).

In order to more easily and appropriately discharge the cleaning liquid that has entered the second choke portion 32 to the outside, it is preferable that the partition member 33 is provided with a plurality of through-holes 332 for draining liquid. Furthermore, in consideration of controlling the influence on the electrical characteristics of the rotary joint to an appropriate level, it is preferable that the partition member 33 is provided with about 2 to 4 through-holes 332 for draining liquid.

According to the choke structure 30 according to the embodiment, since it has two choke portions, the first choke portion 31 and the second choke portion 32, sufficient isolation is achieved in the waveguide two-channel rotary joint. It is possible to realize a structure that reliably secures the ration.

According to the choke structure 30 according to the embodiment, the first choke portion 31 and the second choke portion 32 are arranged in the partition member 33 interposed between the first choke portion 31 and the second choke portion 32. Since the through-hole 332 for draining fluid is provided to communicate with the second choke portion 32, the cleaning fluid that has entered the second choke portion 32 can be discharged to the outside of the fixed waveguide portion 10. It is possible to solve the problems associated with the structure having the choke portions 31 and 32, the partition member 33, and the bearing member .

Further, according to the choke structure 30 according to the embodiment, the first choke portion 31 and the second choke portion 32 have similar electrical characteristics by absorbing the change in wavelength due to the housing of the bearing member 34. Since the dimensions of each part of the first choke part 31 and each part of the second choke part 32 are different from each other, it is possible to increase the isolation between channels in the same frequency band. .

In addition, according to the chalk structure 30 according to the embodiment, since a plurality of through-holes 332 for draining the partition member 33 are provided, cleaning liquid that has entered the second choke portion 32 can be more easily removed. It is possible to discharge to the outside easily and appropriately.

An example of verification of the choke structure according to the present invention will be described below with reference to FIGS. 8 to 15. FIG.

In this verification example, a simulation is performed using a model of the waveguide two-channel rotary joint 1 to determine the S parameter, and the electrical characteristics of the rotary joint due to the provision of the through hole 332 for draining the partition member 33 We grasped and verified the impact on

A model of the waveguide two-channel rotary joint 1 used in the simulation in this verification example is shown in FIGS. 6 and 7. FIG. FIG. 6 is a simulation model in which the partition member 33 is not provided with the through hole 332 for draining. FIG. 7 is an example of a simulation model in the case where the partition member 33 is provided with the through-holes 332 for liquid drainage. be.

In this verification example, the ports 1 to 4 and the first to fourth waveguides 21, 22, 12, 13 in the simulation are associated as follows.
Port 1: Second waveguide 22 (port for outputting horizontally polarized wave (CH1))
Port 2: fourth waveguide 13 (port for inputting horizontal polarized wave (CH1))
Port 3: first waveguide 21 (port for outputting vertically polarized wave (CH2))
Port 4: Third waveguide 12 (port for inputting vertically polarized wave (CH2))

In this verification example, in order to grasp and verify the influence on the electrical characteristics of the rotary joint due to the provision of the liquid drainage through hole 332 in the partition member 33, the case where the liquid drainage through hole 332 is not provided and the case where the liquid drainage The S-parameters were compared with the case where the through-holes 332 were provided. In addition, in order to understand and verify the influence of the difference in the number and diameter of the through-holes 332 for liquid drainage, the way in which the through-holes 332 for liquid drainage are provided was changed to 2 mm for diameters of φ2 mm, φ3 mm, φ4 mm, φ5 mm, φ6 mm, and φ7 mm. and four cases with a diameter of φ7 mm (referred to as “shape-like cases”) were set.

FIG. 8 shows the results of comparison of the S parameter S11 (that is, return loss) for each case of the presence or absence of the liquid drainage through hole 332 of the partition member 33 and the shape of the liquid drainage through hole 332. Also, the S parameter S33 ( That is, FIG. 9 shows the result of the comparison of the return loss.

From the results shown in FIGS. 8 and 9, it was confirmed that the presence or absence of the through-holes 332 for draining did not significantly change the behavior and degree of the return loss for each frequency. From the results shown in FIG. 8 and the results shown in FIG. 9, and depending on the number and diameter of the through-holes 332 for draining, at least within the range of the shape case set in this verification example, the return loss varies by frequency. It was confirmed that the behavior and degree of In either case, the return loss standard is satisfied in a predetermined frequency band (approximately 9 to 10 GHz) including the specification center frequency of 9.5 GHz in the simulation here.

FIG. 10 shows the result of comparison of the S parameter S21 (that is, insertion loss) by the presence or absence of the liquid drain through hole 332 in the partition member 33 and the shape of the liquid drain through hole 332, and the S parameter S43. (ie, insertion loss) comparison results are shown in FIG. Regarding the comparison of the S parameters S21 and S43, four cases with a diameter of φ7 mm are not set as to how the through-holes 332 for draining are provided.

From the results shown in FIGS. 10 and 11, it was confirmed that the presence or absence of the through-holes 332 for draining did not significantly change the behavior and degree of the insertion loss for each frequency. From the results shown in FIG. 10 and the results shown in FIG. 11, and depending on the number and diameter of the through-holes 332 for draining, at least within the range of the shape case set in this verification example, the insertion loss is frequency It was confirmed that other behaviors and degrees did not change significantly. In both cases, the specification of insertion loss is satisfied in a predetermined frequency band (approximately 9 to 10 GHz) including the specified center frequency of 9.5 GHz in the simulation.

FIG. 12 shows the results of comparison of the S parameter S13 (that is, isolation) for each case of the presence or absence of the liquid drainage through hole 332 of the partition member 33 and the shape of the liquid drainage through hole 332, and the S parameter S14 (that is, FIG. 13 shows the result of comparison of S parameter S23 (ie, isolation), FIG. 14 shows the result of comparison of S parameter S24 (ie, isolation), and FIG. 15 shows the result of comparison of S parameter S24 (ie, isolation) shown in

From the results shown in FIGS. 12 to 15, it was confirmed that the isolation standard was satisfied in at least the range of shape cases set in this verification example.

From the results of the above verification example, the partition that intervenes between the first choke portion 31 and the second choke portion 32 and partitions the first choke portion space 311 and the second choke portion space 321 It was confirmed that even if the member 33 is provided with the inner tube through-hole 331, the electrical characteristics of the rotary joint are not greatly affected, and the performance satisfying the isolation standard can be exhibited.

Although the embodiments of the present invention have been described above, the specific configuration is not limited to the above-described embodiments. Included in the invention.

Specifically, in the above embodiment, the choke structure according to the present invention is applied to the waveguide two-channel rotary joint 1 whose structure is schematically shown in FIG. The structure of the waveguide two-channel rotary joint that can be applied is not limited to the waveguide two-channel rotary joint 1 whose schematic structure is shown in FIG. It may be applied to a two-channel rotary joint.

Further, although the bearing member 34 is accommodated in the second choke portion 32 in the above embodiment, the bearing member 34 may be accommodated in the first choke portion 31 . In this case, the cleaning liquid remains in the first choke portion 31, and the cleaning liquid that has entered the first choke portion 31 flows through the liquid drain through hole 332 of the partition member 33 and the second choke. It passes through the portion 32 and the hollow hole 112 of the fixed main body 11 and is discharged to the outside from the opening 111 at the upper end of the fixed waveguide portion 10 .

Reference Signs List 1 Waveguide 2-channel rotary joint 10 Fixed waveguide section 11 Fixed main body 111 Opening 112 Hollow hole 12 Third waveguide 121 Second communicating section 13 Fourth waveguide 131 First communicating section 21 First first Waveguide 22 Second waveguide 23 Coaxial waveguide 231 Inner tube 232 Outer tube 233 First transmission line 234 Second transmission line 24 Center conductor 30 Choke structure 31 First choke section 311 First choke section space 312 First first transmission line choke groove 32 second choke portion 321 second choke portion space 322 second choke groove 33 partition member 331 inner pipe through hole 332 liquid drain through hole 34 bearing member 341 through hole BS joint surface

Claims (3)

A rotating waveguide section comprising a first waveguide and a second waveguide, a fixed body rotatably supporting the rotating waveguide section, and a stationary guide comprising a third waveguide and a fourth waveguide. A choke structure in a waveguide two-channel rotary joint having a wave tube portion,
a first choke portion provided on the side of a communicating portion between the fourth waveguide and the hollow hole of the stationary body into which the coaxial waveguide of the rotating waveguide portion is inserted;
a second choke portion provided on the side of the communicating portion between the hollow hole and the third waveguide;
a partition member interposed between the first choke portion and the second choke portion and having an inner tube through hole through which the inner tube of the coaxial tube passes;
a bearing member that is accommodated inside the first choke portion or the second choke portion and supports the inner tube of the coaxial tube so as to be axially rotatable;
A liquid drain through hole for communicating the first choke portion and the second choke portion is provided around the inner pipe through hole of the partition member,
A choke structure characterized by: Each part of the first choke part and the said The dimensions of each part of the second choke part are different from each other,
A choke structure according to claim 1, characterized in that: 2 to 4 liquid drain through-holes are provided in the partition member,
3. The choke structure according to claim 1 or 2, characterized in that:

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