Lens, antenna device, communication apparatus, and mobile body

Abstract

To provide a lens adopted for an antenna device with a simple structure that a communication quality deterioration and a communication interruption are hardly generated in the case where it is adopted to a communication between mobile bodies.SOLUTION: A lens comprises a lens main body of a dielectric body, including a penetration hole in which a horizontal inner surface non-directional antenna is arranged, and includes a convex-like outer curvature of a rotation symmetry to a circumference of a center shaft of the penetration hole, and formed by a whole or a part of a peripheral direction of the rotation symmetry. An inner surface faced to the penetration hole of the lens main body is separated from the center shaft of the penetration hole by λ / 2π or more, and a distance of a separation may be not equal to a focal distance F in a radial direction of the lens main body. The outer curvature surface of the lens main body may be an aspherical surface that is determined on the basis of a relative dielectric constant of the dielectric body, a distance from the focal distance in the radial direction of the lens main body, and an end edge from a shaft direction center of the inner surface of the lens main body. The focal distance F in the radial direction of the lens main body may be a double of λ / 2π (λ is a wavelength of an electric wave). In the lens main body, a reflection member may be arranged in a partial omission part one part of the peripheral direction of the rotational symmetry is omitted.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a lens suitable for vehicle-to-vehicle communication using radio waves such as microwaves, millimeter waves, and submillimeter waves, as well as an antenna device, a communication device, and a mobile object that are equipped with the lens. [Background technology]

[0002] Conventionally, a communication device having an antenna device that can be mounted on a moving body such as a vehicle that performs inter-moving body communication such as inter-vehicle communication is known. For example, cited reference 1 discloses a communication device that is provided on a first moving body (vehicle) that can move along a moving path and performs inter-moving body communication (inter-vehicle communication) with another second moving body (vehicle) when the first moving body moves along the moving path. According to this communication device, a directional beam toward the second moving body is formed by a directional antenna, and when the second moving body goes out of the range of the directional beam and communication disconnection is predicted, tracking of the directional beam toward the second moving body is started, so that inter-moving body communication can be continued even when changing lanes on the moving path, turning right or left at an intersection, driving around a curve, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-113227 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a conventional communication device for performing communication between mobile objects, such as inter-vehicle communication, there is a demand for an antenna device with a simple configuration that is less susceptible to deterioration in communication quality or interruption of communication when applied to inter-mobile communication. [Means for solving the problem]

[0005] A lens according to one aspect of the present invention is a lens for microwave, millimeter wave, or submillimeter wave radio waves. This lens includes a dielectric lens body having a through hole in which an antenna that is omnidirectional in a horizontal plane is disposed, and which is made of a rotationally symmetric body having a convex outer curved surface that is rotationally symmetric about the central axis of the through hole, in the entirety or part of the circumferential direction.

[0006] In the lens, an inner surface of the lens body facing the through hole may be separated from the central axis of the through hole by λ / 2π (λ: wavelength of radio waves) or more, and the separation distance may be equal to a focal length F in a radial direction of the lens body. Here, the radial direction of the lens body is a direction along the radius or diameter of the lens body that passes through the center of the lens body and is perpendicular to the central axis.

[0007] In any of the above lenses, the outer curved surface of the lens body has a relative dielectric constant ε r The lens may have an aspheric surface determined based on a focal length F in a radial direction of the lens body and a distance R from the center to an edge of the inner surface of the lens body in a direction along the rotation axis.

[0008] In any of the lenses described above, a focal length F in a radial direction of the lens body may be an integer multiple of λ / 2 (λ: wavelength of radio waves).

[0009] In any of the lenses described above, the lens body may have a shape in which a portion of the rotationally symmetric body in the circumferential direction is missing. Also, a reflective member that reflects the radio waves may be disposed in a missing portion in the circumferential direction of the lens body.

[0010] In any of the lenses described above, the rotationally symmetric body may have a shape with one rotational symmetry around the central axis of the through hole. The rotationally symmetric body may have a plurality (n) rotationally symmetric shapes around the central axis of the through hole. The rotationally symmetric body may have a rotationally symmetric shape formed discretely at predetermined angles (at predetermined angle steps) around the central axis of the through hole. For example, the rotationally symmetric body may have a two- or three-rotationally symmetric shape formed discretely at 180 degrees or 120 degrees around the central axis of the through hole. The rotationally symmetric body may have a 36-, 18-, or 21-rotationally symmetric shape formed discretely at 10 degrees, 20 degrees, or 30 degrees around the central axis of the through hole.

[0011] An antenna device according to another aspect of the present invention includes any one of the lenses described above, and an omnidirectional antenna in a horizontal plane disposed in a through hole of the lens.

[0012] A communication device according to still another aspect of the present invention includes the antenna device and a wireless communication unit connected to the antenna of the antenna device.

[0013] A moving body according to still another aspect of the present invention includes the communication device and performs inter-moving body communication with another moving body located at least one of the front and rear in the direction of movement.

[0014] In the mobile body, the antenna device may have a directional beam with a beam width of 150 degrees or more and 180 degrees or less in mobile-to-mobile communication with the other mobile body.

[0015] The moving body may include a plurality of the antenna devices at least on either the front or rear side in the moving direction of the moving body, and the same radio wave may be transmitted or received via the plurality of antenna devices. Effect of the Invention

[0016] According to the present invention, it is possible to provide an antenna device having a simple configuration that is less susceptible to deterioration of communication quality or interruption of communication when applied to mobile communication. [Brief description of the drawings]

[0017] [Figure 1] Fig. 1(a) is a diagram showing an example of the horizontal plane directivity characteristic of a dipole antenna applicable to the antenna device according to the embodiment, and Fig. 1(b) is a diagram showing an example of the vertical plane directivity characteristic of the same dipole antenna. [Diagram 2] FIG. 2 is a diagram showing an example of the horizontal plane directivity characteristic of a half-wave dipole antenna. [Diagram 3] FIG. 3 is a front view showing an example of an antenna device in which a half-wavelength dipole antenna and a single aspherical lens are combined. [Figure 4] FIG. 4 is a diagram showing an example of the directional characteristics in the horizontal plane of the antenna device of FIG. [Diagram 5] 5(a) and 5(b) are diagrams illustrating problems that arise when a plurality of vehicles, each equipped with an antenna device having beam directivity, travel while performing inter-vehicle communication. [Figure 6] FIG. 6 is a diagram showing the positional relationship between an aspheric lens as a basic shape element used in designing the shape of a lens constituting the antenna device of the embodiment and a half-wavelength dipole antenna. [Figure 7] Fig. 7(a) is a perspective view of the lens of the first embodiment as seen obliquely from the side, and Fig. 7(b) is a perspective view of the lens of the first embodiment as seen obliquely from above. [Figure 8] FIG. 8 is a diagram showing an example of the directional characteristics in a horizontal plane of the lens according to the first embodiment. [Figure 9] FIG. 9 is a perspective view of the lens of the second embodiment as viewed obliquely from above. [Figure 10] FIG. 10 is a diagram showing an example of the directional characteristics in a horizontal plane of the lens according to the second embodiment. [Figure 11] FIG. 11 is a perspective view of the lens of the third embodiment as viewed obliquely from above. [Figure 12] FIG. 12 is a diagram showing an example of the directional characteristics in a horizontal plane of the lens according to the third embodiment. [Figure 13]FIG. 13 is a perspective view of the lens of the fourth embodiment as viewed obliquely from above. [Figure 14] FIG. 14 is a diagram showing an example of the directional characteristics in a horizontal plane of the lens according to the fourth embodiment. [Figure 15] Fig. 15(a) is a plan view of the lens of the fifth embodiment, Fig. 15(b) is a perspective view of an antenna device having the lens of the fifth embodiment, as viewed obliquely from the front, and Fig. 15(c) is a perspective view of an antenna device having the lens of the fifth embodiment, as viewed obliquely from the left side. [Figure 16] Fig. 16(a) is a plan view of the lens of the sixth embodiment, Fig. 16(b) is a perspective view showing the front and plan of the lens of the sixth embodiment, and Fig. 16(c) is a perspective view of an antenna device having the lens of the sixth embodiment as seen obliquely from below. [Figure 17] FIG. 17 is a diagram showing an example of how the antenna device according to the embodiment is attached to a vehicle. [Figure 18] FIG. 18 is a front view of the lens of the seventh embodiment. [Figure 19] FIG. 19 is a rear view of the lens of the seventh embodiment. [Figure 20] FIG. 20 is a left side view of the lens of the seventh embodiment. [Figure 21] FIG. 21 is a right side view of the lens of the seventh embodiment. [Figure 22] FIG. 22 is a plan view of the lens of the seventh embodiment. [Diagram 23] FIG. 23 is a bottom view of the lens of the seventh embodiment. [Figure 24] FIG. 24 is a front view of the lens of the eighth embodiment. [Diagram 25] FIG. 25 is a rear view of the lens of the eighth embodiment. [Figure 26] FIG. 26 is a left side view of the lens of the eighth embodiment. [Figure 27] FIG. 27 is a right side view of the lens of the eighth embodiment. [Figure 28] FIG. 28 is a plan view of the lens of the eighth embodiment. [Figure 29]FIG. 29 is a bottom view of the lens of the eighth embodiment. [Diagram 30] FIG. 30 is a front view of the lens of the ninth embodiment. [Diagram 31] FIG. 31 is a rear view of the lens of the ninth embodiment. [Diagram 32] FIG. 32 is a left side view of the lens of the ninth embodiment. [Diagram 33] FIG. 33 is a right side view of the lens of the ninth embodiment. [Diagram 34] FIG. 34 is a plan view of the lens of the ninth embodiment. [Diagram 35] FIG. 35 is a bottom view of the lens of the ninth embodiment. [Diagram 36] FIG. 36 is a front view of the lens of the tenth embodiment. [Figure 37] FIG. 37 is a rear view of the lens of the tenth embodiment. [Figure 38] FIG. 38 is a left side view of the lens of the tenth embodiment. [Figure 39] FIG. 39 is a right side view of the lens of the tenth embodiment. [Diagram 40] FIG. 40 is a plan view of the lens of the tenth embodiment. [Diagram 41] FIG. 41 is a bottom view of the lens of the tenth embodiment. [Diagram 42] FIG. 42 is a front view of the lens of the eleventh embodiment. [Diagram 43] FIG. 43 is a rear view of the lens of the eleventh embodiment. [Diagram 44] FIG. 44 is a left side view of the lens of the eleventh embodiment. [Diagram 45] FIG. 45 is a right side view of the lens of the eleventh embodiment. [Diagram 46] FIG. 46 is a plan view of the lens of the eleventh embodiment. [Figure 47] FIG. 47 is a bottom view of the lens of the eleventh embodiment. [Figure 48] FIG. 48 is a front view of the lens of the twelfth embodiment. [Figure 49]FIG. 49 is a rear view of the lens of the twelfth embodiment. [Figure 50] FIG. 50 is a left side view of the lens of the twelfth embodiment. [Figure 51] FIG. 51 is a right side view of the lens of the twelfth embodiment. [Figure 52] FIG. 52 is a plan view of the lens of the twelfth embodiment. [Figure 53] FIG. 53 is a bottom view of the lens of the twelfth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The devices according to the embodiments described in this specification are an antenna device suitable for microwave, millimeter wave, and submillimeter wave radio waves, a communication device including the antenna device and a wireless communication unit, and a mobile body including the communication device. The antenna device according to the embodiments includes a lens for microwave, millimeter wave, or submillimeter wave radio waves. The lens has a through hole in which an antenna that is omnidirectional in a horizontal plane is disposed, and has a dielectric lens body consisting of the whole or part of a circumferential direction of a rotationally symmetric body having a convex outer curved surface that is rotationally symmetric around the central axis of the through hole. This makes it possible to realize an antenna device with a simple configuration that is less likely to cause communication quality deterioration or communication interruption when applied to mobile-to-mobile communication using microwave, millimeter wave, or submillimeter wave radio waves. In particular, the antenna device according to the present embodiment is an antenna device suitable for realizing vehicle-to-vehicle communication using fifth-generation or later-generation mobile communication.

[0019] In this embodiment, the moving body is a vehicle that travels on a road that is a ground moving path, but there is no particular restriction on the type of moving body and the type of moving path. For example, the vehicle may be an automobile, a truck, a bus, a motorcycle, etc. The vehicle may be a vehicle with an automatic driving function, or a manually driven vehicle without an automatic driving function. In addition, the moving body that is the object of collision possibility determination may be a moving body such as an aircraft that can fly and move along a moving path in the sky at a predetermined altitude, in addition to a ground vehicle. In addition, the moving body may be an underground moving body that moves along an underground moving path, an above-water moving body such as a ship that can move along a moving path on water (e.g., on the sea), or an underwater moving body such as a submersible robot that moves along a moving path underwater (e.g., under the sea).

[0020] The vehicle of the present embodiment may be an electric vehicle, a fuel cell vehicle, or a hybrid vehicle having both an internal combustion engine and an electric motor. In addition, when the vehicle has multiple seats for occupants or passengers, the vehicle may be a vehicle in which the frontmost and leftmost seat is not the driver's seat. In other words, the vehicle may be a vehicle in which only the frontmost and rightmost seat is the driver's seat, or an autonomous vehicle that does not have a driver's seat in the first place.

[0021] In addition, the configuration and communication method of the mobile communication network in this embodiment are not limited to those conforming to a specific generation standard. The configuration and communication method of the mobile communication network in this embodiment may conform to, for example, LTE, LTE-Advanced, the fifth generation, or a later generation standard.

[0022] FIG. 1(a) is a diagram showing an example of a directional characteristic 100H in a horizontal plane of a dipole antenna applicable to the antenna device according to the embodiment, and FIG. 1(b) is a diagram showing an example of a directional characteristic 100V in a vertical plane of the same dipole antenna. FIG. 2 is a diagram showing an example of a directional characteristic 100H in a horizontal plane of a half-wavelength dipole antenna. The directional characteristic in the horizontal plane of FIG. 2 is obtained by electromagnetic field simulation using a computer based on the FDTD (Finite Difference Time Domain) method. As an antenna for communication between mobile objects such as vehicle-to-vehicle communication, ideally, an antenna that has directivity in the vertical plane as shown in FIG. 1(b) and is completely omnidirectional in the horizontal plane as shown in FIG. 1(a) and FIG. 2 is desirable. Such directivity is close to the characteristics of a colinear antenna.

[0023] FIG. 3 is a front view showing an example of an antenna device 100' in which a half-wave dipole antenna 10' and a single aspheric lens 20 are combined. FIG. 4 is a diagram showing an example of a horizontal plane directional characteristic 101H of the antenna device 100' of FIG. 3. Note that black (single color) in FIG. 3 is the color of the background (similarly in FIG. 6, FIG. 7(a), FIG. 7(b), FIG. 9, FIG. 11, and FIG. 13 described later). The aspheric lens 20 in FIG. 3 is a dielectric lens made of a dielectric material such as fluororesin (e.g., Teflon (registered trademark)), and can be used for the purpose of increasing the gain in the antenna directivity (in the illustrated example, the gain is increased from about 2.5 dBi to about 6 dBi) or changing the direction of the beam, as shown in FIG. 4, which shows a downward beam-like horizontal plane directional characteristic 101H.

[0024] 5(a) and 5(b) are explanatory diagrams of the problem when a plurality of vehicles (mobiles) 41, 42 each equipped with an antenna device having beam directivity travel while performing vehicle-to-vehicle communication. In Fig. 5, the leading vehicle 41 is equipped with an antenna device having a rearward in-horizontal plane directivity characteristic 141HR and a lateral in-horizontal plane directivity characteristic 141HS based on the traveling direction. The following vehicle 42 is equipped with an antenna device having a forward in-horizontal plane directivity characteristic 141HF based on the traveling rear.

[0025] On the straight road (travel route) shown in Figure 5 (a), vehicle-to-vehicle communication can be carried out with the rearward horizontal directional characteristic 141HR of the leading vehicle 41 and the forward horizontal directional characteristic 141HF of the following vehicle 42 almost facing each other, making it less likely that deterioration of communication quality or connection interruptions will occur.

[0026] However, on a curved road (travel route) as shown in Fig. 5(b), the backward horizontal directional characteristic 141HR and the sideward horizontal directional characteristic 141HS of the preceding vehicle 41 do not face the forward horizontal directional characteristic 141HF of the following vehicle 42, which may cause deterioration in communication quality or disconnection of the inter-vehicle communication. In particular, when traveling around a curve while performing inter-vehicle communication with a wide inter-vehicle distance, if the gain decreases due to the null of the antenna's horizontal directional characteristic, communication quality is likely to deteriorate or connection is likely to be disconnected.

[0027] As one of the countermeasures against the above-mentioned deterioration of communication quality and disconnection, beam tracking as described in the above-mentioned Patent Document 1 can be considered, but a device for controlling the beam is required. Also, a co-linear antenna can be considered to increase antenna gain while making it omnidirectional in the horizontal plane, but to obtain a high gain such as 10 dBi, the number of element stages becomes large. Therefore, for example, in a series-type co-linear antenna, wavelength errors of several mm accumulate and the desired gain cannot be obtained, and in a parallel-type co-linear antenna, a distribution structure for parallel power supply and a support structure for vertical arrangement are required, making the structure complicated and difficult to manufacture.

[0028] Therefore, in this embodiment, as exemplified below, by combining a horizontal plane non-directional (omni) antenna with a lens having a specific shape described below, an antenna device 100 with a simple configuration is provided that is less susceptible to communication quality degradation and communication interruptions when applied to vehicle-to-vehicle communication (mobile-to-mobile communication).

[0029] 6 is a diagram showing the positional relationship between an aspherical lens 20 as a basic shape element used in designing the shape of a lens constituting an antenna device of an embodiment, and an antenna 10 that is omnidirectional in a horizontal plane. The lenses of the embodiments exemplified below can be designed using, for example, the shape of the aspherical lens 20 shown in FIG. 6 as a basic shape element.

[0030] The aspheric lens 20 is made of a fluororesin such as PTFE (polytetrafluoroethylene) (e.g., r 6, the lens is made of a dielectric material (Teflon (registered trademark)) having a thickness of 2.1 mm, and has an antenna-facing surface 201 on the antenna side and an outwardly curved surface 202. In FIG. 6, when the wavelength of the target radio wave is λ, the distance between the antenna-facing surface 201 of the aspherical lens 20 and the horizontal plane omnidirectional antenna 10 is equal to the focal length F (=λ / 2) of the aspherical lens 20. In addition, the radius (lens radius) R of the circular antenna-facing surface 201 on the outer periphery of the aspherical lens 20 is equal to 5λ / 2. This radius (lens radius) R corresponds to the distance from the center to the edge in the direction along the rotation axis of the inner surface facing the through hole in the lens body of the lens that is finally formed.

[0031] Although the illustrated antenna facing surface 201 is a flat surface, it may be a curved surface. Also, the illustrated curved surface 202 is an aspheric surface, but it may be a part of a sphere. Also, the antenna 10 in Fig. 6, which is omnidirectional in the horizontal plane, is a half-wave dipole antenna, but it does not have to be a half-wave dipole antenna as long as it has omnidirectional characteristics in the horizontal plane.

[0032] An integral structure is obtained by rotating the aspheric lens 20 continuously or in predetermined angular steps around the position of the horizontal omnidirectional antenna 10 in Fig. 6, and the surface of the integral structure gives a disk-shaped lens shape consisting of a rotationally symmetric body. This lens has a through hole in which the horizontal omnidirectional antenna 10 is placed, and is provided with a lens body consisting of the whole or part of the circumferential direction of a rotationally symmetric body having a rotationally symmetric convex outer curved surface around the central axis of the through hole (the radiation center of the antenna).

[0033] The lens may be spaced λ / 2π or more away from the radiation center of the horizontal plane omnidirectional (omni) antenna 10, with the distance being the focal length F of the lens. That is, in the lens, the inner surface facing the through hole of the lens body may be spaced λ / 2π or more away from the central axis of the through hole, with the distance being equal to the focal length F in the radial direction of the lens body. By combining lenses having such shapes, horizontal omnidirectionality with high antenna gain can be obtained with the lenses alone, and deterioration of communication quality and occurrence of connection interruptions can be suppressed.

[0034] The outer curved surface of the lens may be an aspheric surface that is designed and determined by a ray tracing method based on the relative dielectric constant εr, focal length F, and lens radius R of the basic shape element (see FIG. 6). The outer curved surface of the lens that is an aspheric surface determined in this manner can correct the deviation of the focal position of the lens (spherical aberration).

[0035] In addition, the focal length F may be an integer multiple of λ / 2 so that the reflected wave and the direct wave when entering the lens are in phase. This makes it possible to effectively utilize the power of the reflected wave when entering the lens and improve the antenna gain.

[0036] The lens body may have an arc shape consisting of a part of the circumference of a rotationally symmetric body obtained by rotating the aspheric lens 20 around the position of the horizontal plane omnidirectional antenna 10 in Fig. 6, and a part of the circumference of the rotationally symmetric body (a partially missing part of the lens body) may be replaced with a reflecting member that reflects the target radio wave. This makes it possible to suppress unnecessary radiation and, as described above, to effectively utilize power and improve antenna gain.

[0037] FIG. 7(a) is a perspective view of the lens 21 of the first embodiment seen from a side oblique position, and FIG. 7(b) is a perspective view of the lens 21 of the first embodiment seen from a top oblique position. FIG. 7(a) and FIG. 7(b) are examples of the lens 21 formed based on an integral structure (36 rotationally symmetric body) obtained by rotating the aspheric lens 20 as a basic shape element one revolution (360 degrees) at a predetermined angle (10 degrees in the example of FIG. 7) step around the central axis Z0 in the Z-axis direction passing through the position of the antenna 10, which is omnidirectional in the horizontal plane, in FIG. 6. The surface of this integral structure gives the shape of the disk-shaped lens 21 consisting of the entire rotationally symmetric body. The lens 21 has a through hole 210 in which the antenna 10, which is omnidirectional in the horizontal plane, is disposed, and includes a lens body 211 consisting of the entire circumferential direction of the rotationally symmetric body having a convex outer curved surface that is rotationally symmetric around the central axis Z0 (radiation center of the antenna) of the through hole 210.

[0038] Lens 21 can be formed by a three-dimensional printer using a dielectric material such as fluororesin (e.g., Teflon (registered trademark)) such as PTFE (polytetrafluoroethylene). Lenses in other embodiments described below can be formed in a similar manner. Note that the material of lens 21 may be a dielectric material other than fluororesin as long as it has a predetermined relative dielectric constant and transmittance for the target radio waves (the same applies to lenses in other embodiments described below).

[0039] Fig. 8 is a diagram showing an example of the horizontal plane directional characteristics of the lens 21 of the first embodiment. As shown in Fig. 8, by combining the antenna 10, which is omnidirectional in the horizontal plane, with the lens 21 of Fig. 7(a) and Fig. 7(b), it is possible to provide an antenna device 100, which is omnidirectional in the horizontal plane and has a high antenna gain (10 dBi in the illustrated example).

[0040] The shape of the lens 21 in Fig. 7(a) and Fig. 7(b) and the antenna directivity characteristic in Fig. 8 can be obtained, for example, by computer-based electromagnetic field simulation using the FDTD (Finite Difference Time Domain) method. The same applies to the lenses of other embodiments described below.

[0041] 9 is a perspective view of the lens 22 of the second embodiment seen from an oblique direction above. FIG. 9 shows an example of the lens 22 formed based on an integral structure (a part of a 36-rotationally symmetric body in the circumferential direction) obtained by rotating the aspheric lens 20 5 / 6 revolutions (300 degrees) at a predetermined angle (10 degrees in the example of FIG. 9) step around the central axis Z0 in the Z-axis direction passing through the position of the antenna 10, which is omnidirectional in the horizontal plane, in FIG. 6. The surface of this integral structure gives the shape of the disk-shaped lens 22, which is a part of a rotationally symmetric body. The lens 22 has a through hole 220 in which the antenna 10, which is omnidirectional in the horizontal plane, is disposed, and includes a lens body 221, which is a part of a rotationally symmetric body in the circumferential direction, having a convex outer curved surface that is rotationally symmetric around the central axis Z0 of the through hole 220 (the radiation center of the antenna). In addition, an arc-shaped reflector 222 is provided as a reflective member at a position on the inner surface of the lens body 221 within an angular range of 1 / 6 of a revolution (360 degrees) when the aspheric lens 20 is not rotated (a partially missing portion of the lens body).

[0042] Fig. 10 is a diagram showing an example of the horizontal plane directivity characteristic of the lens 22 of the second embodiment. As shown in Fig. 10, by combining the horizontal plane omnidirectional antenna 10, the lens 22 of Fig. 9, and an arc-shaped reflector 222 as a reflecting member, it is possible to provide the horizontal plane omnidirectional antenna device 100 with a high antenna gain (10 dBi to 13.5 dBi in the illustrated example).

[0043] Fig. 11 is a perspective view of the lens 23 of the third embodiment, seen from an oblique direction above. Fig. 11 is an example of the lens 23 formed based on an integrated structure obtained by continuously rotating the aspheric lens 20 one revolution (360 degrees) around the central axis Z0 in the Z-axis direction passing through the position of the antenna 10, which is omnidirectional in the horizontal plane, in Fig. 6. The surface of this integrated structure gives the shape of the disk-shaped lens 23, which is made up of the entire rotationally symmetric body. The lens 23 has a through hole 220 in which the antenna 10, which is omnidirectional in the horizontal plane, is disposed, and includes a lens body 231, which is made up of the entire circumferential direction of a rotationally symmetric body having a convex outer curved surface that is rotationally symmetric around the central axis (radiation center of the antenna) Z0 of the through hole 230.

[0044] Fig. 12 is a diagram showing an example of the horizontal plane directional characteristics of the lens 23 of the third embodiment. As shown in Fig. 12, by combining the antenna 10, which is omnidirectional in the horizontal plane, with the lens 22 of Fig. 11, it is possible to provide an antenna device 100, which is omnidirectional in the horizontal plane and has a high antenna gain (10 dBi in the illustrated example).

[0045] FIG. 13 is a perspective view of the lens 24 of the fourth embodiment, seen from an oblique direction above. FIG. 13 is an example of the lens 24 formed based on an integrated structure obtained by continuously rotating the aspheric lens 20 5 / 6 revolutions (300 degrees) around the central axis Z0 in the Z-axis direction passing through the position of the antenna 10, which is omnidirectional in the horizontal plane, in FIG. 6. The surface of this integrated structure obtains the shape of the disk-shaped lens 24, which is a part of a rotationally symmetric body. The lens 24 has a through hole 240 in which the antenna 10, which is omnidirectional in the horizontal plane, is disposed, and includes a lens body 241, which is a part of a rotationally symmetric body in the circumferential direction, having a convex outer curved surface that is rotationally symmetric around the central axis (radiation center of the antenna) Z0 of the through hole 240. In addition, an arc-shaped reflector 242 is provided as a reflecting member at a position on the inner peripheral surface of the lens body 241 within an angular range of 1 / 6 revolutions (360 degrees) where the aspheric lens 20 is not rotated.

[0046] Fig. 14 is a diagram showing an example of the horizontal plane directivity characteristic of the lens 24 of the fourth embodiment. As shown in Fig. 14, by combining the horizontal plane omnidirectional antenna 10, the lens 22 of Fig. 13, and an arc-shaped reflector 242 as a reflecting member, it is possible to provide the horizontal plane omnidirectional antenna device 100 with a high antenna gain (10 dBi to 13.5 dBi in the illustrated example).

[0047] FIG. 15(a) is a plan view of the lens 25 of the fifth embodiment. FIG. 15(a) is an example of the lens 25 formed based on an integral structure (a part of a 12-rotationally symmetric body in the circumferential direction) obtained by rotating the aspheric lens 20 by one-third of a revolution (120 degrees) at a predetermined angle (30 degrees in the example of FIG. 15) step with the focal length F being long and the antenna-facing surface 201 being spaced from the antenna radiation center, centered on the central axis Z0 in the Z-axis direction passing through the position of the antenna 10 in the horizontal plane omnidirectional in FIG. 6. The surface of this integral structure gives the shape of the lens 25 in the arc shape made of a part of the rotationally symmetric body. The lens 25 has a through hole 250 in which the antenna 10 in the horizontal plane omnidirectional is disposed, and includes a lens body 251 made of a part of a rotationally symmetric body in the circumferential direction having a convex outer curved surface that is rotationally symmetric around the central axis Z0 of the through hole 250 (the antenna radiation center).

[0048] Fig. 15(b) is a perspective view of the antenna device 100 having the lens 25 of the fifth embodiment, as viewed obliquely from the front. Fig. 15(c) is a perspective view of the antenna device 100 having the lens 25 of the fifth embodiment, as viewed obliquely from the left side. As shown in Figs. 15(b) and 15(c), the lens 25 has a through-hole 250 which is a relatively large antenna installation space, so that a large-sized antenna unit 11 having an antenna that is omnidirectional in the horizontal plane can be easily installed.

[0049] FIG. 16(a) is a plan view of the lens 26 of the sixth embodiment. FIG. 16(b) is a perspective view showing the front and plan views of the lens 26 of the sixth embodiment. FIG. 16(a) and FIG. 16(b) are examples of the lens 26 formed based on an integrated structure obtained by continuously rotating the aspheric lens 20 one revolution (360 degrees) around the central axis Z0 in the Z-axis direction passing through the position of the antenna 10 in the horizontal plane omnidirectional in FIG. 6, with the focal length F being long and the antenna-facing surface 201 being spaced from the antenna radiation center. The surface of this integrated structure obtains the shape of the ring-shaped lens 26 consisting of the entire rotationally symmetric body. The lens 26 has a through hole 260 in which the antenna 10 in the horizontal plane omnidirectional is disposed, and includes a lens body 261 consisting of the entire circumferential direction of a rotationally symmetric body having a convex outer curved surface that is rotationally symmetric around the central axis Z0 of the through hole 260 (the antenna radiation center).

[0050] Fig. 16(c) is a perspective view of the antenna device 100 having the lens 26 of the sixth embodiment, viewed from a diagonal downward direction. As shown in Fig. 16(c), the lens 26 has a through hole 260 which is a relatively large antenna installation space, so that a large-sized antenna unit 11 having an antenna that is omnidirectional in the horizontal plane can be easily installed.

[0051] FIG. 17 is a diagram showing an example of mounting the antenna device 100 of the embodiment to a vehicle 40. In the example of FIG. 17, a stay member 403 for mounting an auxiliary mirror is provided on an outer frame 402 located on the side of a windshield 401 of a vehicle (large vehicle) as a moving body, and the antenna device 100 is mounted on the stay member 403. In FIG. 17, a plurality of (for example, two sets of) antenna devices 100 may be mounted on the stay member 403 in order to obtain an antenna diversity effect in inter-vehicle communication. In addition, a moving body such as a vehicle equipped with the antenna device 100 of the embodiment and a communication device having a wireless communication unit may perform inter-vehicle communication with another moving body such as a vehicle located at least in front or behind the moving body. The antenna device of the moving body may have a directional beam with a beam width of 150 degrees or more and 180 degrees or less in a horizontal plane in inter-vehicle communication with another moving body. In addition, a moving body such as a vehicle may be provided with multiple antenna devices at least on either the front or rear of the moving direction of the moving body, and may transmit or receive the same radio waves via the multiple antenna devices, for example, to obtain a diversity effect.

[0052] 18 to 23 are respectively a front view, a rear view, a left side view, a right side view, a plan view, and a bottom view of the lens of the seventh embodiment. Note that the black (single color) in each of the lenses in Figs. 18 to 23 is the color of the background. Also, the shading shown on the lens surface in each of Figs. 18 to 23 is intended to specify the three-dimensional shape.

[0053] 18 to 23 are lenses formed based on an integrated structure (part of a 12-rotationally symmetric body) obtained by rotating an aspheric lens 20 (see FIG. 6) as a basic form element by one-third of a revolution (120 degrees) in 30-degree steps around the central axis in the Z-axis direction. This lens has a through hole in which an antenna that is omnidirectional in the horizontal plane is disposed, and is provided with an arc-shaped lens body consisting of a part in the circumferential direction of a rotationally symmetric body having a convex outer curved surface that is rotationally symmetric around the central axis of the through hole (the radiation center of the antenna).

[0054] 24 to 29 are respectively a front view, a rear view, a left side view, a right side view, a plan view, and a bottom view of the lens of the eighth embodiment. Note that black (single color) in all of Figs. 24 to 29 is the color of the background. Also, the shading shown on the lens surface in Figs. 24 to 29 is intended to specify the three-dimensional shape.

[0055] 24 to 29 are lenses formed based on an integral structure (part of a 12-rotationally symmetric body) obtained by rotating an aspheric lens 20 (see FIG. 6) as a basic form element by one-third of a revolution (120 degrees) in 30-degree steps around the central axis in the Z-axis direction. This lens has a through hole in which an omnidirectional antenna in a horizontal plane is disposed, and includes an arc-shaped lens body consisting of a part in the circumferential direction of a rotationally symmetric body having a convex outer curved surface that is rotationally symmetric around the central axis of the through hole (the radiation center of the antenna), and an upper disk installed on the upper surface of the lens body.

[0056] 30 to 35 are respectively a front view, a rear view, a left side view, a right side view, a plan view, and a bottom view of the lens of the ninth embodiment. Note that the black (single color) in all of Figs. 30 to 35 is the color of the background. Also, the shading shown on the lens surface in Figs. 30 to 35 is intended to specify the three-dimensional shape.

[0057] 30 to 35 are lenses formed based on an integrated structure (a part of the circumferential direction of a rotationally symmetric body 36) obtained by rotating an aspheric lens 20 (see FIG. 6) as a basic form element by one-third of a revolution (120 degrees) in 10-degree steps around the central axis in the Z-axis direction. This lens has a through hole in which an antenna that is omnidirectional in the horizontal plane is disposed, and is provided with an arc-shaped lens body consisting of a part of the circumferential direction of a rotationally symmetric body having a convex outer curved surface that is rotationally symmetric around the central axis of the through hole (the radiation center of the antenna).

[0058] 36 to 41 are respectively a front view, a rear view, a left side view, a right side view, a plan view, and a bottom view of the lens of the tenth embodiment. Note that black (single color) in all of Figs. 36 to 41 is the color of the background. Also, the shading shown on the lens surface in Figs. 36 to 41 is intended to specify the three-dimensional shape.

[0059] 36 to 41 are lenses formed based on an integrated structure (a part of the circumferential direction of a rotationally symmetric body 36) obtained by rotating an aspheric lens 20 (see FIG. 6) as a basic form element by one-third of a revolution (120 degrees) in 10-degree steps around the central axis in the Z-axis direction. This lens has a through hole in which an antenna that is omnidirectional in the horizontal plane is disposed, and includes an arc-shaped lens body consisting of a part of the circumferential direction of a rotationally symmetric body having a convex outer curved surface that is rotationally symmetric around the central axis of the through hole (the radiation center of the antenna), and an upper disk installed on the upper surface of the lens body.

[0060] 42 to 47 are respectively a front view, a rear view, a left side view, a right side view, a plan view, and a bottom view of the lens of the eleventh embodiment. Note that the black (single color) in all of Figs. 42 to 47 is the color of the background. Also, the shading shown on the lens surface in Figs. 42 to 47 is intended to specify the three-dimensional shape.

[0061] 42 to 47 are lenses formed based on an integral structure (a circumferential portion of a rotationally symmetric body (continuously rotating body)) obtained by continuously rotating an aspheric lens 20 (see FIG. 6) as a basic form element through one-third of a revolution (120 degrees) around the central axis in the Z-axis direction. This lens has a through hole in which an antenna that is omnidirectional within a horizontal plane is disposed, and is provided with an arc-shaped lens body consisting of a circumferential portion of a rotationally symmetric body having a convex outer curved surface that is rotationally symmetric around the central axis of the through hole (the radiation center of the antenna).

[0062] 48 to 53 are respectively a front view, a rear view, a left side view, a right side view, a plan view, and a bottom view of the lens of the twelfth embodiment. Note that the black (single color) in all of Figs. 48 to 53 is the color of the background. Also, the shading shown on the lens surface in Figs. 48 to 53 is intended to specify the three-dimensional shape.

[0063] 48 to 53 are lenses formed based on an integral structure (a circumferential portion of a rotationally symmetric body (continuously rotating body)) obtained by continuously rotating an aspheric lens 20 (see FIG. 6) as a basic form element through one-third of a revolution (120 degrees) around the central axis in the Z-axis direction. This lens has a through hole in which an antenna that is omnidirectional in a horizontal plane is disposed, and includes an arc-shaped lens body consisting of a circumferential portion of a rotationally symmetric body having a convex outer curved surface that is rotationally symmetric around the central axis of the through hole (the radiation center of the antenna), and an upper disk installed on the upper surface of the lens body.

[0064] As described above, according to this embodiment, it is possible to provide the antenna device 100 having a simple configuration that is less susceptible to deterioration in communication quality or communication interruption when applied to communication between mobile objects, such as vehicle-to-vehicle communication.

[0065] In addition, the present invention can provide mobile communications, such as vehicle-to-vehicle communications, that are less susceptible to degradation in communication quality or interruptions over the long term, thereby contributing to the achievement of Goal 9 of the Sustainable Development Goals (SDGs), which is to "build infrastructure, promote industry, innovation and foster innovation."

[0066] Moreover, the description of the embodiments disclosed herein is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. [Explanation of symbols]

[0067] 10: Antenna 11: Antenna unit 20: Aspheric lens 21~26: Lens 40: Vehicle 100: Antenna device 201: Antenna facing surface 202: Curved surface 210: Through hole 211: Lens body 220:Through hole 221: Lens body 222:Reflector 230:Through hole 231: Lens body 240:Through hole 241: Lens body 242:Reflector 250:Through hole 251: Lens body 260:Through hole 261: Lens body 401: Windshield 402: Outer frame 403: Stay member

Claims

1. A lens for microwave, millimeter wave or submillimeter wave radio waves, The lens body is made of a dielectric material and has a through hole in which a horizontal plane omnidirectional antenna is disposed, and is made of a dielectric material that is a part or whole of a rotationally symmetric body having a rotationally symmetric convex outer curved surface around a central axis of the through hole. lens.

2. 2. The lens of claim 1, an inner surface of the lens body facing the through hole is spaced apart from a central axis of the through hole by λ / 2π (λ: wavelength of radio waves) or more; The separation distance is equal to the radial focal length F of the lens body. lens.

3. 2. The lens of claim 1, The outer curved surface of the lens body has a relative dielectric constant ε ｒ , an aspheric surface determined based on a focal length F in a radial direction of the lens body and a distance R from a center to an edge of the inner surface of the lens body in a direction along the rotation axis, lens.

4. 2. The lens of claim 1, A lens, wherein a focal length F in a radial direction of the lens body is an integer multiple of λ / 2 (λ: wavelength of radio waves).

5. 2. The lens of claim 1, The lens body has a shape in which a part of the rotationally symmetric body in the circumferential direction is missing. lens.

6. A reflective member that reflects the radio waves is disposed in a missing portion in which a part of the lens body in the circumferential direction is missing. lens.

7. 2. The lens of claim 1, The rotationally symmetric body has a monorotationally symmetric shape around the central axis of the through hole or a plurality (n) rotationally symmetric shape around the central axis of the through hole. lens.

8. 8. An antenna device comprising: a lens according to claim 1; and an antenna having omnidirectional properties in a horizontal plane, disposed in a through hole of the lens.

9. The antenna device according to claim 8; a wireless communication unit connected to the antenna of the antenna device; A communication device comprising:

10. A mobile body comprising the communication device according to claim 9, for performing inter-mobile communication with another mobile body located at least one of the front and rear in a moving direction.

11. The moving body according to claim 10, the antenna device has a directional beam with a beam width of 150 degrees or more and 180 degrees or less in mobile-to-mobile communication with the other mobile body, Mobile body.

12. The moving body according to claim 10, a plurality of the antenna devices are provided at least one of a front and a rear in a moving direction of the moving body, Transmitting or receiving the same radio wave via the plurality of antenna devices; Mobile body.

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