Radar device

Abstract

The present invention provides a radar device (1), comprising an antenna unit (2), a radome (4) and a housing (3). The antenna unit has an antenna surface, on which one or more antennas radiating radio waves are provided. The radome is formed of a material that transmits radio waves radiated by the antenna unit, and is arranged opposite to the antenna surface. The housing and the radome together form a space for accommodating the antenna unit. The housing surrounds the antenna surface, and has a blocking portion (11) at least in a portion of the peripheral portion of the housing that contacts the radome, the blocking portion protruding from the radome to the outside along the antenna surface.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS: This international application claims priority based on Japanese Patent Application No. 2019-121675 filed with the Japan Patent Office on June 28, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to a radar device. Background Art

[0003] Millimeter wave radars are known to be used for the purpose of autonomous driving of vehicles, collision prevention, etc. Millimeter wave radars are radars for detecting the presence of objects in a predetermined detection area and the distance to the objects by irradiating radio waves and detecting reflected waves of the irradiated radio waves reflected by the objects.

[0004] If the performance of the millimeter-wave radar is evaluated by mounting it on a vehicle, the performance of the millimeter-wave radar is degraded compared to when the radar is evaluated alone. This degradation occurs because the useless waves become interference waves that disturb the phase of the radar waves, thereby causing errors in the direction detection of the object, wherein the above-mentioned useless waves are radio waves that deviate from the detection area or go around to unexpected areas. As the main useless waves, it is known that there are reflected waves from the bumper.

[0005] Patent Document 1 discloses a technology in which an absorption element formed of a material that absorbs electromagnetic waves is provided on a housing of a radar device to suppress multiple reflections of unnecessary waves and reduce errors.

[0006] Patent Document 1: Japanese Patent Application No. 2015-507738

[0007] The following problems were found in the above radar device: Since an absorption element must be provided separately from the radar device, the manufacturing cost increases. In addition, a new problem was found: not only the reflected waves from the bumper, but also the useless waves radiated to the back of the radar are reflected by the vehicle body and become interference waves, which become factors causing azimuth detection errors. Summary of the invention

[0008] In one aspect of the present disclosure, it is preferable to provide a radar device having a new structure that reduces an error in direction detection by a radar.

[0009] One embodiment of the present disclosure is a radar device, comprising an antenna unit, a radome, and a housing. The antenna unit has an antenna surface, and the antenna surface is provided with one or more antennas that radiate radio waves. The radome is formed of a material that transmits radio waves radiated by the antenna unit, and the radome is arranged opposite to the antenna surface. The housing and the radome together form a space for accommodating the antenna unit. The housing surrounds the antenna surface, and has a blocking portion at least in a portion of the peripheral portion of the housing that contacts the radome, and the blocking portion protrudes outward from the radome along the antenna surface.

[0010] According to such a structure, by providing a blocking portion, it is possible to suppress the unnecessary waves propagating in the radome and radiating from the peripheral edge of the radome from heading toward the back of the radar device, and further suppress the unnecessary waves heading toward the back from becoming interference waves and causing errors in azimuth detection. In addition, since it is not necessary to provide an electromagnetic wave absorbing element or the like in order to reduce the azimuth detection error, it is also possible to reduce the manufacturing cost.

[0011] In addition, the reflected waves from the blocking part may also become interference waves, but this influence can be dealt with by designing the radar device itself, so the direction detection error can be easily reduced compared to the influence caused by the radiated waves toward the back which vary according to the installation environment and are difficult to deal with in advance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a top view showing the radar device according to the first embodiment.

[0013] Figure 2 It is a plan view of the radar device according to the first embodiment in a state where the radome is removed.

[0014] Figure 3 yes Figure 1 Cross-sectional view at line III-III in FIG.

[0015] Figure 4 yes Figure 1 Cross-sectional view at line IV-IV in FIG.

[0016] Figure 5 This is a graph showing the effect of improving the direction detection accuracy.

[0017] Figure 6 This is a graph showing the effect of improving directivity.

[0018] Figure 7 This is a graph showing the relationship between the width of the shielding surface and the back radiation power.

[0019] Figure 8 This is a graph showing the relationship between the depth of the groove and the back side radiation power.

[0020] Fig. 9 It is a top view showing a radar device according to a second embodiment.

[0021] Fig.10 yes Fig. 9 Cross-sectional view at line XX in FIG.

[0022] Fig.11 It is a top view showing a radar device according to a third embodiment.

[0023] Fig.12 yes Fig.11 Cross-sectional view at line XII-XII in FIG.

[0024] Fig.13 It is a plan view showing a radar device according to a fourth embodiment.

[0025] Fig.14 yes Fig.13 Cross-sectional view at line XIV-XIV in FIG. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0027] [1. First embodiment]

[0028] [1-1. Structure]

[0029] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0030] The radar device 1 of this embodiment is mounted on a vehicle, transmits radiation waves, and receives reflected waves of the radiation waves reflected by objects. The radiation waves are radio waves of a predetermined frequency, such as millimeter waves. The radar device 1 may include a transceiver circuit for transmitting and receiving radiation waves and reflected waves, a signal processing unit for processing received signals received by the transceiver circuit in order to obtain information about surrounding objects, and the like. The radar device 1 is, for example, set inside the bumper of a vehicle to detect various objects existing around the vehicle.

[0031] like Figure 1 to Figure 4 As shown, the radar device 1 includes an antenna unit 2, a housing 3, and a radome 4. The radar device 1 is fixed to a metal plate surface that is a part of a vehicle body 5 of the vehicle in a bumper.

[0032] The antenna unit 2 includes a rectangular antenna substrate 21. A plurality of antenna elements 22 for transmitting and receiving radio waves are provided on the first surface of the two surfaces of the antenna substrate 21. Hereinafter, the surface of the antenna substrate 21 on which the antenna elements 22 are formed is referred to as an antenna surface 23.

[0033] Here, the long side direction of the antenna substrate 21 is set as the x-axis direction, the short side direction is set as the y-axis direction, and the axial direction perpendicular to the antenna surface 23 is set as the z-axis direction. Hereinafter, the xyz three-dimensional coordinate axis is appropriately used for explanation. Among them, with the antenna surface 23 as the boundary, the side where the radiation wave is radiated is the positive side of the z-axis, and the opposite side is the negative side of the z-axis. In addition, the positive side of the z-axis is also called the front side of the antenna, and the negative side of the z-axis is called the back side of the antenna.

[0034] A plurality of antenna elements 22 are arranged two-dimensionally along the x-axis direction and the y-axis direction. Moreover, the plurality of antenna elements 22 arranged in a row along the y-axis direction each function as an array antenna (hereinafter referred to as a unit antenna). That is, the antenna unit 2 has a structure in which a plurality of unit antennas are arranged along the x-axis direction. Any one of the plurality of unit antennas is used as a transmitting antenna, and the other unit antennas are used as receiving antennas. That is, in the radar device 1, the x-axis direction, which is the arrangement direction of the unit antennas, is the azimuth detection direction.

[0035] However, the transmission antenna and the receiving antenna are not limited to this, and the number and configuration of the unit antennas used as the transmission antenna and the unit antenna used as the receiving antenna can be set arbitrarily. In addition, all the unit antennas can be used as transmission antennas, and all the unit antennas can be used as receiving antennas.

[0036] The housing 3 is made of a metal material and has a rectangular appearance. Together with the radome 4, it forms a space for accommodating the antenna unit 2. The housing 3 is provided with a housing recess 31, which is a recess for accommodating the antenna unit 2, on one surface. The depth of the housing recess 31 is set to be the same as the thickness of the antenna substrate 21. The antenna unit 2 is fixed so that the surface of the antenna substrate 21 opposite to the antenna surface 23 contacts the bottom surface of the housing recess 31. In other words, the housing 3 functions as a ground pattern for the antenna unit 2. In addition, the antenna unit 2 is fixed in the housing recess 31 in such a way that a gap for fixing the radome 4 is formed between the surface along the thickness direction of the antenna substrate 21, that is, the side surface, and the inner surface of the housing recess 31. In addition, the surface of the housing 3 opposite to the surface on which the housing recess 31 is formed is a fixing surface facing the vehicle body 5.

[0037] Furthermore, assuming that the wavelength of radio waves transmitted and received by the antenna unit 2 is λ, the width L of the housing edge portion 32 surrounding the housing recess 31 is set to L≤λ / 4, and the strength required for the housing 3 is ensured.

[0038] Hereinafter, the xyz axial directions of the antenna substrate 21 are also applied to the radar device 1 in which the antenna substrate 21 is mounted in the case recess 31 .

[0039] The two side walls at both ends of the housing 3 in the x-axis direction (i.e., the azimuth detection direction) are provided with grooves extending along the y-axis direction, i.e., choke grooves 33. The depth D of the choke groove 33 is set to D=λ / 4. However, strictly speaking, D=λ / 4 is not required, and a deviation within ±25% is also possible.

[0040] The radome 4 has a rectangular parallelepiped shape and a box-like shape with one side open. That is, the radome 4 has a cylindrical portion 42 formed in a rectangular cylindrical shape, and a plate-like portion 41 configured to close the first opening of the cylindrical portion 42. The radome 4 is formed of a dielectric that allows the radio waves transmitted and received by the antenna portion 2 to pass through with low loss. Among them, the relative dielectric constant of the dielectric is greater than 1. In the radome 4, the wavelength inside the radome is set to λg, and the thickness of the plate-like portion 41, which is a portion opposite to the antenna surface 23 of the antenna substrate 21, is set to λg / 2. Among them, the so-called wavelength inside the radome refers to the wavelength of the radio waves transmitted and received by the antenna portion 2 when propagating in the radome 4.

[0041] The radome 4 is fixed to the periphery of the housing recess 31 through the opening side of the cylindrical portion 42, covers the housing recess 31, and protects the antenna surface 23 of the antenna unit 2 accommodated in the housing recess 31. The radome 4 has two ends in the x-axis direction (i.e., the azimuth detection direction), such as Figure 4 As shown, the outer wall surface of the cylindrical portion 42 contacts the inner wall surface of the housing recess 31, and at both ends in the y-axis direction, as shown in FIG. Figure 3 As shown, the inner wall surface of the cylindrical portion 42 is fixed in contact with the outer wall surface of the housing 3. That is, at both ends of the radar device 1 in the y-axis direction, the radome 4 protrudes outward from the housing 3, and at both ends of the radar device 1 in the x-axis direction, the housing 3 protrudes outward from the radome 4 by the amount of the housing edge portion 32. Hereinafter, the portion of the housing edge portion 32 that protrudes from the radome 4 at both ends in the x-axis direction is referred to as the stopper 11. The width of the stopper 11 (i.e., the length protruding from the radome 4) is the same size as the width L of the housing edge portion 32.

[0042] The radar device 1 constructed in this way is fixed to the vehicle in such a manner that the y-axis direction is consistent with the vehicle height direction, the x-axis direction is consistent with the horizontal direction, and the z-axis direction is consistent with the center direction of the detection area. The so-called detection area is an area within a prescribed angle range with the center of the antenna surface 23 as the origin and the normal direction of the antenna surface 23, that is, the z-axis direction, as 0° in the xz plane. The prescribed angle range is set to, for example, -60° to +60°. The prescribed angle range is not limited to this and can also be set wider. The radiation waves radiated outside the detection area are called useless waves.

[0043] [1-2. Function]

[0044] In the radar device 1, the radiation wave radiated from the antenna unit 2 is radiated to the outside via the radome 4. A part of the radiation wave is reflected by the two boundary surfaces of the radome 4, but since the thickness of the radome 4 is set to λg / 2, the phases of the reflected wave on the inner side surface and the reflected wave on the outer side surface cancel each other, thereby suppressing the reflected wave from the radome 4 toward the antenna unit 2. In addition, a part of the radiation wave is multiply reflected in the radome 4 and radiated to the outside. Moreover, it radiates in various directions from the end of the radome 4 and also radiates in the back direction of the radar device 1. The unnecessary wave radiated in the back direction is reflected by the vehicle body 5 and radiated toward the front, interfering with the radiation wave radiated into the detection area, thereby causing an error in the azimuth detection. In particular, the influence of the unnecessary wave incident on the vehicle body 5 at an angle close to the z-axis (hereinafter referred to as a steep angle) is greater.

[0045] In the radar device 1, the blocking portions 11 provided at both ends in the azimuth detection direction reflect the unnecessary waves directed at such a steep angle toward the vehicle body 5. In addition, the choke slot 33 functions to cancel the unnecessary waves incident on the vehicle body 5 at a steep angle and passing near the side wall of the housing 3. That is, the reflected wave from the choke slot 33 is 180° out of phase with the incident wave to the choke slot 33, and thus has the function of canceling the unnecessary waves.

[0046] [1-3. Effect]

[0047] According to the first embodiment described in detail above, the following effects are achieved.

[0048] (1a) According to the radar device 1, by including the blocking portion 11, interference waves based on useless waves reflected by the vehicle body 5, which are difficult to predict before installation on the vehicle, can be suppressed, and thus the azimuth detection error caused by the useless waves can be suppressed. In addition, the reflected waves from the blocking portion 11 also become a factor that causes the azimuth detection error, but since the blocking portion 11 is a part of the radar device 1, a countermeasure can be formulated when designing the radar device 1 alone.

[0049] (1b) According to the radar device 1, since the direction detection error can be reduced without providing a radio wave absorbing element or the like, the manufacturing cost can be reduced.

[0050] (1c) According to the radar device 1 , by providing the choke groove 33 , a part of the unnecessary waves that are not reflected by the blocking portion 11 and are directed toward the vehicle body 5 can be cancelled, so that the direction detection error caused by the unnecessary waves can be further suppressed.

[0051] [1-4. Measurement]

[0052] Figure 5It shows the result obtained by simulating and calculating the error of azimuth detection in the range of -40° to +40° based on the signal obtained by the antenna unit 2. The solid line is an embodiment of the present disclosure, and the dotted line is a comparative example. In the embodiment, λ=12.4mm, L=λ / 4, and D=λ / 4. In addition, the comparative example is configured such that in the x-axis direction which is the azimuth detection direction, as in the y-axis direction, the antenna cover 4 is located outside the shell 3, thereby becoming a structure in which the blocking portion 11 does not exist, and a structure in which the choke slot 33 does not exist.

[0053] In both the embodiment and the comparative example, the error starts to increase after exceeding ±10°. However, it can be seen that the embodiment has a greater effect of suppressing the azimuth detection error.

[0054] Figure 6 1 and 2 show the results of measuring the directivity of the antenna unit 2. It can be seen that in the embodiment, the gain in the azimuths of ±90° or more, that is, the back direction is suppressed compared with the comparative example, that is, the unnecessary waves reflected by the vehicle body 5 are suppressed.

[0055] Figure 7 The figure shows the average value of the radiation power in the back direction (hereinafter referred to as the back radiation power) measured by changing the width L of the blocking portion 11 in the structure of the embodiment. When L≤λ / 4, the larger L is, the lower the average value of the back radiation power is, and when L>λ / 4, the average value of the back radiation power is approximately constant. In other words, regardless of the size of L, the effect of suppressing the azimuth detection error can be obtained by providing the blocking portion 11. In addition, it can be seen that even if L>λ / 4, no further suppression effect can be expected by simply increasing the size of the housing 3.

[0056] Figure 8 The figure shows the average value of the back radiation power measured by changing the depth D of the choke slot 33 in the structure of the embodiment. It can be seen that the average value of the back radiation power is the smallest near D = λ / 4, that is, the effect of suppressing the azimuth detection error is the largest, and whether D is shorter or longer than λ / 4, the suppression effect is reduced.

[0057] [2. Second Embodiment]

[0058] [2-1. Differences from the first embodiment]

[0059] Since the basic structure of the second embodiment is the same as that of the first embodiment, the differences will be described below. In addition, the same reference numerals as those of the first embodiment represent the same structure, and reference is made to the previous description.

[0060] In the first embodiment, the x-axis direction is used as the azimuth detection direction. In contrast, the second embodiment is different from the first embodiment in that the y-axis direction is used as the azimuth detection direction in addition to the x-axis direction and the shape of the antenna cover 4a is partially changed.

[0061] like Fig. 9 and Fig.10 As shown in FIG. 1 , the radar device 1a of the second embodiment includes an antenna unit 2, a housing 3, and a radome 4a. Figure 4 .

[0062] In the antenna unit 2, the plurality of antenna elements 22 are arranged in the same manner as in the first embodiment. However, the antenna unit 2 can not only detect the azimuth in the x-axis direction by using the same method as in the first embodiment, but can also detect the azimuth in the y-axis direction by using an array antenna having a plurality of antenna elements 22 arranged in a row on the x-axis as a unit antenna.

[0063] The two ends of the radome 4a in the x-axis direction are Figure 4 As in the case of the first embodiment shown in the figure, the housing 3 protrudes outward from the antenna cover 4a by the housing edge 32. Fig.10 As shown, the two end portions of the antenna cover 4a in the y-axis direction are fixed in the same manner as the two end portions in the x-axis direction, with the outer wall surface of the cylindrical portion 42 of the antenna cover 4a in contact with the inner wall surface of the shell recess 31, and the shell 3 protrudes outward from the antenna cover 4a by the amount of the shell edge portion 32.

[0064] That is, in the radar device 1 a , the casing edge portion 32 is provided so as to protrude outward from the radome 4 a as a whole, and functions as the stopper portion 11 .

[0065] [2-2. Effect]

[0066] According to the second embodiment described in detail above, the effects (1a) to (1c) of the first embodiment described above are achieved, and the following effects are achieved.

[0067] (2a) According to the radar device 1a, the effect of suppressing the azimuth detection error is obtained not only in the x-axis direction but also in the y-axis direction.

[0068] [3. Third embodiment]

[0069] [3-1. Differences from the first embodiment]

[0070] Since the basic structure of the third embodiment is the same as that of the first embodiment, the differences will be described below. In addition, the same reference numerals as those of the first embodiment represent the same structure, and reference is made to the previous description.

[0071] In the third embodiment, the position at which the choke groove 33b is provided in the housing 3b is different from that in the first embodiment.

[0072] like Fig.11 and Fig.12 As shown, the radar device 1b of the third embodiment includes an antenna unit 2, a housing 3b, and a radome 4. Figure 3 .

[0073] In the housing 3 b , the choke grooves 33 b are provided along the y-axis on the front side of the blocking portion 11 , that is, the housing edge portions 32 located at both ends in the x-axis direction, instead of being provided on the housing side walls.

[0074] [3-2. Effect]

[0075] According to the third embodiment described in detail above, the effects (1a) and (1b) of the first embodiment described above are achieved, and the following effects are also achieved.

[0076] (3a) According to the radar device 1b, a part of the unnecessary waves reflected by the blocking portion 11 can be cancelled out by the choke groove 33b, and the direction detection error can be further suppressed.

[0077] [4. Fourth embodiment]

[0078] [4-1. Differences from the first embodiment]

[0079] Since the basic structure of the fourth embodiment is the same as that of the first embodiment, the differences will be described below. In addition, the same reference numerals as those of the first embodiment represent the same structure, and reference is made to the previous description.

[0080] In the fourth embodiment, the shape of the radome 4c is different from that in the first embodiment.

[0081] like Fig.13 and Fig.14 As shown, the radar device 1c of the fourth embodiment includes an antenna unit 2, a housing 3, and a radome 4c. Figure 3 .

[0082] The plate-shaped portion 41c of the antenna cover 4c facing the antenna surface 23 has inclined portions 411 near both ends in the x-axis direction (i.e., the azimuth detection direction), and the inclined portions 411 are formed so that the thickness of the plate becomes thinner as it approaches the two ends. The inclined portions 411 are formed by making the inner surface of the plate-shaped portion 41c parallel to the antenna surface 23 and inclining the outer surface, thereby changing the thickness of the plate.

[0083] [4-2. Function]

[0084] A portion of the radiation wave from the antenna unit 2 is repeatedly reflected inside the antenna cover 4c and propagates toward the two ends of the antenna cover 4c in the x-axis direction, that is, the inclined portion 411. In the inclined portion 411, the amount of unnecessary waves radiated to the outside increases compared to a portion with a constant plate thickness, and accordingly, the amount of unnecessary waves radiated from the two ends of the antenna cover 4c in the x-axis direction toward the back direction decreases.

[0085] [4-3. Effect]

[0086] According to the fourth embodiment described in detail above, the effects (1a) to (1c) of the first embodiment described above are achieved, and the following effects are also achieved.

[0087] (4a) In the radar device 1c, since unnecessary waves radiated toward the rear surface are suppressed, it is possible to further suppress the direction detection error caused by the reflected waves from the vehicle body 5.

[0088] [5. Other embodiments]

[0089] As mentioned above, although embodiment of this disclosure was described, this disclosure is not limited to the said embodiment, Various deformation|transformation can be made and it can be implemented.

[0090] (5a) In the above embodiment, the choke grooves 33 and 33b are provided at only one position of the side wall of the housing 3 or the blocking portion 11, but they may be provided at both positions. In addition, the number of choke grooves 33 and 33b is not limited to one at each end in the direction of azimuth detection, but may be provided at each end in a plurality.

[0091] (5b) Multiple functions of one component in the above-mentioned embodiment may be realized by multiple components, or one function of one component may be realized by multiple components. In addition, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. In addition, part of the structure of the above-mentioned embodiment may be omitted. In addition, at least part of the structure of the above-mentioned embodiment may be added to or replaced with the structure of other above-mentioned embodiments.

Claims

1. A radar device comprising: The antenna unit has an antenna surface, which is a surface of the antenna substrate on which one or more antennas radiating radio waves are provided; a radome formed of a material that transmits radio waves radiated from the antenna unit, the radome being arranged opposite to the antenna surface; and The housing, together with the antenna cover, forms a space for accommodating the antenna unit. The shell surrounds the antenna surface, and has a stopper at a peripheral portion of the shell in the azimuth detection direction in contact with the antenna cover, the stopper protruding outward from the antenna cover in the azimuth detection direction. In the above-mentioned azimuth detection direction, the innermost surface of the above-mentioned blocking portion is located outside the outermost surface of the above-mentioned radome, The housing is provided with a housing recess on one surface, and the housing recess is a recess for accommodating the antenna substrate. The depth of the housing recess is set to be the same as the thickness of the antenna substrate. The housing surrounds a bottom surface and side surfaces of the antenna substrate, and the antenna cover is configured to cover the antenna surface of the antenna substrate.

2. The radar device according to claim 1, wherein: With the antenna surface as a boundary, the side from which the antenna portion radiates radio waves is defined as the front side, and the side opposite to the front side is defined as the back side. The above-mentioned radome is formed of a material with a relative dielectric constant greater than 1. The blocking portion is provided at a position to block at least a part of the radar waves radiated from the peripheral edge portion of the radome toward the rear surface side.

3. The radar device according to claim 2, wherein: The blocking parts are arranged at both ends of the azimuth detection direction in the radar device.

4. The radar device according to claim 3, wherein: The normal direction of the antenna surface is set to 0°, and the antenna unit is configured to irradiate radio waves within a range of at least ±60° along the azimuth detection direction.

5. The radar device according to any one of claims 1 to 4, wherein: The length of the stopper portion protruding from the radome is set to be less than or equal to 1 / 4 of the wavelength of the radio wave transmitted and received by the antenna portion.

6. The radar device according to any one of claims 1 to 4, wherein: The above-mentioned radome has: a plate-shaped portion, arranged opposite to the antenna surface; and The cylindrical portion is arranged on the periphery of the plate-shaped portion and fixed to the shell. The plate-like portion has a thickness of 1 / 2 of the wavelength inside the radome. The wavelength within the radome is a wavelength of radio waves transmitted and received by the antenna unit within the radome.

7. The radar device according to claim 5, wherein: The above-mentioned radome has: a plate-shaped portion, arranged opposite to the antenna surface; and The cylindrical portion is arranged on the periphery of the plate-shaped portion and fixed to the shell. The plate-like portion has a thickness of 1 / 2 of the wavelength inside the radome. The wavelength within the radome is a wavelength of radio waves transmitted and received by the antenna unit within the radome.

8. The radar device according to claim 6, wherein: The plate-like portion has an inclined portion, and a thickness of the inclined portion decreases toward a peripheral edge of the plate-like portion.

9. The radar device according to claim 7, wherein: The plate-like portion has an inclined portion, and a thickness of the inclined portion decreases toward a peripheral edge of the plate-like portion.

10. The radar device according to claim 8, wherein: The inclined portion is formed such that an inner side surface facing the antenna surface is formed parallel to the antenna surface, and an outer side surface opposite to the inner side surface is inclined relative to the inner side surface.

11. The radar device according to claim 9, wherein: The inclined portion is formed such that an inner side surface facing the antenna surface is formed parallel to the antenna surface, and an outer side surface opposite to the inner side surface is inclined relative to the inner side surface.

12. The radar device according to any one of claims 1 to 4, wherein: A choke groove is formed in the blocking portion, or a choke groove is formed on a side surface of the housing having the blocking portion, and the choke groove has a depth of 1 / 4 of a wavelength of radio waves transmitted and received by the antenna portion.

13. The radar device according to claim 5, wherein: A choke groove is formed in the blocking portion, or a choke groove is formed on a side surface of the housing having the blocking portion, and the choke groove has a depth of 1 / 4 of a wavelength of radio waves transmitted and received by the antenna portion.

14. The radar device according to claim 6, wherein: A choke groove is formed in the blocking portion, or a choke groove is formed on a side surface of the housing having the blocking portion, and the choke groove has a depth of 1 / 4 of a wavelength of radio waves transmitted and received by the antenna portion.

15. The radar device according to claim 7, wherein: A choke groove is formed in the blocking portion, or a choke groove is formed on a side surface of the housing having the blocking portion, and the choke groove has a depth of 1 / 4 of a wavelength of radio waves transmitted and received by the antenna portion.

16. The radar device according to claim 8, wherein: A choke groove is formed in the blocking portion, or a choke groove is formed on a side surface of the housing having the blocking portion, and the choke groove has a depth of 1 / 4 of a wavelength of radio waves transmitted and received by the antenna portion.

17. The radar device according to claim 9, wherein: A choke groove is formed in the blocking portion, or a choke groove is formed on a side surface of the housing having the blocking portion, and the choke groove has a depth of 1 / 4 of a wavelength of radio waves transmitted and received by the antenna portion.

18. The radar device according to claim 10, wherein: A choke groove is formed in the blocking portion, or a choke groove is formed on a side surface of the housing having the blocking portion, and the choke groove has a depth of 1 / 4 of a wavelength of radio waves transmitted and received by the antenna portion.

19. The radar device according to claim 11, wherein: A choke groove is formed in the blocking portion, or a choke groove is formed on a side surface of the housing having the blocking portion, and the choke groove has a depth of 1 / 4 of a wavelength of radio waves transmitted and received by the antenna portion.

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