Waveguide

Abstract

To provide a waveguide that can ensure isolation while suppressing an increase in package size.SOLUTION: A waveguide 10 includes a first waveguide portion 20 in which a plurality of first waveguide holes 22 for propagating electromagnetic waves are formed, and a second waveguide portion 30 in which second waveguide holes 32 are formed to open facing the first waveguide holes 22. The second waveguide portion 30 is disposed with a predetermined gap from the first waveguide portion 20. The plurality of second waveguide holes 32 have elongated openings 321 that open on an opposing surface 301 of the second waveguide portion 30 facing the first waveguide portion 20. The direction along the major axis of the opening 321 of the second waveguide hole 32 is defined as the major axis direction. The plurality of second waveguide holes 32 include those disposed such that the major axis direction of one of the openings 321 of adjacent second waveguide holes 32 intersects with the major axis direction of the other of the openings 321 of the second waveguide holes 32.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a waveguide.

Background Art

[0002] Conventionally, it is known to install a waveguide provided with a plurality of waveguide holes for propagating electromagnetic waves transmitted and received by a launcher on a package including a plurality of launchers for transmitting and receiving electromagnetic waves (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventors of the present invention are examining a waveguide having a first waveguide tube portion provided with a plurality of first waveguide holes for propagating electromagnetic waves transmitted and received by a launcher, and a second waveguide tube portion provided with a plurality of second waveguide holes equal in number to the first waveguide holes so as to face the first waveguide holes.

[0005] In this type of waveguide, if a gap occurs between the first waveguide tube portion and the second waveguide tube portion, the isolation may deteriorate due to electromagnetic field leakage from the gap. On the other hand, for example, in some cases, isolation is ensured by securing a large distance between the openings of adjacent second waveguide holes, but widening the distance between the openings of the waveguide holes leads to an increase in the arrangement interval of the plurality of launchers, so an increase in the size of the package is inevitable.

[0006] An object of the present disclosure is to provide a waveguide capable of ensuring isolation while suppressing an increase in the size of a package.

Means for Solving the Problems

[0007] To achieve the above object, the inventors of the present invention intensively studied a waveguide. As a result, it was found that when the openings of adjacent second waveguide holes having an elongated hole shape are arranged such that their major axis directions intersect, the directions of the electric fields leaking from the adjacent openings intersect, and isolation can be ensured without widening the interval between the adjacent openings.

[0008] The invention according to claim 1 was devised based on the above finding. That is, the invention according to claim 1 is a waveguide applied to a package (PG) including a plurality of launchers (LCs) for transmitting and receiving electromagnetic waves, a first waveguide section (20) in which a plurality of first waveguide holes (22) for propagating electromagnetic waves transmitted and received by the launcher are formed, a second waveguide section (30) in which the same number of second waveguide holes (32) as the plurality of first waveguide holes are formed so as to open facing the first waveguide holes, the second waveguide section is arranged with a predetermined gap from the first waveguide section, in the plurality of second waveguide holes, an opening (321) that opens in a facing surface (301) of the second waveguide section facing the first waveguide section has an elongated hole shape, when the direction along the major axis of the opening in the second waveguide hole is defined as the major axis direction (DL), among the plurality of second waveguide holes, those arranged such that the major axis direction on one side of the opening of an adjacent second waveguide hole and the major axis direction on the other side of the opening of the second waveguide hole intersect are included.

[0009] According to this, isolation can be ensured without expanding the interval between the openings of adjacent second waveguide holes. For this reason, by bringing the openings of adjacent second waveguide holes closer and reducing the arrangement interval of the plurality of launchers, it is possible to suppress the enlargement of the package while ensuring isolation.

[0010] Here, the “elongated hole shape” means a shape including an elliptical shape, a shape similar to an elliptical shape, for example, a rounded rectangular shape, an oval shape, an oblong shape, a rectangular shape with chamfered corners, and the like.

[0011] Note that the reference signs in parentheses attached to each component etc. indicate an example of the correspondence relationship between the component etc. and the specific components etc. described in the embodiments described later.

Brief Explanation of Drawings

[0012]

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Embodiments for Carrying Out the Invention

[0013] An embodiment of the present disclosure will be described with reference to FIGS. 1 to 23. In this embodiment, an example in which the waveguide 10 of the present disclosure is applied to a radar device 1 for detecting a target in a vehicle will be described.

[0014] The radar device 1 emits electromagnetic waves toward the front of the vehicle, for example, and determines the distance to the target, the relative speed with respect to the host vehicle, the azimuth with respect to the host vehicle, etc. by receiving the electromagnetic waves reflected by the target in front of the vehicle. The radar device 1 employs the FMCW method as the signal modulation method. The operating frequency of the radio wave of the radar device 1 is set to a frequency band corresponding to millimeter waves (for example, 76.5 GHz).

[0015] As shown in FIG. 1, the radar device 1 includes a package PG including a plurality of launchers LC that transmit and receive electromagnetic waves, and a waveguide 10 installed on the package PG. The package PG and the waveguide 10 are connected via a joining member BM such as solder. In the case of the radar device 1 of the present embodiment, the structure in which the waveguide 10 is directly connected without using a printed circuit board or the like enables long-distance detection by reducing wiring loss.

[0016] As in the present embodiment, the configuration in which the waveguide 10 is installed on the package PG is called AOP or AIP, and enables simplification and miniaturization of the radar device 1, and thus is suitable for MIMO technology, which is wireless communication that requires a large number of antennas. Note that AOP is an abbreviation for Antenna On Package. Also, AIP is an abbreviation for Antenna In Package. MIMO is an abbreviation for Multi Input Multi Output.

[0017] The package PG is constituted by a semiconductor module such as LIP (for example, RFIC). Specifically, the package PG has a wiring board WB on which an antenna portion including a plurality of launchers LC is mounted, and a mold portion MP that seals the wiring board WB so that the antenna portion is exposed to the outside. Note that LIP is an abbreviation for Launcher In Package.

[0018] Among the propagation means for propagating electromagnetic waves, the waveguide 10 is suitable for propagating a high-frequency electromagnetic field because it has low electromagnetic wave propagation loss. As shown in FIG. 2, the waveguide 10 includes a first waveguide portion 20 and a second waveguide portion 30. The waveguide 10 is assembled with the first waveguide portion 20 and the second waveguide portion 30 having a predetermined gap therebetween. In FIG. 2, the gap between the first waveguide portion 20 and the second waveguide portion 30 is enlarged so that the opposing surfaces of the first waveguide portion 20 and the second waveguide portion 30 can be seen. Also, hereinafter, the gap between the first waveguide portion 20 and the second waveguide portion 30 is also referred to as "tube interval dg".

[0019] The first waveguide section 20 is composed of a thin plate member 21 such as a printed circuit board or a wiring board. In the thin plate member 21 of the first waveguide section 20, first waveguide holes 22 for propagating electromagnetic waves transmitted and received by the launcher LC are formed at respective sites corresponding to the launcher LC. That is, a plurality of first waveguide holes 22 for propagating electromagnetic waves transmitted and received by the launcher LC are formed in the first waveguide section 20.

[0020] The plurality of first waveguide holes 22 are formed by through holes penetrating the front and back of the thin plate member 21. The plurality of first waveguide holes 22 are formed by a drill or the like. Each first waveguide hole 22 has an opening shape that is substantially the same as the opening 321 of the second waveguide hole 32 described later. Although not shown, a metal film of about 1 μm containing aluminum, copper, silver, etc. is disposed in each first waveguide hole 22.

[0021] The second waveguide section 30 is composed of a plate member 31 having a thickness larger than that of the thin plate member 21. The second waveguide section 30 has a facing surface 301 facing the first waveguide section 20 and an outer surface 302 on the side opposite to the facing surface 301. In the second waveguide section 30, a plurality of second waveguide holes 32 penetrating the facing surface 301 and the outer surface 302 are formed, and a choke groove 33 surrounding at least a part of the second waveguide holes 32 with respect to the facing surface 301 is formed.

[0022] Here, although not shown, the second waveguide section 30 is configured by coating a resin molded product made of a resin material such as ABS or PPE with a metal film of about 1 μm containing aluminum, copper, silver, etc. Note that ABS is an abbreviation for Acrylonitrile Butadiene Styrene. Also, PPE is an abbreviation for Poly Phenylene Ether.

[0023] The second waveguide section 30 is formed, for example, by pouring molten resin into a mold and solidifying it to form a resin molded article in which the second waveguide holes 32 and the choke grooves 33 are formed, and then disposing a metal film on the entire surface of the resin molded article by sputtering, vapor deposition, or the like. Since the thickness of the metal film is sufficiently small with respect to the resin molded article, the illustration of the metal film is omitted in each drawing.

[0024] The second waveguide section 30 is formed with the same number of second waveguide holes 32 as the first waveguide holes 22 so as to open facing the first waveguide holes 22. The opening 321 that opens in the facing surface 301 of the second waveguide section 30 facing the first waveguide section 20 has a shape in which a TE mode in which the electric field vector of the electromagnetic wave is perpendicular to the direction in which the electromagnetic wave propagates is generated.

[0025] As shown in FIG. 3, the second waveguide hole 32 of the present embodiment has an elongated hole shape for the opening 321. In the present embodiment, the direction along the major axis of the opening 321 in the second waveguide hole 32 is defined as the major axis direction DL, and the direction along the minor axis of the opening 321 in the second waveguide hole 32 is defined as the minor axis direction DS.

[0026] Specifically, the opening 321 of the second waveguide hole 32 has a substantially oval opening shape. The opening 321 of the second waveguide hole 32 has a pair of major axis sides 322, 323 extending in the major axis direction DL, a first minor axis side 324 connecting one ends of the pair of major axis sides 322, 323, and a second minor axis side 325 connecting the other ends of the pair of major axis sides 322, 323. And the pair of major axis sides 322, 323 extend linearly along the major axis direction DL. Also, the first minor axis side 324 and the second minor axis side 325 have a substantially semi-circular arc shape.

[0027] The waveguide 10 configured as described above is assembled with a predetermined gap between the first waveguide portion 20 and the second waveguide portion 30 in order to accommodate warping or the like caused by differences in thermal expansion between the first waveguide portion 20 and the second waveguide portion 30. The first waveguide portion 20 and the second waveguide portion 30 are assembled, for example, by inserting an engaging convex portion formed on one of the first waveguide portion 20 and the second waveguide portion 30 into an engaging concave portion formed on the other. Note that the first waveguide portion 20 and the second waveguide portion 30 may be assembled by other methods.

[0028] Here, in the radar device 1, the azimuth resolution is improved by virtually increasing the number of antennas by means of MIMO technology using a plurality of transmitting antennas and a plurality of receiving antennas. In such a situation, an antenna with multi-channel transmission and reception is desired.

[0029] However, the package PG is generally sized at about a dozen millimeters square at the largest, and if multi-channel launchers LC are installed in this narrow range, there is a concern that the isolation will deteriorate due to inter-channel coupling.

[0030] Also, when the structure is such that there is a gap between the first waveguide portion 20 and the second waveguide portion 30 as in the waveguide 10 of the present embodiment, the isolation may deteriorate due to electromagnetic field leakage from the gap.

[0031] On the other hand, for example, it is conceivable to ensure a large interval between the openings 321 of adjacent second waveguide holes 32 in the second waveguide portion 30 to ensure the isolation between adjacent second waveguide holes 32.

[0032] However, when the interval between the openings 321 of adjacent second waveguide holes 32 is widened, it leads to an increase in the interval between adjacent first waveguide holes 22 and the arrangement interval of the plurality of launchers LC, so an increase in the size of the package PG is inevitable.

[0033] Based on these considerations, the inventors have intensively studied the waveguide 10 for which isolation can be ensured. Hereinafter, the results of the inventors' studies will be described with reference to FIGS. 4 to 7. FIGS. 4 to 7 show the relationship between the interval GAP between the openings 321 of the second waveguide holes 32, the isolation, and the passing characteristic S21 as the propagation characteristic of the waveguide 10 when the electromagnetic wave is propagated from the first waveguide section 20 side to the second waveguide section 30 side. In FIGS. 4 to 7, the shapes and dimensions of the openings 321 and the choke grooves 33 are the same conditions. Also, the frequency of the electromagnetic wave is set to the operating frequency of 76.5 GHz generally used in the millimeter-wave radar.

[0034] FIG. 4 shows the measurement results of the isolation when the second waveguide holes 32 are arranged such that the long axis sides 322 and 323 of the openings 321 of the adjacent second waveguide holes 32 face each other. As shown in FIG. 4, the isolation when the choke groove 33 is not formed around the opening 321 of the second waveguide hole 32 was found to be about -30 [dB] regardless of the interval GAP between the openings 321.

[0035] On the other hand, the isolation when the choke groove 33 is formed around the opening 321 of the second waveguide hole 32 was found to be smaller than that when the choke groove 33 is not formed. Also, the isolation was found to vary greatly depending on the interval GAP between the openings 321.

[0036] FIG. 5 shows the measurement results of the isolation when the second waveguide holes 32 are arranged such that the short axis sides 324 and 325 of the openings 321 of the adjacent second waveguide holes 32 face each other. As shown in FIG. 5, the isolation when the choke groove 33 is not formed around the opening 321 of the second waveguide hole 32 was found to be -40 [dB] or less. Also, the isolation was found to decrease as the interval GAP between the openings 321 increases.

[0037] On the other hand, when a choke groove 33 is formed around the opening 321 of the second waveguide hole 32, the isolation fluctuates in the range of -60 [dB] to -30 [dB]. Also, the isolation fluctuates significantly according to the interval GAP between the openings 321.

[0038] FIG. 6 shows the measurement results of the isolation when the second waveguide holes 32 are arranged such that the short axis sides 324 and 325 and the long axis sides 322 and 323 of the openings 321 of the adjacent second waveguide holes 32 face each other.

[0039] As shown in FIG. 6, when no choke groove 33 is formed around the opening 321 of the second waveguide hole 32, the isolation is -120 [dB] or less. Also, when a choke groove 33 is formed around the opening 321 of the second waveguide hole 32, the isolation is -140 [dB] or less. Also, the isolation fluctuates significantly according to the interval GAP between the openings 321.

[0040] From the measurement results shown in FIGS. 4 to 6 and the like, the inventors have obtained the knowledge that the isolation is significantly improved by arranging the openings 321 of the adjacent second waveguide holes 32 such that their respective long axis directions DL intersect.

[0041] FIG. 7 shows the measurement results of the transmission characteristic S21 when the second waveguide holes 32 are arranged such that the short axis sides 324 and 325 and the long axis sides 322 and 323 of the openings 321 of the adjacent second waveguide holes 32 face each other. The transmission characteristic S21 is a parameter indicating the transmission characteristic from the input to the output, and is also called the transmission loss.

[0042] As shown in FIG. 7, when no choke groove 33 is formed around the opening 321 of the second waveguide hole 32, regardless of the size of the interval GAP between the openings 321, about -0.5 [dB] of energy leaks.

[0043] On the other hand, when the choke groove 33 is formed around the opening 321 of the second waveguide hole 32, regardless of the size of the gap GAP between the openings 321, the energy becomes substantially zero [dB], and a result with almost no leakage was obtained.

[0044] From the measurement results shown in FIG. 7 and the like, the inventors have obtained the knowledge that by setting the choke groove 33 around the openings 321 of the adjacent second waveguide holes 32, the transmission characteristic S21 is improved compared to the case where there is no choke groove 33.

[0045] Based on these findings, the inventors have devised a connection structure of the waveguide 10 suitable for improving isolation and the transmission characteristic S21. In this connection structure, for improving isolation, the major axis directions DL of the respective openings 321 of the adjacent second waveguide holes 32 are arranged so as to intersect.

[0046] However, for example, as shown in FIG. 8, for the second waveguide holes 32 that are far apart beyond a predetermined value, a certain degree of isolation is ensured. For this reason, among the plurality of second waveguide holes 32, those with openings 321 adjacent to each other at an interval equal to or less than a predetermined value are arranged such that the major axis directions DL of the respective openings 321 intersect. Among the plurality of second waveguide holes 32, those with openings 321 adjacent to each other beyond a predetermined value (for example, 0.5 wavelength) may be arranged such that the major axis directions DL of the respective openings 321 intersect, or may be arranged such that the major axis directions DL of the respective openings 321 are substantially parallel. The “predetermined value” here is set to a distance at which a certain degree of isolation can be ensured. The distance at which a certain degree of isolation can be ensured is obtained, for example, by simulation, experiment, or the like.

[0047] Thus, with respect to the openings 321 of adjacent second waveguide holes 32, isolation can be ensured by arranging them such that their major axis directions DL are substantially orthogonal to each other. Note that the larger the angle formed by the major axis directions DL of adjacent openings 321 (i.e., the crossing angle), the better the isolation. Considering such characteristics, each of the second waveguide holes 32 is preferably arranged, for example, such that the crossing angle of the major axis directions DL of adjacent openings 321 falls within the range of 45° to 90°.

[0048] As described above, isolation can be ensured by devising the arrangement of the openings 321 of adjacent second waveguide holes 32. However, in a structure with a gap between each waveguide tube portion 20, 30, energy that becomes a factor of transmission loss diffuses through the gap. This may have an adverse effect on other waveguide holes. To avoid this, in the second waveguide tube portion 30 of the present embodiment, a choke groove 33 is formed between the openings 321 of adjacent second waveguide holes 32.

[0049] As shown in FIG. 9, the second waveguide tube portion 30 of the present embodiment is provided with six second waveguide holes 32. The openings 321 of the six second waveguide holes 32 are provided so as to be within the arrangement region PA of the package PG. Note that since there is no constraint on the size of the package PG with respect to the choke groove 33, it may be formed outside the arrangement region PA of the package PG.

[0050] Each of the second waveguide holes 32 formed in the second waveguide tube portion 30 is arranged such that the major axis directions DL of adjacent openings 321 are substantially orthogonal to each other. When the openings 321 of a plurality of second waveguide holes 32 arranged in a row in a predetermined direction are defined as a "waveguide hole row", in the second waveguide tube portion 30, two waveguide hole rows each consisting of the openings 321 of three second waveguide holes 32 are set in a direction orthogonal to the predetermined direction.

[0051] Each waveguide hole row is arranged such that the major axis direction DL of the opening 321 of the second waveguide hole 32 located at both ends and the major axis direction DL of the opening 321 of the second waveguide hole 32 located between the openings 321 of the second waveguide holes 32 located at both ends intersect.

[0052] Specifically, among the waveguide hole arrays, in the upper row of holes in the upper first row in the figure, the openings 321 of the second waveguide holes 32 located at both ends are arranged such that their major axis directions DL are substantially parallel to each other, and are substantially orthogonal to the minor axis direction DS of the openings 321 of the second waveguide holes 32 located therebetween. Further, among the waveguide hole arrays, in the lower row of holes in the second row in the upper part of the figure, the openings 321 of the second waveguide holes 32 located at both ends are arranged such that their minor axis directions DS are substantially parallel to each other, and are substantially orthogonal to the major axis direction DL of the openings 321 of the second waveguide holes 32 located therebetween.

[0053] Thus, in the upper row of holes and the lower row of holes of the present embodiment, the major axis directions DL of the openings 321 of the second waveguide holes 32 adjacent to each other vertically are arranged to be substantially orthogonal to each other.

[0054] Here, as shown in FIG. 10, in the first waveguide tube portion 20, six first waveguide holes 22 are opened at positions corresponding to the openings 321 of the second waveguide holes 32. The opening shape of the first waveguide holes 22 is the same as the shape of the openings 321 of the second waveguide holes 32.

[0055] Further, at least one choke groove 33 is provided between the openings 321 of adjacent second waveguide holes 32. In the second waveguide tube portion 30 of the present embodiment, choke grooves 33 are formed around the openings 321 of all the second waveguide holes 32.

[0056] Here, the present inventors have intensively studied the relationship between the groove depth dp of the choke groove 33 and the transmission characteristic S21, and obtained the results shown in FIG. 11. Note that FIG. 11 shows the results when the representative operating frequency of the electromagnetic wave is 76.5 GHz and the electrically effective wavelength λ is 3.92 [mm] (i.e., λ = 3.92 [mm]). Further, in FIG. 11, in the choke groove 33, the angle formed by a virtual line passing through one end of the arc portion along the arc in the second waveguide hole 32 and the arc center and a virtual line passing through the other end of the arc portion along the arc in the second waveguide hole 32 and the arc center is defined as the groove angle θ, and the results of changing the groove angle θ are shown. Note that FIG. 11 also shows the results of changing the groove depth dp of the choke groove 33 in the range from 0.8 [mm] to 1.8 [mm] in steps of 0.2 [mm].

[0057] As shown in FIG. 11, it was found that the transmission characteristic S21 approaches 0 as the groove angle θ increases. That is, it was found that the transmission characteristic S21 approaches 0 as the range surrounding the opening 321 of the second waveguide hole 32 in the choke groove 33 increases. And, it was found that the transmission characteristic S21 approaches 0 as the groove depth dp of the choke groove 33 increases.

[0058] In addition, the present inventors have intensively studied the relationship between the shape of the choke groove 33 and the transmission characteristic S21, and obtained the results shown in FIG. 12. FIG. 12 shows the transmission characteristic S21 when the choke groove 33 is an "O-shaped groove", a "C-shaped groove", or a "U-shaped groove". The "O-shaped groove" is a choke groove 33 having a shape surrounding the entire circumference of the opening 321 of the second waveguide hole 32. The "U-shaped groove" is a choke groove 33 obtained by removing a portion corresponding to one of the pair of short axis sides 324 and 325 in the "O-shaped groove". The "C-shaped groove" is a choke groove 33 obtained by removing portions corresponding to both of the pair of short axis sides 324 and 325 in the "O-shaped groove".

[0059] As shown in Fig. 12, it was found that the passing characteristic S21 according to the groove depth dp changes with an extreme value as the tube pitch dg increases. Specifically, when the tube pitch dg is 0.4 [mm], the optimum value of the passing characteristic S21 in the case of the "O-shaped groove" is that the groove depth dp is about 1.05 [mm], and in the case of the "U-shaped groove", the groove depth dp is about 1.15 [mm] for optimum, and in the case of the "C-shaped groove", the groove depth dp is about 1.35 [mm].

[0060] When manufacturing the second waveguide tube portion 30 using a mold as in the present embodiment, it is desirable that the groove depths dp of all the choke grooves 33 are unified. For example, when the groove depth dp of the choke groove 33 is unified to 1.4 [mm] and the tube pitch dg is 0.4 [mm], the passing characteristic S21 becomes worse for the "U-shaped groove" and the "O-shaped groove" compared to the "C-shaped groove". Therefore, it is desirable to suppress the deterioration of the passing characteristic S21 by setting the groove depth dp of the choke groove 33 to a value obtained by averaging the optimum values of the passing characteristic S21 in each of the "O-shaped groove", "U-shaped groove", and "C-shaped groove" (for example, 1.25 [mm]).

[0061] Alternatively, the choke groove 33 may be formed of at least one of the "O-shaped groove" and the "U-shaped groove", and the groove depth dp of the choke groove 33 may be set to a value obtained by averaging the optimum values of the passing characteristic S21 in the "O-shaped groove" and the "U-shaped groove" (for example, 1.1 [mm]). According to this, the passing characteristic S21 can be sufficiently ensured.

[0062] Here, for example, when the resin molded product of the second waveguide section 30 is made of an ABS resin, in order to ensure strength, it is necessary to secure a groove outer thickness dt, which is the thickness outside the choke groove 33, of 0.3 [mm] to 0.35 [mm] or more. For this reason, the configuration in which the choke groove 33 of an "O-shaped groove" is set around the opening 321 of the second waveguide section 30 becomes larger in the major axis direction DL than when the choke groove 33 of a "C-shaped groove" is set around the opening 321. For example, as shown in FIG. 13, the configuration in which the choke groove 33 of an "O-shaped groove" is set results in a larger interval between the openings 321 of adjacent second waveguide sections 30 than when the choke groove 33 of a "C-shaped groove" shown in FIG. 14 is set. The increase in the interval between the openings 321 of adjacent second waveguide sections 30 is a factor leading to an increase in the size of the package PG. That is, the configuration in which the choke groove 33 of an "O-shaped groove" is set contributes to an improvement in isolation, but there is a risk that the package PG will become larger.

[0063] Taking these into consideration, in the second waveguide section 30 of the present embodiment, a choke groove 33 of an "O-shaped groove" and a choke groove 33 of a "U-shaped groove" are provided on the opposing surface 301, respectively. In the present embodiment, as shown in FIG. 9, a choke groove 33 is provided so as to extend along at least one of each major axis side 322, 323, and the first minor axis side 324 and the second minor axis side 325 around the opening 321 of the second waveguide hole 32 that constitutes the waveguide hole array.

[0064] Specifically, in the second waveguide section 30, a choke groove 33 of an "O-shaped groove" is formed around the opening 321 of one second waveguide hole 32, and a choke groove 33 of a "U-shaped groove" is formed around the opening 321 of five second waveguide holes 32.

[0065] And the choke groove 33 of the "U-shaped groove" is provided such that the portion where the choke groove 33 is not formed faces the portion extending along the major axis sides 322 and 323 of the adjacent choke grooves 33. In other words, in the choke groove 33 of the "U-shaped groove", the portion extending along the minor axis sides 324 and 325 is provided on the opposite side of the portion facing the opening 321 of the choke groove 33 or the second waveguide hole 32. If it is configured in this way, leakage of electromagnetic waves to the outside from the portion where the choke groove 33 is not formed is suppressed.

[0066] In the second waveguide tube portion 30, when there is a margin in the space for providing the opening 321, it is desirable to preferentially arrange the choke groove 33 of the "O-shaped groove" over the choke groove 33 of the "U-shaped groove". Further, in the second waveguide tube portion 30, when there is no margin in the space for providing the opening 321, it is desirable to preferentially arrange the choke groove 33 of the "U-shaped groove" over the choke groove 33 of the "O-shaped groove". Note that the choke groove 33 of the "U-shaped groove" is preferably arranged such that the portion without a groove in the choke groove 33 is located on the side opposite to the adjacent openings 321.

[0067] Here, in the present embodiment, as shown in FIG. 15, the portion surrounding the opening 321 of the second waveguide hole 32 on the opposing surface 301 is defined as the first peripheral portion AR1, the second peripheral portion AR2, the third peripheral portion AR3, and the fourth peripheral portion AR4.

[0068] The first peripheral portion AR1 is a portion that continues in the minor axis direction DS of the opening 321 with respect to one of the pair of major axis sides 322 and 323 among the portions surrounding the opening 321 of the second waveguide hole 32. The second peripheral portion AR2 is a portion that continues in the minor axis direction DS of the opening 321 with respect to the other of the pair of major axis sides 322 and 323 among the portions surrounding the opening 321 of the second waveguide hole 32.

[0069] Further, the third peripheral portion AR3 is a portion that extends in the major axis direction DL along one of the short axis sides 324 and 325 among the portions surrounding the opening 321 of the second waveguide hole 32. The fourth peripheral portion AR4 is a portion that extends in the major axis direction DL along the other of the short axis sides 324 and 325 among the portions surrounding the opening 321 of the second waveguide hole 32.

[0070] In the second waveguide tube portion 30 of the present embodiment, the openings 321 of the plurality of second waveguide holes 32 are set with respect to the opposing surface 301 such that one to three of the peripheral portions AR1 to AR4 are non-opening portions where the opening 321 of the second waveguide hole 32 is not set. And each second waveguide hole 32 utilizes, for example, the non-opening portion in the second waveguide tube portion 30 as shown in FIG. 16, and a waveguide path 34 of electromagnetic waves connecting the opening of the opposing surface 301 and the opening of the outer surface 302 is drawn along a direction substantially parallel to the opposing surface 301.

[0071] Here, since it is desired to ensure sufficient isolation between the transmitting antenna and the receiving antenna compared to the isolation between the transmitting antennas and the isolation between the receiving antennas, they may be arranged with a Die sandwiched therebetween.

[0072] Based on this, in the radar device 1 of the present embodiment, for example, as shown in FIG. 17, a waveguide hole group 32A composed of the second waveguide holes 32 for transmitting electromagnetic waves and a waveguide hole group 32B composed of the second waveguide holes 32 for receiving electromagnetic waves are set with a distance of a predetermined value or more therebetween. According to this, isolation between the transmitting antenna and the receiving antenna can be ensured to a certain extent.

[0073] Here, FIG. 18 shows the isolation when the tube portion interval dg is changed from 0.1 [mm] to 0.4 [mm] in the case where a choke groove 33 of a C-shaped groove is provided around the second waveguide hole 32. Further, FIG. 19 shows the isolation when the tube portion interval dg of each second waveguide hole 32 is changed from 0.1 [mm] to 0.4 [mm] in the case where a choke groove 33 of a U-shaped groove or an O-shaped groove is provided around the second waveguide hole 32.

[0074] As shown in FIGS. 18 and 19, the isolation is improved when a choke groove 33 such as a U-shaped groove or an O-shaped groove is provided around the second waveguide hole 32, compared with the case where a choke groove 33 of a C-shaped groove is provided around the second waveguide hole 32. The same was true even when the tube interval dg was changed.

[0075] In the second waveguide tube portion 30 of the present embodiment, since a choke groove 33 such as a U-shaped groove or an O-shaped groove is provided around the opening 321 of the second waveguide hole 32, the isolation of the second waveguide hole 32 for transmission and the second waveguide hole 32 for reception can be sufficiently improved.

[0076] In the radar device 1 configured as described above, when an electromagnetic wave is output from the launcher LC of the package PG, the electromagnetic wave passes through the first waveguide hole 22 of the first waveguide tube portion 20 and reaches between the first waveguide tube portion 20 and the second waveguide tube portion 30. The electromagnetic wave that has reached between the first waveguide tube portion 20 and the second waveguide tube portion 30 is input into the waveguide path 34 from the opening 321 of the second waveguide hole 32 of the second waveguide tube portion 30, and then radiated into the external space through the opening formed in the outer surface 302. For example, when the launcher LC of the package PG receives an electromagnetic wave from the external space, the electromagnetic wave propagates in the opposite direction to the case where an electromagnetic wave is output from the launcher LC of the package PG described above.

[0077] The waveguide 1 described above includes a first waveguide tube portion 20 in which a plurality of first waveguide holes 22 are formed, and a second waveguide tube portion 30 in which the same number of second waveguide holes 32 as the plurality of first waveguide holes 22 are formed so as to open facing the first waveguide holes 22. The second waveguide tube portion 30 is disposed with a predetermined gap from the first waveguide tube portion 20. The plurality of second waveguide holes 32 have an opening 321 that opens on the facing surface 301 of the second waveguide tube portion 30 facing the first waveguide tube portion 20 and has a long hole shape. Assuming that the direction along the major axis of the opening 321 in the second waveguide hole 32 is the major axis direction DL. At this time, among the plurality of second waveguide holes 32, there are those arranged such that the major axis direction DL on one side of the opening 321 of the adjacent second waveguide holes 32 intersects the major axis direction DL on the other side of the opening 321 of the second waveguide holes 32.

[0078] According to this, isolation can be ensured without increasing the distance between the openings 321 of adjacent second waveguide holes 32. Therefore, by bringing the openings 321 of adjacent second waveguide holes 32 closer and reducing the arrangement distance of a plurality of launchers LC, it is possible to ensure isolation while suppressing the increase in size of the package PG.

[0079] In addition, the waveguide 10 has the following characteristics.

[0080] (1) Among the plurality of second waveguide holes 32, those with openings 321 adjacent to each other at an interval equal to or less than a predetermined value are feared to have deteriorated isolation. Therefore, among the plurality of second waveguide holes 32, those with openings 321 adjacent to each other at an interval equal to or less than a predetermined value are preferably arranged such that the major axis directions DL of the respective openings 321 intersect.

[0081] (2) Among the plurality of second waveguide holes 32, at least one choke groove 33 is provided between the openings 321 of the second waveguide holes 32 adjacent to each other at an interval equal to or less than a predetermined value. According to this, it is possible to suppress the deterioration of isolation due to electromagnetic waves leaking from the gap between the first waveguide portion 20 and the second waveguide portion 30 by the choke groove 33.

[0082] (3) At the opening 321 of the second waveguide hole 32, the leakage of the electromagnetic field from the long side 322, 323 is more significant than the leakage of the electromagnetic field from the short side 324, 325. Therefore, it is desirable that a choke groove 33 is provided around the opening 321 of the second waveguide hole 32 so as to extend along the major axis direction DL of the opening 321.

[0083] (4) The plurality of second waveguide holes 32 includes a waveguide hole row in which the openings 321 of three second waveguide holes 32 are arranged in a predetermined one direction. This waveguide hole row is arranged such that the major axis direction DL of the openings 321 of the second waveguide holes 32 located at both ends intersects with the major axis direction DL of the openings 321 of the second waveguide holes 32 located between the openings 321 of the second waveguide holes 32 located at both ends. According to this, by bringing the openings 321 of the three second waveguide holes 32 arranged in one direction closer and reducing the arrangement interval of the plurality of launchers LC, it is possible to suppress the enlargement of the package PG while ensuring isolation.

[0084] (5) The opening 321 of the second waveguide hole 32 has a pair of major axis sides 322, 323 extending in the major axis direction DL, a first minor axis side 324 connecting one ends of the pair of major axis sides 322, 323, and a second minor axis side 325 connecting the other ends of the pair of major axis sides 322, 323.

[0085] It is desirable that a choke groove 33 is provided around the opening 321 of the second waveguide hole 32 constituting the waveguide hole row so as to extend along at least one of the pair of major axis sides 322, 323 and the first minor axis side 324 and the second minor axis side 325.

[0086] (6) The second waveguide tube portion 30 is set such that one to three of the peripheral portions AR1 to AR4 are non-opening portions where the openings 321 of the second waveguide holes 32 are not set, and the openings 321 of the plurality of second waveguide holes 32 are set with respect to the facing surface 301. According to this, interference between the waveguide paths 34 of the second waveguide holes 32 with adjacent openings 321 can be avoided, so there is an advantage that it becomes easy to set a plurality of waveguide paths 34 in the second waveguide tube portion 30.

[0087] For example, as shown in FIGS. 20 and 21, when four sides of some of the openings 321 of the plurality of second waveguide holes 32 are surrounded by other openings 321, the waveguide paths 34 connected to some of the openings 321 will interfere with the waveguide paths 34 connected to other openings 321. In this case, for example, as shown in FIG. 22, it is necessary to make a device such as making the waveguide paths 34 intersect three-dimensionally inside the second waveguide tube portion 30, and the manufacturing cost will increase significantly.

[0088] Therefore, for example, as shown in FIG. 23, it is desirable that the openings 321 of the plurality of second waveguide holes 32 be set with respect to the opposing surface 301 such that at least one of the four sides of the opening 321 of the second waveguide hole 32 is an unopened portion.

[0089] Note that since the overall size, beam width, and gain of the antenna are in a proportional relationship, in the millimeter-wave radar device 1 that requires long-distance detection, the waveguide tube 10 that constitutes a part of the antenna becomes large with respect to the package PG. In the radar device 1, there is no space margin in the package PG, but there is a space margin in the waveguide tube 10, so it is also possible to set a complex waveguide path 34.

[0090] (7) The first waveguide tube portion 20 is installed on the package PG, and the electromagnetic waves transmitted and received by the plurality of launchers LC propagate through the plurality of first waveguide holes 22 and the plurality of second waveguide holes 32. In this way, if the structure is such that the propagation of the electromagnetic waves from the launcher LC and the electromagnetic waves to the launcher LC are performed by the waveguide tube 10 without passing through the wiring pattern, the loss during the propagation of the electromagnetic waves can be reduced. This greatly contributes to the improvement of the performance of the radar device 1.

[0091] (Modification example) Hereinafter, modifications of the above-described embodiments will be described. In the following modifications, parts that are the same as or equivalent to those described in the preceding embodiments may be given the same reference numerals, and the description thereof may be omitted. Further, in the modifications, when only a part of the components is described, the components described in the preceding embodiments can be applied to the other parts of the components. The following modifications can be partially combined with each other as long as there is no problem in the combination, even if not specifically stated.

[0092] (First Modification) For example, as shown in FIG. 24, four second waveguide holes 32 may be formed in the second waveguide section 30. The openings 321 of the four second waveguide holes 32 are provided so as to be within the arrangement region of the package PG. In this example, each of the four second waveguide holes 32 is arranged such that the major axis directions DL of adjacent openings 321 are substantially orthogonal. Specifically, the four second waveguide holes 32 are arranged such that the openings 321 thereof face the openings 321 of the other second waveguide holes 32 in both the minor axis direction DS and the major axis direction DL.

[0093] (Second Modification) For example, as shown in FIG. 25, a waveguide hole group 32A composed of second waveguide holes 32 for transmitting electromagnetic waves and a waveguide hole group 32B composed of second waveguide holes 32 for receiving electromagnetic waves may be arranged in the second waveguide section 30. At this time, if the major axis directions DL of adjacent ones among the openings 321 of the second waveguide holes 32 constituting the waveguide hole group 32A and the openings 321 of the second waveguide holes 32 constituting the waveguide hole group 32B intersect, the waveguide hole groups 32A and 32B can be arranged close to each other.

[0094] (Third Modification) For example, as shown in FIG. 26, the openings 321 of the four second waveguide holes 32 may be arranged in a substantially “+” shape. Specifically, each of the four second waveguide holes 32 may be arranged such that one of the short axis sides 324 and 325 is close.

[0095] (Fourth Modification Example) Note that, for a part of the plurality of second waveguide holes 32, for example, as shown in FIG. 27, those in which the major axis directions DL of the adjacent openings 321 are parallel may be included.

[0096] (Fifth Modification Example) In the second waveguide tube portion 30, for example, as shown in FIG. 28, a waveguide hole row in which four or more second waveguide holes 32 are arranged in a predetermined one direction may be formed. In the example shown in FIG. 28, since the major axis directions DL of the adjacent second waveguide holes 32 are arranged to intersect, the openings 321 of the respective second waveguide holes 32 can be brought closer, and the arrangement intervals of the plurality of launchers LC can be reduced. As a result, it is possible to ensure isolation while suppressing the enlargement of the package PG.

[0097] Also, in the example shown in FIG. 28, choke grooves 33 such as O-shaped grooves, U-shaped grooves, and C-shaped grooves are formed so that one choke groove 33 is provided between the openings 321 of the adjacent second waveguide holes 32. According to this, the openings 321 of the respective second waveguide holes 32 can be brought closer.

[0098] (Sixth Modification Example) Note that, in the second waveguide tube portion 30, for example, as shown in FIG. 29, choke grooves 33 such as O-shaped grooves and U-shaped grooves may be formed around the openings 321 of the second waveguide holes 32. According to this, compared with the case where the choke groove 33 of the C-shaped groove is included around the second waveguide hole 32, the isolation can be improved.

[0099] (Seventh Modification Example) Here, when the openings 321 of the three second waveguide holes 32 are arranged side by side, as shown in FIG. 30, it is desirable that the opening 321 of the central second waveguide hole 32 is arranged so as to overlap with the virtual line IL connecting the centers of the openings 321 of the second waveguide holes 32 at both ends.

[0100] However, as shown in, for example, FIG. 31, the second waveguide holes 32 may be arranged such that the openings 321 of the second waveguide holes 32 at both ends and the opening 321 of the central second waveguide hole 32 overlap in the major axis direction DL of the opening 321 of the central second waveguide hole 32.

[0101] Further, as shown in, for example, FIG. 32, the second waveguide holes 32 may be arranged such that the openings 321 of the second waveguide holes 32 at both ends and the opening 321 of the central second waveguide hole 32 do not overlap in the major axis direction DL of the opening 321 of the central second waveguide hole 32. In this case, it is desirable that the opening 321 of the central second waveguide hole 32 is arranged to overlap with the virtual line IL connecting the centers of the openings 321 of the second waveguide holes 32 at both ends.

[0102] (Eighth Modification Example) In the waveguide 10 of the above-described embodiment, the first waveguide portion 20 is set on the package PG, but it is not limited thereto. As shown in, for example, FIG. 33, the waveguide 10 may be configured such that the first waveguide portion 20 is formed as a part of the package PG and the electromagnetic waves transmitted and received by the plurality of launchers LC propagate through the plurality of first waveguide holes 22 and the plurality of second waveguide holes 32. Even in such a configuration, since the propagation of the electromagnetic waves from the launcher LC and the electromagnetic waves to the launcher LC is performed by the waveguide 10 without passing through the wiring pattern, the loss during the propagation of the electromagnetic waves can be reduced. This greatly contributes to the improvement of the performance of the radar device 1.

[0103] (Other Embodiments) As described above, the representative embodiments of the present disclosure have been described. However, the present disclosure is not limited to the above-described embodiments and can be variously modified as follows, for example.

[0104] In the above-described embodiment, the opening 321 of the second waveguide hole 32 has an oval shape as an example. However, the opening shape of the opening 321 may be a shape other than the oval shape as long as it is a long hole shape.

[0105] As in the above-described embodiment, it is desirable that the opening shape of the first waveguide hole 22 be the same as the shape of the opening 321 of the second waveguide hole 32. However, the present invention is not limited to this, and the opening shape of the first waveguide hole 22 may be different from the shape of the opening 321 of the second waveguide hole 32.

[0106] In the above-described embodiment, the second waveguide tube portion 30 in which the surface of the resin molded product is coated with a metal film is exemplified. However, the second waveguide tube portion 30 is not limited to this, and for example, it may be constituted by a metal molded product.

[0107] In the above-described embodiment, the operating frequency of the radio wave transmitted and received by the radar device 1 is set to a frequency corresponding to millimeter waves. However, the present invention is not limited to this, and the operating frequency of the radio wave transmitted and received by the radar device 1 may be a frequency other than millimeter waves.

[0108] As in the above-described embodiment, it is desirable that the choke groove 33 be formed in the opposing surface 301 of the second waveguide tube portion 30. However, in the waveguide 10, the choke groove 33 is not essential and may be omitted.

[0109] In the above-described embodiment, an example in which the waveguide 10 is applied to the radar device 1 for detecting a target in a vehicle has been described. However, the application target of the waveguide 10 can be applied to various devices other than the radar device for vehicles.

[0110] In the above-described embodiment, it goes without saying that the elements constituting the embodiment are not necessarily essential except in cases where it is explicitly stated that they are particularly essential and cases where they are considered to be clearly essential in principle.

[0111] In the above-described embodiment, when numerical values such as the number, numerical value, amount, and range of the components of the embodiment are mentioned, they are not limited to the specific number except in cases where it is explicitly stated that they are particularly essential and cases where they are clearly limited to a specific number in principle.

[0112] In the above-described embodiments, when referring to the shape, positional relationship, etc. of components and the like, unless otherwise specified or limited to a specific shape, positional relationship, etc. in principle, they are not limited to such shape, positional relationship, etc.

[0113] [Aspect of the present disclosure]

[0114] [First aspect] A waveguide applied to a package (PG) including a plurality of launchers (LCs) for transmitting and receiving electromagnetic waves, a first waveguide portion (20) in which a plurality of first waveguide holes (22) for propagating the electromagnetic waves transmitted and received by the launcher are formed; a second waveguide portion (30) in which a plurality of second waveguide holes (32) having the same number as the plurality of first waveguide holes are formed so as to open facing the first waveguide holes, the second waveguide portion is disposed with a predetermined gap from the first waveguide portion, in the plurality of second waveguide holes, an opening portion (321) that opens on a facing surface (301) of the second waveguide portion facing the first waveguide portion has an elongated hole shape, when the direction along the major axis of the opening portion in the second waveguide hole is defined as the major axis direction, among the plurality of second waveguide holes, those in which the major axis direction of the opening portion of one of the adjacent second waveguide holes intersects the major axis direction of the opening portion of the other second waveguide hole are included. A waveguide.

[0115] [Second aspect] Among the plurality of second waveguide holes, those in which the openings are adjacent to each other with an interval equal to or less than a predetermined value are arranged such that the major axis directions of the openings thereof intersect each other. The waveguide according to the first aspect.

[0116] [Third aspect] Among the plurality of second waveguide holes, at least one choke groove (33) is provided between the openings of the second waveguide holes adjacent to each other with an interval equal to or less than the predetermined value. The waveguide according to the second aspect.

[0117] [Fourth aspect] The waveguide according to any one of the first to third aspects, wherein a choke groove is provided around the opening of the second waveguide hole so as to extend along the major axis direction of the opening.

[0118] [Fifth aspect] The plurality of second waveguide holes include a waveguide hole row in which the openings of three of the second waveguide holes are arranged in a predetermined one direction, The waveguide according to the second aspect, wherein the waveguide hole row is arranged such that the major axis direction of the openings of the second waveguide holes located at both ends intersects the major axis direction of the openings of the second waveguide holes located between the openings of the second waveguide holes located at both ends.

[0119] [Sixth aspect] The plurality of second waveguide holes include a waveguide hole row in which four or more of the second waveguide holes are arranged in a predetermined one direction, The waveguide according to the second aspect, wherein the waveguide hole row is arranged such that the major axis directions of adjacent second waveguide holes intersect in the one direction.

[0120] [Seventh aspect] The opening of the second waveguide hole has a pair of major axis sides (322, 323) extending in the major axis direction, a first minor axis side (324) connecting one ends of the pair of major axis sides, and a second minor axis side (325) connecting the other ends of the pair of major axis sides, The plurality of second waveguide holes include a waveguide hole row in which four or more of the second waveguide holes are arranged in a predetermined one direction, The waveguide hole row is arranged such that the major axis directions of adjacent second waveguide holes intersect in the one direction, A choke groove is provided around the opening of the second waveguide hole constituting the waveguide hole row so as to extend along at least one of the pair of major axis sides and the first minor axis side and the second minor axis side. The waveguide according to the third aspect.

[0121] [Eighth aspect] The opening of the second waveguide hole has a pair of major axis sides (322, 323) extending in the major axis direction, a first minor axis side (324) connecting one ends of the pair of major axis sides, and a second minor axis side (325) connecting the other ends of the pair of major axis sides. Among the portions surrounding the opening of the second waveguide hole on the opposing surface, a portion continuous in the minor axis direction of the opening with respect to one of the pair of major axis sides is a first peripheral portion (AD1), a portion continuous in the minor axis direction with respect to the other of the pair of major axis sides is a second peripheral portion (AD2), a portion continuous in the major axis direction with respect to the first minor axis side is a third peripheral portion (AD3), and a portion continuous in the major axis direction with respect to the second minor axis side is a fourth peripheral portion (AD4). The openings of the plurality of second waveguide holes are set with respect to the opposing surface such that one to three of the first peripheral portion, the second peripheral portion, the third peripheral portion, and the fourth peripheral portion are non-opening portions where the opening of the second waveguide hole is not set. The waveguide according to any one of claims 1 to 7.

[0122] [Ninth Aspect] The first waveguide section is installed on the package, and the electromagnetic waves transmitted and received by the plurality of launchers propagate through the plurality of first waveguide holes and the plurality of second waveguide holes. The waveguide according to any one of the first to eighth aspects.

[0123] [Tenth Aspect] The first waveguide section constitutes a part of the package, and the electromagnetic waves transmitted and received by the plurality of launchers propagate through the plurality of first waveguide holes and the plurality of second waveguide holes. The waveguide according to any one of the first to eighth aspects.

Explanation of Reference Numerals

[0124] 10 Waveguide 20 First waveguide section 22 First waveguide hole 30 Second waveguide section 301 Opposing surface 32 Second waveguide hole 321 Opening LC Launcher PG Package

Claims

1. A waveguide applied to a package (PG) including a plurality of launchers (LC) for transmitting and receiving electromagnetic waves, a first waveguide portion (20) in which a plurality of first waveguide holes (22) for propagating the electromagnetic waves transmitted and received by the launcher are formed; a second waveguide portion (30) in which a plurality of second waveguide holes (32) equal in number to the plurality of first waveguide holes are formed so as to open facing the first waveguide holes, and the second waveguide portion is disposed with a predetermined gap from the first waveguide portion, in the plurality of second waveguide holes, an opening portion (321) that opens on a facing surface (301) of the second waveguide portion facing the first waveguide portion is formed in an elongated hole shape, when the direction along the major axis of the opening portion in the second waveguide hole is defined as the major axis direction, among the plurality of second waveguide holes, those in which the major axis direction of the opening portion of one of the adjacent second waveguide holes intersects the major axis direction of the opening portion of the other second waveguide hole are included. A waveguide.

2. Among the plurality of second waveguide holes, those in which the openings are adjacent to each other with an interval equal to or less than a predetermined value are arranged such that the major axis directions of the openings thereof intersect each other. The waveguide according to claim 1.

3. Among the plurality of second waveguide holes, at least one choke groove (33) is provided between the openings of the second waveguide holes adjacent to each other with an interval equal to or less than the predetermined value. The waveguide according to claim 2.

4. Around the opening portion of the second waveguide hole, the choke groove is provided so as to extend along the major axis direction of the opening portion. The waveguide according to claim 3.

5. Among the plurality of second waveguide holes, a waveguide hole row in which the openings of three second waveguide holes are arranged in a predetermined one direction is included, the waveguide hole row is arranged such that the major axis direction of the opening portion of the second waveguide hole located at both ends intersects the major axis direction of the opening portion of the second waveguide hole located between the opening portions of the second waveguide holes located at both ends. The waveguide according to claim 2.

6. Among the plurality of second waveguide holes, a waveguide hole row in which four or more second waveguide holes are arranged in a predetermined one direction is included, the waveguide hole row is arranged such that the major axis directions of the adjacent second waveguide holes in the one direction intersect each other. The waveguide according to claim 2.

7. The opening of the second waveguide hole has a pair of major axis sides (322, 323) extending in the major axis direction, a first minor axis side (324) connecting one ends of the pair of major axis sides, and a second minor axis side (325) connecting the other ends of the pair of major axis sides. A plurality of the second waveguide holes include a waveguide hole row in which four or more of the second waveguide holes are arranged in a predetermined one direction. The waveguide hole row is arranged such that the major axis directions of the adjacent second waveguide holes in the one direction intersect. The choke groove is provided around the opening of the second waveguide hole constituting the waveguide hole row so as to extend along at least one of the pair of major axis sides, the first minor axis side, and the second minor axis side. The waveguide according to claim 3.

8. The opening of the second waveguide hole has a pair of major axis sides (322, 323) extending in the major axis direction, a first minor axis side (324) connecting one ends of the pair of major axis sides, and a second minor axis side (325) connecting the other ends of the pair of major axis sides. Among the portions surrounding the opening of the second waveguide hole on the opposing surface, a portion continuous in the minor axis direction of the opening with respect to one of the pair of major axis sides is a first peripheral portion (AD1), and a portion continuous in the minor axis direction with respect to the other of the pair of major axis sides is a second peripheral portion (AD2), a portion continuous in the major axis direction with respect to the first minor axis side is a third peripheral portion (AD3), and a portion continuous in the major axis direction with respect to the second minor axis side is a fourth peripheral portion (AD4). The openings of the plurality of second waveguide holes are set with respect to the opposing surface such that one to three of the first peripheral portion, the second peripheral portion, the third peripheral portion, and the fourth peripheral portion become non-opening portions where the opening of the second waveguide hole is not set. The waveguide according to claim 1 or 2.

9. The first waveguide tube portion is installed on the package, and electromagnetic waves transmitted and received by the plurality of launchers propagate through the plurality of first waveguide holes and the plurality of second waveguide holes. The waveguide according to claim 1 or 2.

10. The first waveguide tube portion constitutes a part of the package, and electromagnetic waves transmitted and received by the plurality of launchers propagate through the plurality of first waveguide holes and the plurality of second waveguide holes. The waveguide according to claim 1 or 2.

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