Waveguide connection member

Abstract

To provide a waveguide connection member capable of suppressing leakage of radio waves even when a waveguide and a counterpart member for connecting the waveguide are spaced apart in a pipe axis direction due to tolerance.SOLUTION: A waveguide connection member includes a first waveguide 1 having a first waveguide 10 for transmitting high frequencies and a flange 11. The flange 11 includes a flange end face 13 extending from the first open end 10a of the first waveguide 10 to the outside in the pipe radial direction RD, and a second flange outer peripheral surface 15 which is a part of a first flange outer peripheral surface 14 extending inward in the pipe axial direction AD from the flange end surface 13 and released outward in the pipe radial direction RD. The second flange outer peripheral surface is a surface formed in such a manner that a portion of the first flange outer peripheral surface of the flange 11 is recessed inward in the pipe radial direction RD. The electrical length from the first open end 10a of the flange end surface 13 to the second flange outer peripheral surface 15 along the pipe radial direction RD is (2×N+1) / 4 times the free space wavelength λ0, and N is an integer equal to or greater than 0.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a waveguide connection member for connecting waveguides that transmit high frequencies.

[0002] In devices that use high frequencies (e.g., microwaves) such as weather radars, waveguides are used as transmission paths for radio waves. When connecting a second waveguide to a first waveguide, it is necessary to connect the first waveguide and the second waveguide without any gaps. If there is a gap between the first waveguide and the second waveguide, radio waves will leak from that gap. As an example of a waveguide connection member, Patent Document 1 can be cited. As shown in Patent Document 1, when connecting waveguides to each other, it is common to bring the flange of the first waveguide into contact with the flange of the second waveguide so that there is no gap, and to fasten and join the flanges together with a fastening tool such as a bolt.

[0003] However, waveguides are made of metal and have tolerances as mechanical members. Even if an attempt is made to connect all waveguides that make up the transmission path without any gaps, a gap as a tolerance will occur between the waveguides that abut each other and their counterpart members at any waveguide connection portion in the transmission path. This tolerance can be reduced by fastening the flange of the waveguide with a fastening tool, but it is difficult to completely eliminate the gap.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides a waveguide connection member capable of suppressing radio wave leakage even when the connection counterpart members of the waveguides are separated in the tube axis direction due to tolerances.

Means for Solving the Problems

[0006] The waveguide connection member of the present disclosure includes a first waveguide having a first waveguide path for transmitting high-frequency waves and a flange. The flange has a flange end face extending outward in the tube diameter direction from a first opening end of the first waveguide path, and a second flange outer peripheral face which is a part of the first flange outer peripheral face extending inward in the tube axis direction from the flange end face and released outward in the tube diameter direction. The second flange outer peripheral face is a face formed in a shape in which a part of the flange end face in contact with the outer periphery of the flange is recessed inward in the tube axis direction, or a face formed in a shape in which a part of the first flange outer peripheral face of the flange is recessed inward in the tube diameter direction. The electrical length from the first opening end of the flange end face along the tube diameter direction to the second flange outer peripheral face is (2×N + 1) / 4 times the free space wavelength λ0, where N is an integer of 0 or more.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0008] [First Embodiment] Hereinafter, the waveguide connection member according to the first embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a perspective view showing a state in which the first waveguide 1 and the second waveguide 2 are butted against each other and fastened with a fastening member 4 such as a bolt. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, showing a cross-section passing through the tube axis A1 of the first waveguide 10 and showing the outer peripheral surface 15 of the second flange. In FIG. 2, for the sake of illustration, the first waveguide 1 and the second waveguide 2 are depicted in a separated state so as to have a gap. FIG. 3 is a front view of the flange end face 13 of the first waveguide 1 viewed along a line of sight parallel to the tube axis A1. FIG. 4 is a cross-sectional view perpendicular to the tube axis of the rectangular waveguide path.

[0009] The tube axis direction refers to a direction parallel to the tube axis A1 of the opening of the first waveguide 1 (near the first open end 10a). The tube diameter direction refers to a direction perpendicular to the tube axis A1 of the opening of the first waveguide 1. When the first waveguide 1 is bent, the tube axis of the opening on the tip side with respect to the bent portion is used as a reference.

[0010] As shown in FIGS. 1 to 3, the waveguide connection member according to the first embodiment has a first waveguide 1. The first waveguide 1 is connected to the second waveguide 2. The first waveguide 1 has a first waveguide path 10 for transmitting high frequency. The second waveguide 2 has a second waveguide path 20 for transmitting high frequency. The first waveguide 1 has a cylindrical portion 12 forming the first waveguide path 10, and a flange end face 13 extending outward in the tube diameter direction RD from the first open end 10a of the first waveguide path 10 at the tip of the cylindrical portion 12. The second waveguide 2 has a cylindrical portion 22 forming the second waveguide path 20 for transmitting high frequency, and a second waveguide end face 23 extending outward in the tube diameter direction RD from the second open end 20a of the second waveguide path 20 at the tip of the cylindrical portion 22. In the connected state, the first waveguide path 10 and the second waveguide path 20 are butted against each other. The connected state is a state in which the positional relationship between the first waveguide 1 and the second waveguide 2 is fixed by a fastening member 4 such as a bolt or a nut. In the connected state, it is preferable that the flange end face 13 of the first waveguide 1 and the second waveguide end face 23 of the second waveguide 2 are in contact with each other without a gap. This is because if there is a gap, radio waves will leak. However, assuming that a gap is generated between the flange end face 13 of the first waveguide 1 and the second waveguide end face 23 of the second waveguide 2, means for suppressing or reducing the leakage of radio waves are described below.

[0011] The first waveguide 1 and the second waveguide 2 are hollow metal tubes formed of a conductor. The first waveguide 1 and the second waveguide 2 are electrically shorted and set to ground. High-frequency waves are transmitted from one side to the other side of the first waveguide 1 and the second waveguide 2 in the tube axis direction AD. The high-frequency waves referred to in this specification are radio waves of 300 MHz or higher, preferably radio waves of 2 GHz or higher, and more preferably radio waves of 3 GHz or higher. Also, as an upper limit value, the high-frequency waves may be, for example, radio waves of 50 GHz or lower. More preferably, radio waves of 40 GHz or lower may be sufficient. The high-frequency waves may be microwaves or millimeter waves. In this embodiment, aluminum or stainless steel is used as the conductor, but any conductor may be used without being limited to these.

[0012] As shown in FIG. 4, the first waveguide 10 of the first embodiment is a rectangular waveguide 3 having a long side 31 and a short side 32 in the tube cross-section. The long sides 31 are parallel to each other, and the short sides 32 are parallel to each other. FIG. 2 is a cross-sectional view of the II-II portion in FIG. 1. The cross-section of the II-II portion is a cross-section passing through the center 31s of the long side 31 and the tube axis A1. In the waveguide, an oscillating electric field is generated by the traveling wave and the reflected wave. FIG. 4 is a schematic cross-sectional view orthogonal to the tube axis A1, which is a portion where the oscillating electric field is strong in the tube axis direction AD. As shown in FIG. 4, the oscillating electric field E forms a loop at the portion connecting the centers 31s of the long sides 31 and becomes the most dominant. On the other hand, no oscillating electric field E is generated on the short side 32. The high-frequency waves are transmitted through the rectangular waveguide 3 in the TE10 mode (Transverse Electric Mode), which is the basic mode of such a rectangular waveguide 3. In the TE10 mode, the electric field is not generated in the direction parallel to the long side 31 but in the direction parallel to the short side 32. Note that in modes other than the basic mode (TE10 mode), it is not limited to this, and modes other than TE10 can also be used.

[0013] As shown in FIGS. 1 to 3, the first waveguide 1 has a flange 11 formed at the tip of the cylindrical portion 12. The flange 11 includes a flange end face 13 extending outward in the tube diameter direction RD from the first opening end 10a of the first waveguide 10, and a second flange outer peripheral face 15 which is a part of the first flange outer peripheral face 14 extending inward in the tube axis direction AD from the flange end face 13 and opened to the outside in the tube diameter direction RD. In the first embodiment, the second flange outer peripheral face 15 is a face formed in a shape in which a part of the first flange outer peripheral face 14 is recessed inward in the tube diameter direction RD.

[0014] Specifically, as shown in FIG. 3, the first flange outer peripheral face 14 of the flange 11 includes the second flange outer peripheral face 15 and a third flange outer peripheral face 16 at the outermost end in the tube diameter direction RD. The third flange outer peripheral face 16 has a face 16a parallel to the long side 31 of the rectangular waveguide duct 3 and a face 16b parallel to the short side 32 of the rectangular waveguide duct 3. A part of the face 16a parallel to the long side 31 of the rectangular waveguide duct 3 is recessed inward in the tube diameter direction to form the second flange outer peripheral face 15. The second flange outer peripheral face 15 is arranged outside the tube diameter direction RD of the long side 31 of the rectangular waveguide duct 3. In a cross section (FIG. 2) passing through the tube axis A1 of the first waveguide 10 and where the second flange outer peripheral face 15 appears, the second flange outer peripheral face 15 extends from the flange end face 13 to the inner end 11a of the flange 11 in the tube axis direction. In the said cross section (FIG. 2), the second flange outer peripheral face 15 is the outermost face in the tube diameter direction. That is, the depression extending inward in the tube diameter direction in a part of the first flange outer peripheral face 14 of the flange 11 reaches the entire tube diameter direction, and a part of the first flange outer peripheral face 14 is in a state of being cut out when viewed with a line of sight parallel to the tube axis A1.

[0015] On the other hand, no depression is formed on the face 16b parallel to the short side 32 of the rectangular waveguide duct 3, and there is no second flange outer peripheral face 15. The reason why there is no second flange outer peripheral face 15 which is a depression on the face 16b parallel to the short side 32 of the rectangular waveguide duct 3 is that the radio wave leaking through a part (the part indicated by the dashed-dotted line in FIG. 3) passing through the tube axis A1 and the center 31s of the long side 31, parallel to the short side 32 and perpendicular to the long side 31 is dominant.

[0016] As shown in FIGS. 2 and 3, in order to reduce or prevent radio wave leakage, the electrical length EL1 from the first open end 10a of the flange end face 13 along the pipe diameter direction RD to the second flange outer peripheral surface 15 is 1 / 4 times the free space wavelength λ0. In the first embodiment, although the electrical length EL1 is 1 / 4 times the free space wavelength λ0, it is not limited thereto as long as the oscillating electric field E can be made a node (short) at the first open end 10a. For example, if it is (3λ0 / 4) or (5λ0 / 4), it can be made (2×N + 1) / 4 times the free space wavelength λ0. N is an integer of 0 or more, and examples of values that N can take are 0, 1, 2, 3, 4, 5, …. According to this configuration, even if a gap is generated between the flange end face 13 of the first waveguide 1 and the second waveguide end face 23 of the second waveguide 2, this gap is open to the outside in the pipe diameter direction, and the length of the gap in the pipe diameter direction becomes the above electrical length EL1. By doing so, the oscillating electric field E generated in this gap can be made an antinode (open) on the second flange outer peripheral surface 15 and a node (short) at the first open end 10a. As a result, even if a gap is generated between the first waveguide 1 and the second waveguide 2, it is possible to suppress the dominant (majority) radio wave leakage toward the outside in the pipe diameter direction.

[0017] As shown in FIG. 3, the flange 11 has an insertion hole 17 through which a fastening member 4 such as a bolt for fastening to a mating member (second waveguide 2) connected to the first waveguide 1 passes. The outer peripheral surface on the outside in the pipe diameter direction of the insertion hole 17 is the outer peripheral surface (third flange outer peripheral surface 16) of the first flange outer peripheral surface 14 other than the second flange outer peripheral surface 15. The third flange outer peripheral surface 16 is farther from the pipe axis A1 than the second flange outer peripheral surface 15. That is, the second flange outer peripheral surface 15 is formed by a depression while leaving the insertion hole 17 through which the fastening member 4 such as a bolt passes. The interval of the insertion holes 17 is determined by standards. In the first embodiment, the insertion holes 17 are arranged so as not to overlap the long side 31 when projected in a direction orthogonal to the long side 31 of the first waveguide 10. When viewed in a line of sight parallel to the direction orthogonal to the long side 31 of the first waveguide 10, it is preferable to provide a depression in the portion of the flange 11 that overlaps the long side 31 and arrange the second flange outer peripheral surface 15.

[0018] As shown in FIGS. 2 and 3, in the first embodiment, the angle P1 separating the flange end face 13 and the second flange outer peripheral surface 15 is parallel to the inner peripheral surface (long side 31) of the first waveguide 10. That is, the second flange outer peripheral surface 15, whose length from the inner peripheral surface (long side 31) of the first waveguide 10 is the electrical length EL1, extends in the circumferential direction of the tube. Thereby, it becomes possible to enhance the effect of suppressing radio wave leakage. In the first embodiment, the second flange outer peripheral surfaces 15 formed by the depressions are linearly arranged along the pair of long sides 31 of the rectangular waveguide duct 3, respectively. The second flange outer peripheral surfaces 15 are arranged at positions sandwiching the first waveguide 10 in the cross section where the pair of long sides 31 appear. As shown in FIG. 4, since the space between the centers 31s of the long sides 31 is the most dominant, it is preferable that the pair of second flange outer peripheral surfaces 15 sandwich the center 31s of the long side 31 and the vicinity thereof. Specifically, the second flange outer peripheral surface 15 is preferably arranged at a position that sandwiches at least from the outside in the tube diameter direction a region Ar1 that is 24% of the maximum width W1 of the long side 31 with the center 31s of the long side 31 as the center. This is because 60% of the power is distributed in this 24% region Ar1. Further, the second flange outer peripheral surface 15 is preferably arranged at a position that sandwiches at least from the outside in the tube diameter direction a region Ar1 that is 36% of the maximum width W1 of the long side 31 with the center 31s of the long side 31 as the center. This is because 81% of the power is distributed in this 36% region Ar1.

[0019] In the first embodiment, the first waveguide 1 is connected to the second waveguide 2. Similar to the first waveguide, the second waveguide 2 has a second waveguide path 20 that abuts against the first waveguide path 10 of the first waveguide 1, and a flange 21 that extends radially outward in the pipe diameter direction RD from the second open end 20a of the second waveguide path 20 and is fastened to the flange end face 13 of the first waveguide path 10 pipe. That is, both the first waveguide 1 and the second waveguide 2 are waveguides with flanges. The flange 21 of the second waveguide 2 is the same as that of the first waveguide 1. A depression is formed on the outer peripheral surface 24 of the first flange, a second outer peripheral surface 25 of the flange is formed by the depression, and the outer peripheral surface 24 of the first flange has the second outer peripheral surface 25 and the third outer peripheral surface 26. The electrical length along the pipe diameter direction RD from the second open end 20a to the second outer peripheral surface 25 of the flange on the second waveguide end face 23 is (2×N + 1) / 4 times the free space wavelength λ0. Since the depressions (the second outer peripheral surface 25 of the flange) for forming the electrical length are formed in both the first waveguide 1 and the second waveguide 2, the effect of suppressing radio wave leakage can be enhanced compared to the case where a depression is formed only on one flange.

[0020] As illustrated in FIG. 2, the distance D1 between the flange end face 13 of the first waveguide 1 and the second waveguide end face 23 is preferably 0.0 mm. However, even when the distance D1 exceeds 1.0 mm due to the cumulative value of the intersections of a plurality of mechanical parts constituting the transmission line, the effect of suppressing radio wave leakage continues. That is, by increasing the allowable value of the tolerance of the mechanical parts, the degree of freedom in the mechanical design of the waveguide is improved, and since a gap can be tolerated, the assembly work becomes easy.

[0021] <Other Embodiments> (1) In the first embodiment shown in FIGS. 1 to 4, as shown in FIG. 3, when viewed along a line of sight parallel to the pipe axis A1, the second outer peripheral surface 15 of the flange is formed by a rectangular depression, and the second outer peripheral surface 15 of the flange is linear and parallel to the inner peripheral surface (long side 31) of the rectangular waveguide path 3, but it is not limited to this. For example, in the second embodiment shown in FIG. 5, when viewed along a line of sight parallel to the pipe axis A1, the second outer peripheral surface 15 of the flange is formed by an arc-shaped depression, and the second outer peripheral surface 15 that satisfies the electrical length EL1 is narrower in the circumferential direction of the pipe than in FIG. 3.

[0022] (2) In the first embodiment shown in FIGS. 1 to 4, a depression is formed in the flange 21 of the second waveguide 2 to form the outer peripheral surface 25 of the second flange. However, the flange 21 of the second waveguide 2 may not have a depression. As long as only the first waveguide 1 has an electrical length from the first open end 10a to the outer peripheral surface 15 of the second flange that reaches the above value.

[0023] (3) In the first embodiment shown in FIG. 2, the depression in the flange 11 of the first waveguide 1 extends in the entire axial direction of the tube from the flange end face 13 to the inner end 11a in the axial direction of the flange 11, but it is not limited to this. For example, in the third embodiment shown in FIG. 6, the depression in the flange 11 of the first waveguide 1 extends from the flange end face 13 toward the inner side in the axial direction of the flange 11, but it is an example that does not reach the inner end 11a in the axial direction. As shown in FIG. 6, the outer peripheral surface 15 of the second flange is a surface formed in a shape where a part of the flange end face 13 in contact with the outer periphery of the flange 11 is recessed inward in the axial direction AD of the tube. In the cross section (FIG. 6) passing through the axial center A1 of the first waveguide 1 shown in FIG. 6 and where the outer peripheral surface 15 of the second flange appears, the flange 11 has a radially extending surface 18 that extends outward in the radial direction RD from the inner end P2 in the axial direction of the outer peripheral surface 15 of the second flange, which extends inward in the axial direction AD from the flange end face 13. The flange end face 13, the outer peripheral surface 15 of the second flange, and the radially extending surface 18 form a step. In this way, even when a part of the flange 11 cannot be entirely recessed in the axial direction AD, the outer peripheral surface 15 of the second flange can be formed, and leakage of radio waves can be suppressed. In the axial direction, the length D2 from the flange end face 13 to the radially extending surface 18 (the inner end P2 in the axial direction of the outer peripheral surface 15 of the second flange) only needs to be 2.0 mm or more, preferably 5.0 mm or more, for frequencies around 9.5 GHz.

[0024] (4) In the first embodiment, the pipeline is a rectangular waveguide pipeline 3 with a pipe cross-section having a long side 31 and a short side 32, but it is not limited to this. For example, as in the fourth embodiment shown in FIG. 7, the first waveguide 10 of the first waveguide tube may be a circular waveguide pipeline 103 with a circular pipe cross-section. The outer peripheral surface 15 of the second flange formed by the depression or step is arranged at a position that is line-symmetrical with the pipe axis A1 of the first waveguide 10 as the axis of symmetry. In the example shown in FIG. 7, the angle P1 separating the flange end face 13 and the outer peripheral surface 15 of the second flange is parallel to the inner peripheral surface of the first waveguide 10 and is formed in an arc shape parallel to the arc-shaped inner peripheral surface of the first waveguide 10 when viewed along a line of sight parallel to the pipe axis A1. Of course, as shown in FIG. 5, the above angle P1 may not be parallel to the inner peripheral surface of the first waveguide 10.

[0025] (5) In the first embodiment shown in FIG. 1, the mating member to which the first waveguide tube 1 is connected is the second waveguide tube, but the mating member is not limited to the waveguide tube. For example, as in the fifth embodiment shown in FIG. 8, the mating member 5 may be a non-pipe body such as the housing of the device. As shown in FIG. 8, the mating member 5 includes a housing 50 having a second waveguide 20 that abuts against the first waveguide 10 of the first waveguide tube 1, and a second waveguide end face 23 that extends radially outward in the pipe diameter direction from the second opening end 20a of the second waveguide 20 in the housing 50. The housing 50 has fastening holes 37 such as screw holes or bolt holes for stopping a fastening member passing through the insertion hole 17 of the first waveguide tube 1. The second waveguide end face 23 of the mating member 5 is wider in the pipe diameter direction than the flange 11 of the first waveguide tube 1. Even in such a connection form, since the outer peripheral surface 15 of the second flange is formed, the electrical length EL1 in the pipe diameter direction of the gap that may occur between the flange end face 13 and the second waveguide end face 23 becomes (2×N + 1) / 4 times the free space wavelength λ0, so it is possible to effectively suppress the leakage of radio waves.

[0026] (6) As in the first to fifth embodiments, the outer peripheral surface 15 of the second flange extends parallel to the pipe axis direction inward in the pipe axis direction from the outer end (P1) in the pipe diameter direction of the flange end face 13, but it is not limited to this. For example, the outer peripheral surface 15 of the second flange may extend inward in the pipe axis direction while being inclined with respect to the pipe axis direction from the outer end (P1) in the pipe diameter direction of the flange end face 13.

[0027] As described above, like the waveguide connection member of the first to fifth embodiments, the first waveguide 1 having the first waveguide 10 for transmitting high frequency and the flange 11 is provided. The flange 11 includes a flange end face 13 extending outward in the tube diameter direction RD from the first opening end 10a of the first waveguide 10, and a second flange outer peripheral face 15 which is a part of the first flange outer peripheral face 14 extending inward in the tube axis direction AD from the flange end face 13 and opened to the outside in the tube diameter direction RD. The second flange outer peripheral face is a face formed in a shape in which a part of the flange end face 13 in contact with the outer periphery of the flange is recessed inward in the tube axis direction AD, or a face formed in a shape in which a part of the first flange outer peripheral face of the flange 11 is recessed inward in the tube diameter direction RD. The electrical length from the first opening end 10a of the flange end face 13 along the tube diameter direction RD to the second flange outer peripheral face 15 may be (2×N + 1) / 4 times the free space wavelength λ0, where N is an integer of 0 or more.

[0028] When connecting the flange of the first waveguide 1 to the second waveguide 2 or the mating member 5 with a fastening member 4 such as a bolt, it is preferable that the second waveguide end face 23 of the second waveguide 2 or the mating member 5 and the flange end face 13 are in contact with each other and no gap is generated, but a gap may be generated. However, according to this configuration, even if a gap is generated between the flange end face 13 and the second waveguide end face 23, since the second flange outer peripheral face 15 is opened to the outside in the tube diameter direction RD, this gap is opened to the outside in the tube diameter direction RD and the length of the gap in the tube diameter direction RD is determined by the electrical length. If the electrical length along the tube diameter direction RD of the gap opened in the tube diameter direction RD is (2×N + 1) / 4 times the free space wavelength λ0 such as (λ0 / 4), (3λ0 / 4), (5λ0 / 4), the oscillating electric field E generated in this gap can be made a belly (open) on the second flange outer peripheral face 15 and a node (short) at the first opening end 10a. As a result of the oscillating electric field E becoming a node (short) at the first opening end 10a, even if a gap is generated, leakage of radio waves toward the outside in the tube diameter direction RD can be suppressed.

[0029] Although not particularly limited, like the waveguide connection member of the first to fifth embodiments, the flange 11 has an insertion hole 17 through which a fastening member 4 for fastening to a mating member [second waveguide 2, mating member 5] to which the first waveguide 1 is connected, and the outer peripheral surface outside the diameter direction RD of the insertion hole 17 may be the outer peripheral surface other than the second flange outer peripheral surface 15 of the first flange outer peripheral surface 14 (third flange outer peripheral surface 16). According to this configuration, since the second flange outer peripheral surface is formed by the depression while leaving the insertion hole 17 through which the fastening member 4 such as a bolt passes, it is possible to suppress the leakage of radio waves by the second flange outer peripheral surface 15 while ensuring the connection compatibility with other members by the fastening member 4 and the rigidity of the flange 11.

[0030] Although not particularly limited, like the waveguide connection member of the first to fifth embodiments, the angle P1 separating the flange end face 13 and the second flange outer peripheral surface 15 may be parallel to the inner peripheral surface of the first waveguide 10 as viewed along a line of sight parallel to the tube axis A1 of the first waveguide 1 path. According to this configuration, since the portion where the electrical length EL1 from the inner peripheral surface of the first waveguide 10 (first opening end 10a) to the second flange outer peripheral surface 15 becomes (2×N + 1) / 4 of the free space wavelength λ0 extends and spreads in the circumferential direction of the tube, it is possible to further suppress or prevent the leakage of radio waves.

[0031] Although not particularly limited, like the waveguide connection member of the first, second, fourth, and fifth embodiments, in the cross section (FIG. 2) passing through the tube axis A1 of the first waveguide 10 and where the second flange outer peripheral surface 15 appears, the second flange outer peripheral surface 15 may extend from the flange end face 13 to the inner end 11a in the tube axis direction of the flange end face 13, and the second flange outer peripheral surface 15 is the outermost surface in the diameter direction RD in the cross section. According to this configuration, since the second flange outer peripheral surface 15 is the outermost surface in the diameter direction RD in the cross section, the flange 11 is completely cut out in the tube axis direction AD, and the gap that may occur between the flange end face 13 and the second waveguide end face 23 becomes a space completely open in the diameter direction RD, so it is possible to further suppress or prevent the leakage of radio waves.

[0032] Although not particularly limited, as in the waveguide connection member of the third embodiment, in a cross section passing through the tube axis A1 of the first waveguide 10 and where the outer peripheral surface 15 of the second flange appears, the flange 11 may have a radially extending surface 18 that extends outward in the radial direction RD from the inner end in the tube axis direction AD of the outer peripheral surface 15 of the second flange that extends inward in the tube axis direction AD from the flange end surface 13, and the flange end surface 13, the outer peripheral surface 15 of the second flange, and the radially extending surface 18 form a step. According to this configuration, the outer peripheral surface 15 of the second flange can be formed by forming a step. Since the flange 11 has a portion that is not cut out inside the tube axis direction AD from the radially extending surface 18, even when the flange 11 cannot be completely cut out, the electrical length EL1 in the radial direction RD of the gap that may occur between the flange end surface 13 and the end surface 23 of the second waveguide can be made (2×N + 1) / 4 of the free space wavelength λ0, and leakage of radio waves can be suppressed or prevented.

[0033] Although not particularly limited, as in the waveguide connection member of the first to third embodiments, the first waveguide 10 may be a rectangular waveguide path 3 having a long side 31 and a short side 32 in the tube cross section, and the outer peripheral surface 15 of the second flange may be arranged outside the radial direction RD of the long side 31. According to this configuration, leakage of high frequency in the rectangular waveguide path 3 can be appropriately suppressed.

[0034] Although not particularly limited, as in the waveguide connection member of the fourth embodiment, the first waveguide 10 may be a circular waveguide path 103 having a circular tube cross section, and the outer peripheral surface 15 of the second flange may be arranged at a position that is line-symmetric with the tube axis A1 of the first waveguide 10 as the axis of symmetry. According to this configuration, since the electric field is largest along any radial direction RD passing through the tube axis A1 in the circular waveguide path 103, leakage of high frequency can be appropriately suppressed.

[0035] Although not particularly limited, it may further include a second waveguide 2 as in the waveguide connection member of the first to fourth embodiments. The second waveguide 2 has a second waveguide path 20 that abuts against the first waveguide path 10 of the first waveguide 1, and a flange 21 that extends outward in the radial direction RD of the pipe diameter from the second opening end 20a of the second waveguide path 20 and is fastened to the flange end face 13 of the first waveguide 1. Thus, it is applicable to fastening the flange 11 of the first waveguide 1 and the flange 21 of the second waveguide 2.

[0036] Although not particularly limited, it may further include a mating member 5 to which the first waveguide 1 is connected as in the waveguide connection member of the fifth embodiment. The mating member 5 has a second waveguide path that abuts against the first waveguide path 10 of the first waveguide 1, and a second waveguide path end face 23 that extends outward in the radial direction RD of the pipe diameter from the second opening end 20a of the second waveguide path 20. The second waveguide path end face 23 of the mating member 5 may be wider in the radial direction RD than the flange 11 of the first waveguide 1. Thus, it is applicable to fastening the flange 11 of the first waveguide 1 to a member larger than the flange 11 of the first waveguide 1, for example, a mating member 5 such as a housing of a device.

[0037] As described above, the embodiments of the present disclosure have been described with reference to the drawings. However, the specific configuration should be considered not to be limited to these embodiments. The scope of the present disclosure is shown not only by the description of the above embodiments but also by the claims, and further includes all changes within the meaning and scope equivalent to the claims.

[0038] It is possible to adopt the structure employed in each of the above embodiments in any other embodiment.

[0039] The specific configuration of each part is not limited to only the above-described embodiments, and various modifications are possible without departing from the gist of the present disclosure.

Description of Reference Numerals

[0040] 1 First waveguide 10 First waveguide path 10a First open end 11 Flange 13 Flange end face 14 First flange outer peripheral surface 15 Second flange outer peripheral surface 17 Insertion hole 18 Radially extending surface 2 Second waveguide (mating member) 20 Second waveguide 21 Flange 3 Rectangular waveguide duct 31 Long side 32 Short side 5 Mating member 103 Circular waveguide duct

Claims

1. A first waveguide tube having a first waveguide for transmitting high-frequency waves and a flange, The flange has a flange end face extending radially outward in the tube diameter direction from a first opening end of the first waveguide, and a second flange outer peripheral face which is a part of the first flange outer peripheral face extending radially inward in the tube axis direction from the flange end face and opened radially outward, The second flange outer peripheral face is a face formed in a shape in which a part of the first flange outer peripheral face of the flange is recessed radially inward, In the connection state of the first waveguide tube, the second flange outer peripheral face is opened radially outward, In a cross section passing through the tube axis of the first waveguide and where the second flange outer peripheral face appears, the second flange outer peripheral face extends from the flange end face to the inner end of the flange in the tube axis direction, and in the cross section, the second flange outer peripheral face is the outermost face in the tube diameter direction, The electrical length from the first opening end of the flange end face along the tube diameter direction to the second flange outer peripheral face is (2×N + 1) / 4 times the free space wavelength λ ０ where N is an integer of 0 or more, a waveguide tube connection member.

2. A first waveguide tube having a first waveguide for transmitting high-frequency waves and a flange, The flange has a flange end face extending radially outward in the tube diameter direction from a first opening end of the first waveguide, and a second flange outer peripheral face which is a part of the first flange outer peripheral face extending radially inward in the tube axis direction from the flange end face and opened radially outward, The second flange outer peripheral face is a face formed in a shape in which a part of the first flange outer peripheral face of the flange is recessed radially inward and a part of the flange end face in contact with the outer periphery of the flange is recessed radially inward, In the connection state of the first waveguide tube, the second flange outer peripheral face is opened radially outward, The electrical length from the first opening end of the flange end face along the tube diameter direction to the second flange outer peripheral face is (2×N + 1) / 4 times the free space wavelength λ0, where N is an integer of 0 or more, a waveguide tube connection member.

3. The flange has an insertion hole through which a fastening member that fastens to a mating member to which the first waveguide is connected passes, The outer peripheral surface on the outer side in the pipe diameter direction of the insertion hole is the outer peripheral surface of the first flange other than the outer peripheral surface of the second flange, In the flange, the surface on the outer side in the pipe axis direction where the insertion hole opens and the flange end face are flush. The waveguide connection member according to claim 1 or 2.

4. The outer peripheral surface of the second flange extending inward in the pipe axis direction from the flange end face is parallel to the inner peripheral surface of the first waveguide when viewed along a line of sight parallel to the pipe axis of the first waveguide. The waveguide connection member according to claim 1 or claim 2.

5. The first waveguide is a rectangular waveguide pipe having a long side and a short side in its cross-section, The outer peripheral surface of the second flange is arranged on the outer side in the pipe diameter direction of the long side. The waveguide connection member according to any one of claims 1 to 4.

6. The first waveguide is a circular waveguide pipe having a circular cross-section, The outer peripheral surface of the second flange is arranged at a position that is line-symmetric with respect to the pipe axis of the first waveguide as the axis of symmetry. The waveguide connection member according to any one of claims 1 to 4.

7. Further comprising a second waveguide, The second waveguide, A second waveguide that abuts against the first waveguide of the first waveguide, And a flange that extends outward in the pipe diameter direction from the second open end of the second waveguide and is fastened to the flange end face of the first waveguide. The waveguide connection member according to any one of claims 1 to 6.

8. Further comprising a mating member to which the first waveguide is connected, The mating member, A second waveguide that abuts against the first waveguide of the first waveguide, It has a second waveguide end face extending radially outward in the pipe diameter direction from the second open end of the second waveguide. The second waveguide end face of the mating member is wider in the pipe diameter direction than the flange of the first waveguide tube. The waveguide tube connection member according to any one of claims 1 to 6.

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