Antenna device and wireless communication system

Abstract

To provide an antenna device with which, of a simple structure though, it is possible to radiate a radio wave to an exact range.SOLUTION: An antenna device 100 is arranged in the inside of a vehicle 10 and used to relay wireless communication, the antenna device 100 comprising a substrate 101 and a first array antenna unit. A plurality of antenna elements 110 is arranged to the first array antenna unit at prescribed positions of the substrate running along a first direction in a first plane that is parallel to the travel direction and the vertical direction of the vehicle 10. The radio wave radiation angle in the first plane of the first array antenna unit is smaller than the radio wave radiation angle in a second plane that is perpendicular to the travel direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an antenna device and a wireless communication system. [Background technology]

[0002] Conventionally, in wireless communication between equipment inside a vehicle and a base station outside the vehicle, a technology has been proposed in which a device for relaying and transmitting wireless signals is provided inside the vehicle to facilitate information communication inside and outside the vehicle. Patent Document 1 discloses an in-vehicle communication repeater that relays wireless communication performed inside the vehicle. The in-vehicle communication repeater disclosed in Patent Document 1 adjusts the directivity of the antenna to enable communication compatible with various types of vehicles with different cabin structures. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-103821 Summary of the Invention [Problem to be solved by the invention]

[0004] The in-vehicle communication repeater disclosed in Patent Document 1 changes the position of the antenna by a motor provided in the in-vehicle communication repeater according to the internal structure of the vehicle. In other words, the in-vehicle communication repeater requires a motor and a mechanism for controlling the motor to adjust the directivity of the antenna according to the internal structure of the vehicle.

[0005] The present invention has been made in view of the problems inherent in the conventional technology, and an object of the present invention is to provide an antenna device that has a simple configuration and is capable of radiating radio waves to an appropriate range. [Means for solving the problem]

[0006] An antenna device according to an embodiment of the present invention is an antenna device that is arranged inside a vehicle and is used to relay wireless communications, and includes a substrate and a first array antenna unit in which a plurality of antenna elements are arranged at a predetermined position on the substrate, along a first direction in a first plane that is parallel to the direction of travel and the up-down direction of the vehicle, and the radiation angle of radio waves in the first plane of the first array antenna unit is smaller than the radiation angle of radio waves in a second plane that is perpendicular to the direction of travel.

[0007] Another aspect of the present invention provides a wireless communication system comprising an exterior antenna for transmitting and receiving wireless signals to and from a base station outside the vehicle, and an interior antenna connected to the exterior antenna for relaying signals transmitted and received between communication equipment inside the vehicle and the exterior antenna, wherein the interior antenna comprises a substrate and a first array antenna unit having a plurality of antenna elements arranged at a predetermined position on the substrate, along a first direction in a first plane that is parallel to the direction of travel and the up-down direction of the vehicle, and wherein the radiation angle of radio waves in the first plane of the first array antenna unit is smaller than the radiation angle of radio waves in a second plane that is perpendicular to the direction of travel. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an antenna device that can radiate radio waves to an appropriate range with a simple configuration. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing the configuration of an in-vehicle network to which an antenna device according to an embodiment of the present invention is applied; [Figure 2] 1 is a diagram illustrating a configuration of an antenna device according to a first embodiment. [Figure 3A] 2A and 2B are diagrams for explaining radio waves radiated from the antenna device according to the first embodiment. [Figure 3B] 2A and 2B are diagrams for explaining radio waves radiated from the antenna device according to the first embodiment. [Figure 4A]FIG. 10 is a diagram illustrating a configuration of an antenna device according to a second embodiment. [Figure 4B] 10A and 10B are diagrams illustrating radio waves radiated from an antenna device according to a second embodiment. [Figure 5] FIG. 10 is a diagram illustrating a configuration of an antenna device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The antenna device 100 according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for the sake of explanation and may differ from the actual ratios. In addition, in the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0011] FIG. 1 is a diagram showing the configuration of a network system 1 to which an antenna device 100 according to this embodiment is applied. As shown in FIG. 1, the network system 1 is configured to include an exterior antenna 20 and an antenna device 100, which is an interior antenna, in a vehicle 10. The antenna device 100 according to this embodiment and the exterior antenna 20 are connected by a cable 30. That is, in this embodiment, the antenna device 100 is disposed inside the vehicle 10 and is an antenna device for relaying wireless communications. The network system 1 corresponds to a wireless communication system.

[0012] The exterior antenna 20 is an antenna for transmitting and receiving wireless signals to and from a base station or the like outside the vehicle 10 between communication equipment inside the vehicle 10 and a base station or the like outside the vehicle 10. The antenna device 100 receives signals received by the exterior antenna 20 via a cable 30 and radiates the signals to the communication equipment inside the vehicle 10. The antenna device 100 also transmits signals received from the communication equipment inside the vehicle 10 to the exterior antenna 20 via the cable 30, and the signals are then transmitted from the exterior antenna 20 to an external base station or the like. In other words, the antenna device 100 relays signals transmitted and received between the communication equipment inside the vehicle 10 and the exterior antenna 20. In this embodiment, the cable 30 is configured with a coaxial cable or an optical fiber. The antenna device 100 corresponds to an in-vehicle antenna. In this embodiment, the base station includes not only fixed base stations but also mobile base stations.

[0013] In this specification, the wireless communication operation of the antenna device 100 will be described when the antenna device 100 receives a signal via the exterior antenna 20 via the cable 30 and radiates the signal to a communication device inside the vehicle 10. Note that the same effect can be obtained when the antenna device 100 receives a signal from a communication device.

[0014] 1 is defined as the X1 direction, and the direction opposite to the traveling direction of the vehicle 10 is defined as the X2 direction. The axis indicated by the X1 direction and the X2 direction is defined as the X axis (see FIG. 4A).

[0015] 1, the Y1 direction refers to the direction from the back to the front of the drawing, and the Y2 direction refers to the direction opposite to the Y1 direction. That is, the Y1 direction and the Y2 direction are directions perpendicular to the traveling direction of the vehicle 10 and correspond to the lateral direction (left-right direction) of the vehicle 10. The axis indicated by the Y1 direction and the Y2 direction is the Y axis (see FIG. 4A).

[0016] Furthermore, the Z1 direction refers to the direction toward the top of the drawing in the vertical direction of the vehicle 10 shown in Fig. 1, and the Z2 direction refers to the direction toward the bottom, opposite to the Z1 direction, in the vertical direction of Fig. 1. In other words, the Z1 direction and the Z2 direction are directions perpendicular to the traveling direction of the vehicle 10, and correspond to the up-down direction on the vehicle 10. The axis indicated by the Z1 direction and the Z2 direction is the Z axis (see Fig. 4A).

[0017] (First embodiment) Fig. 2 is a diagram showing the configuration of the antenna device 100 according to the first embodiment. Fig. 2 is a plan view seen from the lower side to the upper side (Z1 direction) in the vertical direction of the vehicle 10. The antenna device 100 according to the first embodiment has a bent shape as shown in Figs. 3A and 3B described below.

[0018] The antenna device 100 includes a substrate 101, a plurality of antenna elements 110, a terminal 120, and a feeder line .

[0019] In this embodiment, the substrate 101 is a flexible and bendable substrate, and is made of, for example, a liquid crystal polymer film.

[0020] In the first embodiment, the antenna elements 110 are configured as a linear array antenna arranged at equal intervals in the X1 direction (X2 direction) as shown in FIG. 2. In the first embodiment, the traveling direction of the vehicle 10 is the X1 direction. In the first embodiment, the areas where the antenna elements 110 are arranged in a row at equal intervals are referred to as array antenna section 111a and array antenna section 111b. The array antenna section 111a corresponds to the first array antenna section. The array antenna section 111b corresponds to the second array antenna section. Hereinafter, when it is not necessary to distinguish between the array antenna sections in the description, they will simply be referred to as "array antenna section 111."

[0021] The terminal 120 is a terminal that connects the cable 30 and the feeder line 130. In this embodiment, the terminal 120 is a feeder circuit that is used to excite the antenna element 110. Note that the terminal 120 may have the functions of a phase adjuster, a high-power amplifier, and / or a low-noise amplifier as a feeder circuit.

[0022] The feeder line 130 is a signal line for supplying signals from the terminal 120 to the plurality of antenna elements 110. In the first embodiment, the feeder line 130 is configured to branch a line in a tournament shape. However, the feeder line 130 is not limited to this configuration. For example, the feeder line 130 may be configured as a series feed circuit in which the line is branched in sequence from the terminal 120 using a directional coupler or an unequal divider to feed power to the antenna elements 110.

[0023] 3A is a schematic diagram of the antenna device 100 when viewed from the IIIA-IIIA direction in FIG. 2. As described above, in the first embodiment, the traveling direction of the vehicle 10 is the X1 direction. The up-down direction of the vehicle 10 is the Z1 direction and the Z2 direction. That is, the plane shown in FIG. 3A is a plane parallel to the traveling direction and up-down direction of the vehicle 10. In this specification, the plane parallel to the traveling direction and up-down direction of the vehicle 10 is referred to as the first plane.

[0024] As shown in Fig. 3A, the array antenna unit 111a has a plurality of antenna elements 110 arranged at positions along a first direction on a first plane. That is, the array antenna unit 111a has a plurality of antenna elements 110 arranged at predetermined positions on a substrate, at positions along the first direction on a first plane that is parallel to the traveling direction and the up-down direction of the vehicle 10. In the example shown in Fig. 3A, the radiation angle of radio waves on the first plane of the array antenna unit 111a is indicated by radiation angle A. In this embodiment, the radiation angle of radio waves is the half-power angle in the radiation pattern of the radio waves. The half-power angle indicates the angular range over which the power radiated from the antenna becomes half of its maximum value, and indicates the sharpness of the directivity.

[0025] 3A, array antenna unit 111b has a plurality of antenna elements 110 arranged at positions along the second direction on the first plane. That is, array antenna unit 111b has a plurality of antenna elements 110 arranged at predetermined positions on the substrate, at positions along the second direction on the first plane that is parallel to the traveling direction and the up-down direction of vehicle 10. In the example shown in FIG. 3A, the radiation angle of radio waves on the first plane of array antenna unit 111b is indicated by radiation angle A.

[0026] Fig. 3B is a schematic diagram of the antenna device 100 when viewed from the IIIB-IIIB direction in Fig. 2. The plane shown in Fig. 3B is perpendicular to the traveling direction of the vehicle 10. In this specification, the plane perpendicular to the traveling direction of the vehicle 10 is referred to as a second plane.

[0027] 3B, the radiation angle of the radio waves on the second plane of the array antenna unit 111b is indicated by radiation angle B. Note that the radiation angle of the radio waves on the second plane of the array antenna unit 111a (not shown) is also the same as the radiation angle of the radio waves on the second plane of the array antenna unit 111b.

[0028] 3A and 3B, radiation angle A is smaller than radiation angle B. This is due to the characteristics based on the arrangement of antenna elements 110 of array antenna unit 111a and array antenna unit 111b, and the radiation angle of radio waves is narrow in the direction in which antenna elements 110 are arranged, while the power per unit area is large. Also, in the direction perpendicular to the direction in which antenna elements 110 are arranged, the radiation angle of radio waves is large, while the power per unit area is small. That is, in the example shown in FIG. 3A, the radiation power per unit area is large, while in the example shown in FIG. 3B, the radiation power per unit area is small.

[0029] As shown in FIG. 3A, in the direction of travel (front-rear direction) of the vehicle 10, the radio waves from the antenna device 100 have a narrow radiation angle and high power per unit area. On the other hand, in the lateral direction of the vehicle 10 as shown in FIG. 3B, the radio waves from the antenna device 100 have a wide radiation angle and low power per unit area. That is, when seats are lined up inside the vehicle 10, narrowing the radiation angle in the front-rear direction of the vehicle 10 makes it possible to radiate strong radio waves to people in front of and behind the seat backs. On the other hand, in the lateral direction inside the vehicle 10 where the radio waves are not blocked by the seats, weaker radio waves than in the front-rear direction can be radiated over a wide range with a wide radiation angle. Specifically, by arranging the seats inside the vehicle 10 vertically between the array antenna unit 111a and the array antenna unit 111b, the radio waves are not blocked by the seats, and the radio waves can be radiated more efficiently to the required space. That is, it is possible to radiate radio waves to a required space by having array antenna unit 111a radiate radio waves to an area in front of the seats inside vehicle 10, and array antenna unit 111b radiate radio waves to an area behind the seats inside vehicle 10. Furthermore, antenna device 100 does not radiate radio waves to areas where radio wave radiation is not required, such as the ceiling inside the vehicle, thereby enabling efficient radiation.

[0030] Furthermore, in the antenna device 100 according to the first embodiment, the first straight line L1 indicated in the first direction and the second straight line L2 indicated in the second direction are positioned so as to intersect at a predetermined angle θ on the first plane. That is, by bending the substrate 101 between the array antenna unit 111a and the array antenna unit 111b at a predetermined angle, the antenna device 100 having the shape shown in Fig. 3A can be realized. This makes it possible to radiate radio waves over a wider area in the longitudinal direction of the vehicle than when the antenna device 100 is not bent.

[0031] 3A does not limit the configuration of the first embodiment. For example, the first straight line L1 indicated in the first direction and the second straight line L2 indicated in the second direction may be configured to be parallel to each other on the first plane. That is, by bending the substrate 101 180 degrees, the first straight line and the second straight line are positioned parallel to each other and coincide with the Z1 direction on the first plane. This enables the antenna device 100 to radiate radio waves over a wider area in the longitudinal direction of the vehicle.

[0032] As described above, antenna device 100 is disposed inside vehicle 10 and is used to relay wireless communications, and includes substrate 101 and array antenna unit 111a. Array antenna unit 111a has a plurality of antenna elements 110 disposed at predetermined positions on the substrate, along a first direction on a first plane that is parallel to the traveling direction and the up-down direction of vehicle 10. The radiation angle of radio waves on the first plane of array antenna unit 111a is smaller than the radiation angle of radio waves on a second plane that is perpendicular to the traveling direction.

[0033] As a result, when seats are lined up inside the vehicle 10, the antenna device 100 can radiate strong radio waves to people in front of and behind the seat backs by narrowing the radiation angle in the longitudinal direction of the vehicle 10. On the other hand, in the lateral direction inside the vehicle 10 where the radio waves are not blocked by the seats, the antenna device 100 can radiate weaker radio waves than in the longitudinal direction over a wide range at a radiation angle. That is, the antenna device 100 can efficiently cover the interior space of the vehicle by radiating radio waves. For example, this is more effective when the seats inside the vehicle 10 are divided into front and rear sections. Therefore, the antenna device 100 can radiate radio waves to an appropriate range with a simple configuration. Specifically, by arranging seats inside the vehicle 10 vertically between the array antenna unit 111a and the array antenna unit 111b, radio waves are not blocked by the seats, and radio waves can be radiated more efficiently to the required space. That is, it is possible to radiate radio waves to a required space by having array antenna unit 111a radiate radio waves to an area in front of the seats inside vehicle 10, and array antenna unit 111b radiate radio waves to an area behind the seats inside vehicle 10. Furthermore, antenna device 100 does not radiate radio waves to areas where radio wave radiation is not required, such as the ceiling inside the vehicle, thereby enabling efficient radiation.

[0034] The antenna device 100 according to the first embodiment may further include an array antenna unit 111b in which a plurality of antenna elements 110 are arranged at a predetermined position on the substrate, the position being along the second direction on the first plane. The radiation angle of radio waves from the array antenna unit 111b on the first plane is smaller than the radiation angle of radio waves on the second plane. This allows the array antenna unit 111a and the array antenna unit 111b to radiate radio waves over a wide area in the longitudinal direction of the vehicle 10.

[0035] Furthermore, in the antenna device 100 according to the first embodiment, the first straight line L1 indicated in the first direction and the second straight line L2 indicated in the second direction are positioned so as to intersect at a predetermined angle on the first plane, thereby enabling the antenna device 100 to radiate radio waves over a wider area in the longitudinal direction of the vehicle.

[0036] (Second embodiment) As described above, one specific embodiment has been described, but the above-described embodiment is merely an example and is not intended to limit the scope of the present invention. For example, the above-described embodiment illustrates a configuration in which an array antenna unit is provided on a first plane parallel to the traveling direction and the up-down direction of the vehicle 10. Here, a description will be given of a configuration of the antenna device 100 according to a second embodiment in which an array antenna unit is provided on the substrate 101 at a position other than the first plane, which differs from the first embodiment.

[0037] 4A, the substrate 101 of the antenna device 100 according to the second embodiment has a cylindrical shape with its central axis positioned in the vertical direction (Z-axis direction) of the vehicle. The substrate 101 according to the second embodiment also has a plurality of array antenna units 111 on its side surface. Furthermore, in the second embodiment, the substrate 101 has a first array antenna unit and a second array antenna unit on its side surface at a position where a first plane passing through the central axis intersects with the substrate 101.

[0038] In the antenna device 100 according to the second embodiment, a first line indicated in the first direction and a second line indicated in the second direction are parallel to each other on a first plane. As in the first embodiment, the array antenna section 111 positioned along the first direction on the first plane is referred to as the array antenna section 111a (first array antenna section). Similarly, the array antenna section 111 positioned along the second direction on the first plane is referred to as the array antenna section 111b (second array antenna section). In addition, the second embodiment includes at least one array antenna section 111 other than the array antenna section 111a and the array antenna section 111b. The array antenna section 111 other than the array antenna section 111a (first array antenna section) and the array antenna section 111b (second array antenna section) corresponds to a third array antenna section.

[0039] 4B is a diagram for explaining the radiation angle when the antenna device 100 according to the second embodiment includes six array antenna units 111. As described above, the array antenna unit 111 has a large radiation angle in a plane perpendicular to the direction in which the antenna elements 110 are arranged. Therefore, the antenna device 100 according to the second embodiment can radiate radio waves over a wide range of 360 degrees, as shown in FIG.

[0040] Furthermore, with respect to the first plane, similar to the first embodiment described above, radiation at a small radiation angle and with high power is possible. As a result, for example, by narrowing the radiation angle in the longitudinal direction of the vehicle 10, it is possible to radiate strong radio waves to people in front of and behind the seat back. On the other hand, it is possible to radiate weaker radio waves than in the longitudinal direction to a range with a large radiation angle over a wide range, including the lateral direction, inside the vehicle 10 that is not blocked by the seats.

[0041] Moreover, the antenna device 100 according to the second embodiment further includes an array antenna unit 111 (third array antenna unit) in which a plurality of antenna elements 110 are arranged at a position on the substrate 101 different from the first plane that is parallel to the traveling direction and the up-down direction of the vehicle 10. This enables the antenna device 100 to radiate radio waves over a wider range in the horizontal direction than when the antenna device 100 has two array antenna units 111.

[0042] In the antenna device 100 according to the second embodiment, the substrate 101 has a cylindrical shape with its central axis positioned in the vertical direction (Z-axis direction) of the vehicle, as shown in FIG. 4A . Furthermore, in the second embodiment, the substrate 101 includes a first array antenna unit and a second array antenna unit on a side surface of the substrate 101, at a position where a first plane passing through the central axis intersects with the substrate 101. As a result, the antenna device 100 according to the second embodiment has a certain distance between the first array antenna unit and the second array antenna unit. For example, when the angle θ shown in FIG. 3A in the first embodiment is set to 0 degrees, the first direction and the second direction are parallel to each other, and the first array antenna unit and the second array antenna unit are close to each other. In this case, noise such as crosstalk may occur between the antenna elements 110 and / or the feeder line 130 of the antenna device 100. On the other hand, the antenna device 100 according to the second embodiment has a certain gap between the first array antenna unit and the second array antenna unit, which makes it possible to suppress the occurrence of noise such as crosstalk caused by the antenna elements 110 and / or the feeder lines 130.

[0043] (Third embodiment) Next, a third embodiment will be described. In the following description, when the same reference numerals as those in the first and / or second embodiment are used, they indicate the same configuration as those in the first and / or second embodiment, and the preceding description will be referred to unless otherwise specified. Here, a description will be given of the configuration of the antenna device 100 according to the third embodiment, which is capable of more efficiently radiating radio waves to communication equipment inside the vehicle 10, that differs from that of the first and / or second embodiment.

[0044] 5 is a schematic diagram of an antenna device 100 according to a third embodiment. Compared to the antenna device 100 according to the second embodiment, the substrate 101 of the antenna device 100 according to the third embodiment has a truncated cone shape in which the diameter of the lower circle in the up-down direction is shorter than the diameter of the upper circle.

[0045] That is, the substrate 101 according to the third embodiment has a truncated cone shape whose central axis is located in the vertical direction (Z-axis direction) of the vehicle 10 and whose lower circle has a shorter diameter than the upper circle in the vertical direction of the vehicle 10. The substrate 101 according to the third embodiment also has a plurality of array antenna units 111 on its side surface.

[0046] As described above, the antenna device 100 according to the third embodiment has a truncated cone shape having the above-described characteristics, and therefore, the radio waves emitted from the array antenna unit 111 arranged on the side surface can reach the communication equipment inside the vehicle in a more accurate range.

[0047] Moreover, the antenna device 100 according to the third embodiment further includes an array antenna unit 111 (third array antenna unit) in which a plurality of antenna elements 110 are arranged at a position on the substrate 101 different from the first plane parallel to the traveling direction and the up-down direction of the vehicle 10. This makes it possible to radiate radio waves over a wider range in the horizontal direction than when there are two array antenna units 111.

[0048] (Other embodiments) Although the embodiments have been described in detail with reference to the drawings, the present embodiments are not limited to the contents described in the above embodiments. Furthermore, the components described above include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described above can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configurations can be made without departing from the spirit of the embodiments.

[0049] The features of the antenna device 100 and the wireless communication system will be described below.

[0050] The antenna device 100 according to the first aspect is disposed inside the vehicle 10 and is used to relay wireless communications. The antenna device 100 includes a substrate 101 and a first array antenna unit in which a plurality of antenna elements 110 are disposed at predetermined positions on the substrate and along a first direction on a first plane that is parallel to the traveling direction and the up-down direction of the vehicle 10. The radiation angle of radio waves on the first plane of the first array antenna unit is smaller than the radiation angle of radio waves on a second plane that is perpendicular to the traveling direction.

[0051] According to the above configuration, the antenna device 100 can efficiently cover the interior space of the vehicle by radiating radio waves. For example, this is more effective when the interior of the vehicle 10 has seats separated into front and rear sections. Therefore, the antenna device 100 can radiate radio waves to an appropriate range with a simple configuration.

[0052] The antenna device 100 according to the second aspect may further include a second array antenna unit in which a plurality of antenna elements 110 are arranged at a predetermined position on the substrate, along a second direction on the first plane. The radiation angle of radio waves on the first plane of the second array antenna unit may be smaller than the radiation angle of radio waves on the second plane.

[0053] According to the above configuration, the antenna device 100 can radiate radio waves over a wide area in the longitudinal direction of the vehicle 10 by the array antenna portion 111a and the array antenna portion 111b.

[0054] In the antenna device 100 according to the third aspect, a first line indicated in a first direction and a second line indicated in a second direction may be in a positional relationship in which they intersect at a predetermined angle on a first plane.

[0055] According to the above configuration, the antenna device 100 can radiate radio waves over a wider area in the front-to-rear direction of the vehicle.

[0056] The substrate 101 of the antenna device 100 according to the fourth aspect may have a truncated cone shape whose central axis is located in the vertical direction of the vehicle 10 and whose lower circle has a shorter diameter than the upper circle in the vertical direction of the vehicle 10. The substrate 101 may also include a first array antenna unit and a second array antenna unit on a side of the substrate 101 at a position where a first plane passing through the central axis intersects with the substrate 101.

[0057] According to the above configuration, the antenna device 100 has a truncated cone shape having the above-mentioned characteristics, and therefore, the radio waves emitted from the array antenna unit 111 arranged on the side can more accurately reach the communication equipment inside the vehicle.

[0058] The first straight line indicated in the first direction and the second straight line indicated in the second direction of the antenna device 100 according to the fifth aspect may be in a parallel positional relationship on the first plane.

[0059] According to the above configuration, the antenna device 100 can radiate radio waves over a wider area in the front-rear direction of the vehicle 10.

[0060] The substrate 101 of the antenna device 100 according to the sixth aspect may have a cylindrical shape with its central axis positioned in the up-down direction of the vehicle 10. The substrate 101 may also include a first array antenna unit and a second array antenna unit on a side surface of the substrate 101 at a position where a first plane passing through the central axis intersects with the substrate 101.

[0061] According to the above configuration, the antenna device 100 has a certain gap between the first array antenna unit and the second array antenna unit, which makes it possible to suppress the generation of noise such as crosstalk caused by the antenna elements 110 and / or the feeder lines 130.

[0062] The substrate 101 of the antenna device 100 according to the seventh embodiment may further include a third array antenna section in which a plurality of antenna elements 110 are arranged at a predetermined position on the substrate 101, which is different from the first plane.

[0063] According to the above configuration, the antenna device 100 can radiate radio waves over a wider range in the horizontal direction than when there are two array antenna units 111.

[0064] A wireless communication system according to an eighth aspect includes an exterior antenna 20 for transmitting and receiving wireless signals to and from a base station outside the vehicle, and an interior antenna connected to the exterior antenna 20 for relaying signals transmitted and received between communication equipment inside the vehicle and the exterior antenna 20. The interior antenna includes a substrate 101 and a first array antenna unit having a plurality of antenna elements 110 arranged at a predetermined position on the substrate and along a first direction on a first plane that is parallel to the traveling direction and the up-down direction of the vehicle 10. The radiation angle of radio waves on the first plane of the first array antenna unit is smaller than the radiation angle of radio waves on a second plane that is perpendicular to the traveling direction.

[0065] According to the above configuration, the wireless communication system can efficiently cover the interior space of the vehicle by radiating radio waves. For example, this is more effective when the interior of the vehicle 10 is divided into front and rear seats. Therefore, the wireless communication system can radiate radio waves relayed in communication between the exterior antenna 20 and communication devices inside the vehicle 10 to an appropriate range with a simple configuration. [Explanation of symbols]

[0066] 10 vehicles 20 External antenna 30 Cable 100 Antenna device 101 Substrate 110 antenna element 111, 111a, 111b Array antenna section 120 terminals 130 Power line

Claims

1. An antenna device that is disposed vertically above a seat inside a vehicle and that relays wireless communications, A substrate; a first array antenna unit in which a plurality of antenna elements are arranged at a predetermined position on the substrate, the first array antenna unit being located along a first direction on a first plane that is parallel to the traveling direction and the up-down direction of the vehicle; An antenna device, wherein a radiation angle of radio waves on the first plane of the first array antenna unit is smaller than the radiation angle of the radio waves on a second plane perpendicular to the propagation direction.

2. a second array antenna unit in which a plurality of the antenna elements are arranged at a predetermined position on the substrate along a second direction in the first plane, the radiation angle of the radio waves on the first plane of the second array antenna unit is smaller than the radiation angle of the radio waves on the second plane; The antenna device according to claim 1 .

3. a first straight line indicated in the first direction and a second straight line indicated in the second direction are in a positional relationship in which they intersect at a predetermined angle on the first plane; The antenna device according to claim 2 .

4. the substrate has a truncated cone shape with a central axis positioned in the vertical direction of the vehicle and a diameter of a circle positioned on a lower side in the vertical direction of the vehicle being shorter than a diameter of a circle positioned on an upper side, the substrate includes the first array antenna unit and the second array antenna unit on a side surface of the substrate at a position where the first plane passing through the central axis intersects with the substrate, The antenna device according to claim 3 .

5. a first straight line indicated in the first direction and a second straight line indicated in the second direction are in a parallel positional relationship on the first plane; The antenna device according to claim 2 .

6. the substrate has a cylindrical shape with a central axis positioned in the up-down direction of the vehicle, the substrate includes the first array antenna unit and the second array antenna unit on a side surface of the substrate at a position where the first plane passing through the central axis intersects with the substrate, 6. The antenna device according to claim 5.

7. the substrate further includes a third array antenna unit in which a plurality of the antenna elements are arranged at a predetermined position on the substrate, the third array antenna unit being different from the first plane; 7. The antenna device according to claim 4 or 6.

8. an external antenna for transmitting and receiving wireless signals to and from a base station outside the vehicle; an interior antenna connected to the exterior antenna and arranged vertically above a seat inside the vehicle to relay signals transmitted and received between a communication device inside the vehicle and the exterior antenna; The interior antenna is A substrate; a first array antenna unit in which a plurality of antenna elements are arranged at a predetermined position on the substrate, the first array antenna unit being located along a first direction on a first plane that is parallel to the traveling direction and the up-down direction of the vehicle; a radiation angle of the radio waves on the first plane of the first array antenna unit is smaller than a radiation angle of the radio waves on a second plane perpendicular to the traveling direction; Wireless communication system.

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