Antenna device

Abstract

Provided is an antenna device whose characteristics are enhanced (radio waves can be efficiently emitted from an extended antenna), without placing a communication unit that performs wireless communication with the outside of a vehicle near a ring-shaped structure of the vehicle, thereby allowing flexibility in the installation height of the communication unit. The antenna device (1A) is installed on a vehicle (V), and includes a communication unit (10) that performs wireless communication with the outside of the vehicle (V), a metal support (20) that functions as an extended antenna, the communication unit (10) includes a housing (11) and a substrate (12), the substrate (12) is housed in the housing (11) and a pattern antenna (12a) is formed on the substrate (12), the metal support (20) includes a first portion (21) that is fixed to the housing (11) and a second portion (22) that is fixed to the vehicle (V), the first portion (21) and the pattern antenna (12a) face each other with a portion of the housing (11) interposed therebetween in such a manner that at least a portion of the pattern antenna (12a) and the metal support (20) are spatially coupled.

Description

Technical Field

[0001] This invention relates to antenna devices. Background Technology

[0002] For example, Patent Document 1 discloses an antenna device in which a feed element (also used as a feed element for an antenna element) mounted on the top of a vehicle and a ring structure of the vehicle to which the top of the vehicle is fixed are spatially coupled (non-contact electromagnetic coupling).

[0003] Citation List

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2003-249812 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, one problem with the antenna device disclosed in Patent Document 1 is that, in the case of using a communication unit that communicates wirelessly with the outside of the vehicle instead of the top of the vehicle on which the feeding element is installed, the communication unit needs to be placed near the ring structure of the vehicle to achieve spatial coupling between the communication unit and the ring structure of the vehicle, which limits the flexibility of the installation of the communication unit.

[0008] The object of the present invention is to provide an antenna device whose characteristics are enhanced (efficiently transmitting radio waves from an extended antenna) without requiring a communication unit that communicates wirelessly with the outside of the vehicle to be placed near the ring structure of the vehicle, thereby allowing for a high degree of flexibility in the installation of the communication unit.

[0009] Solution for solving the problem

[0010] The antenna device according to the invention is an antenna device mounted on a vehicle, the antenna device comprising: a communication unit configured to wirelessly communicate with the outside of the vehicle; and a metal bracket configured to also serve as an extended antenna, wherein the communication unit includes a housing and a substrate, the substrate being housed in the housing and having a patterned antenna formed thereon, the metal bracket including a first portion fixed to the housing and a second portion fixed to the vehicle, and the first portion and the patterned antenna being opposite each other such that a portion of the housing is located between the first portion and the patterned antenna, such that at least a portion of the metal bracket and the patterned antenna are spatially coupled.

[0011] The effects of the invention

[0012] According to the present invention, an antenna device is provided whose characteristics are enhanced (efficiently transmitting radio waves from an extended antenna) without requiring a communication unit that communicates wirelessly with the outside of the vehicle to be placed near the ring structure of the vehicle, thereby allowing for a high degree of flexibility in the installation of the communication unit. Attached Figure Description

[0013] Figure 1 This is a schematic block diagram of the antenna device 1A according to the first exemplary embodiment.

[0014] Figure 2 This is a schematic cross-sectional view of the antenna device 1B according to the second example embodiment.

[0015] Figure 3A This is an example of calculating the transmission mode of the radio field strength without using the metal bracket 20, which is also used as an extended antenna.

[0016] Figure 3B This is an example of calculating the transmission mode of the radio field strength when using the metal bracket 20, which is also used as an extended antenna.

[0017] Figure 4 This is a schematic cross-sectional view of the antenna device 1C according to the third exemplary embodiment. Detailed Implementation

[0018] (First Example Implementation)

[0019] Antenna device 1A according to a first exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same structural elements, and redundant descriptions thereof are omitted.

[0020] See below for reference Figure 1 The structure of the antenna device 1A according to the first example embodiment is described.

[0021] Figure 1 This is a schematic block diagram of the antenna device 1A according to the first exemplary embodiment.

[0022] like Figure 1 As shown, the antenna device 1A according to the first example embodiment is an antenna device mounted on a vehicle V. The antenna device 1A includes a communication unit 10 (vehicle-mounted communication unit) and a metal bracket 20, wherein the communication unit 10 wirelessly communicates with the outside of the vehicle V, and the metal bracket 20 also serves as an extension antenna.

[0023] The communication unit 10 includes a housing 11 and a substrate 12 housed in the housing 11, and a patterned antenna 12a is formed on the substrate 12. The metal bracket 20 includes a first portion 21 fixed to the housing 11 and a second portion 22 fixed to a vehicle V (e.g., the inner surface of the instrument panel 30 or the vehicle frame (not shown)).

[0024] The first part 21 and the patterned antenna 12a are positioned opposite each other with a portion of the housing 11 (e.g., the upper part 11a) between the first part 21 and the patterned antenna 12a, such that at least a portion of the patterned antenna 12a is spatially coupled (non-contact electromagnetic coupling) to the metal support 20.

[0025] As described above, according to the first example embodiment, an antenna device 1B is provided with enhanced characteristics (efficiently transmitting radio waves from an extended antenna) without requiring the communication unit 10, which communicates wirelessly with the outside of the vehicle V, to be placed near the ring structure of the vehicle, thereby allowing for a high degree of flexibility in the installation of the communication unit 10.

[0026] This is achieved as follows. Since the first portion 21 and the patterned antenna 12a are positioned opposite each other with a portion of the housing 11 (e.g., the upper portion 11a) between them, at least a portion of the patterned antenna 12a is spatially coupled (non-contact electromagnetic coupling) to the metal support 20. Therefore, the driving current of the patterned antenna 12a in the communication unit 10 induces a current in the metal support 20, which in turn causes the transmission of radio waves (radio waves for communication) from the metal support 20. In other words, this is because the metal support 20 functions as an extended antenna in addition to fixing the communication unit 10 to the vehicle V.

[0027] (Second Example Implementation)

[0028] Antenna device 1B according to a second exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same structural elements, and redundant descriptions thereof are omitted.

[0029] See below for reference Figure 2 The structure of the antenna device 1B according to the second example embodiment is described.

[0030] Figure 2 This is a schematic cross-sectional view of the antenna device 1B according to the second example embodiment. Figure 2 This is a schematic cross-sectional view showing the instrument panel 30 in the longitudinal direction of the vehicle when viewed from the side. The same elements as in the first example embodiment are indicated by the same reference numerals, and their descriptions are appropriately omitted. Note that the location, orientation, and angle at which the communication unit 10 is mounted are not limited to those shown in the figure.

[0031] like Figure 2 As shown, antenna device 1B is mounted on vehicle V. Antenna device 1B includes communication unit 10 (also referred to as vehicle-mounted communication unit), metal bracket 20, and instrument panel 30. Communication unit 10 communicates wirelessly with the outside of vehicle V. Metal bracket 20 fixes communication unit 10 to vehicle V and also serves as an extension antenna. Measuring instruments (not shown) of vehicle V are placed on instrument panel 30. Communication unit 10 and metal bracket 20 are each positioned opposite the inner surface of instrument panel 30 (the back of instrument panel 30 when viewed from inside vehicle).

[0032] For example, communication unit 10 is a data communication module that wirelessly communicates with the outside of a vehicle. Communication unit 10 includes a housing 11 and a substrate 12 (also referred to as a product substrate). Housing 11 is made of resin (synthetic resin). Substrate 12 and a backup battery (not shown) are housed in housing 11. A patterned antenna 12a is formed on substrate 12. For example, patterned antenna 12a is a monopole antenna, L-antenna, inverted L-antenna, F-antenna, or inverted F-antenna. With patterned antenna 12a located near the upper part 11a of housing 11, substrate 12 is placed inside housing 11. In addition to patterned antenna 12a, electronic components constituting communication unit 10 (i.e., those controlling wireless communication) are mounted on substrate 12; however, examples of electronic components are omitted in the figures.

[0033] The communication unit 10 is fixed to the vehicle V by a metal bracket 20.

[0034] The metal support 20 includes a first part 21 fixed to the housing 11 and a second part 22 fixed to the vehicle V.

[0035] For example, the first portion 21 is fixed to the upper part 11a (upper surface) of the housing 11. This fixing uses known fixing components (e.g., screws). The first portion 21 and the patterned antenna 12a are positioned opposite each other such that a portion of the housing 11 (e.g., the upper part 11a) is located between the first portion 21 and the patterned antenna 12a, such that at least a portion of the patterned antenna 12a is spatially coupled (non-contact electromagnetic coupling) to the metal support 20. Specifically, the first portion 21 is fixed at a location that does not contact the patterned antenna 12a and where an induced current appears in the patterned antenna 12a due to the driving current of the patterned antenna 12a.

[0036] Metal bracket 20 extends upward from first portion 21 (e.g., toward second portion 22). For example, second portion 22 is secured to a vehicle assembly (such as the inner surface of instrument panel 30 or vehicle frame (not shown)) located above housing 11.

[0037] The following describes an example of the operation of the antenna device 1B having the above structure.

[0038] In the antenna device 1B with the above-described structure, since the first part 21 and the patterned antenna 12a are positioned opposite each other with a portion of the housing 11 (e.g., the upper part 11a) between the first part 21 and the patterned antenna 12a, at least a portion of the patterned antenna 12a is spatially coupled (non-contact electromagnetic coupling) to the metal support 20. Therefore, the driving current of the patterned antenna 12a in the communication unit 10 induces a current in the metal support 20, which in turn causes the transmission of radio waves (radio waves for communication) from the metal support 20. In this way, the metal support 20, in addition to its function of fixing the communication unit 10 to the vehicle V, also functions as an extended antenna.

[0039] Figure 3 shows a comparative example of radio field strength. Figure 3A This is an example of calculating the transmission mode of the radio field strength without using the metal bracket 20, which also serves as an extended antenna. Figure 3B This is an example of calculating the transmission mode of the radio field strength when using the metal bracket 20, which is also used as an extended antenna.

[0040] refer to Figure 3A and Figure 3B The radio field strength (characteristics) is enhanced by using a metal bracket 20, which also serves as an extended antenna, as described in the second example embodiment.

[0041] As described above, according to the second example embodiment, an antenna device 1B is provided with enhanced characteristics (efficiently transmitting radio waves from an extended antenna) without requiring the communication unit 10, which communicates wirelessly with the outside of the vehicle V, to be placed near the ring structure of the vehicle, thereby allowing for a high degree of flexibility in the installation of the communication unit 10.

[0042] This is achieved as follows. Since the first portion 21 and the patterned antenna 12a are positioned opposite each other with a portion of the housing 11 (e.g., the upper portion 11a) between them, at least a portion of the patterned antenna 12a is spatially coupled (non-contact electromagnetic coupling) to the metal support 20. Therefore, the driving current of the patterned antenna 12a in the communication unit 10 induces a current in the metal support 20, which in turn causes the transmission of radio waves (radio waves for communication) from the metal support 20. In other words, this is because the metal support 20 functions as an extended antenna in addition to fixing the communication unit 10 to the vehicle V.

[0043] Furthermore, according to the second example embodiment, since the metal bracket 20 also serves as an extension antenna, the need for a non-contact antenna integrally molded with the housing 11 is eliminated. This achieves a reduction in the weight and cost of the housing 11.

[0044] Furthermore, according to the second example embodiment, since the metal bracket 20 (extended antenna) is allowed to be mounted away from the substrate 12 in the direction of the upper surface of the instrument panel 30, the receiving sensitivity can be improved.

[0045] (Third Example Implementation)

[0046] The antenna device 1C according to a third exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same structural elements, and redundant descriptions thereof are omitted. Note that the position, orientation, and angle at which the communication unit 10 is mounted are not limited to those shown in the drawings.

[0047] Figure 4 This is a schematic cross-sectional view of the antenna device 1C according to the third exemplary embodiment. Figure 4 This is a schematic cross-sectional view showing the instrument panel 30 in the longitudinal direction of the vehicle when viewed from the side.

[0048] The following mainly describes the differences from the second example embodiment.

[0049] like Figure 4As shown, a molded resin portion 31 is placed between the first portion 21 of the metal bracket 20 and the housing 11 of the communication unit 10. The molded resin portion 31 is placed in this manner so that the metal bracket 20 and the patterned antenna 12a are positioned and shaped such that spatial coupling (non-contact electromagnetic coupling) is achieved by bringing the housing 11 of the communication unit 10 and the metal bracket 20 into contact with the molded resin portion 31 (i.e., to achieve positioning between the metal bracket 20 and the patterned antenna 12a). Specifically, the first portion 21 is fixed to the side portion 11b (side surface) of the housing 11, for example, by the molded resin portion 31. The molded resin portion 31 is, for example, part of the instrument panel 30. The first portion 21 and the patterned antenna 12a are positioned opposite each other such that a portion of the housing 11 (e.g., the side portion 11b) and the molded resin portion 31 are positioned between the first portion 21 and the patterned antenna 12a, such that at least a portion of the patterned antenna 12a and the metal bracket 20 are spatially coupled by the molded resin portion 31. The shape, size, etc., of the molded resin portion 31 are designed to achieve proper spatial coupling between the metal support 20 and the patterned antenna 12a when the molded resin portion 31 is positioned between the metal support 20 and the patterned antenna 12a (and when the metal support 20 and the patterned antenna 12a are each in contact with the molded resin portion 31). Otherwise, this structure is identical to that of the antenna device 1C according to the second example embodiment.

[0050] As described above, the third example embodiment has the same effect as the second example embodiment.

[0051] Furthermore, by utilizing the molded resin section 31, appropriate spatial coupling is achieved between the metal bracket (extended antenna), which is optimally designed for each vehicle (with a shape for efficient radio wave transmission), and the communication unit 10 (patterned antenna 12a). Therefore, the installation process of the communication unit 10 and the metal bracket 20 is improved when assembling the vehicle.

[0052] All the values ​​shown in the above example embodiments are merely illustrative, and of course, different appropriate values ​​can be used.

[0053] The above exemplary embodiments are given by way of example only in all respects. The invention should not be construed as limiting by the description in the above exemplary embodiments. The invention can be implemented in various ways without departing from its spirit and essential features.

[0054] Although the present invention has been described above with reference to exemplary embodiments, the present invention is not limited to the above exemplary embodiments. Various changes and modifications to the structure and details of the present invention that are obvious to those skilled in the art can be made without departing from the scope of the present invention.

[0055] This application is based on and claims priority to Japanese Patent Application 2020-007197, filed on January 21, 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0056] List of reference numerals

[0057] Antenna devices 1A, 1B, and 1C

[0058] 10 communication units

[0059] 11. Shell

[0060] 11a Upper part

[0061] 11b side

[0062] 12 substrates

[0063] 12a Patterned Antenna

[0064] 20 metal brackets

[0065] 21 Part 1

[0066] 22 Part Two

[0067] 30 dashboard

[0068] 31 Molding Resin Section

[0069] V-Vehicle

Claims

1. An antenna device mounted on a vehicle, the antenna device comprising: A communication unit configured to wirelessly communicate with the outside of the vehicle; Metal bracket, which is configured to also serve as an extension antenna; as well as The dashboard, the molded resin section is a part of the dashboard. The communication unit includes a housing and a substrate, the substrate being housed within the housing and having a patterned antenna formed on it. The metal bracket includes a first portion fixed to the housing and a second portion fixed to the dashboard. The molded resin portion is placed between the first part and the housing, and The first portion and the patterned antenna are positioned opposite each other with a portion of the housing and the molded resin portion between the first portion and the patterned antenna, such that at least a portion of the patterned antenna and the metal support are spatially coupled through the molded resin portion.

2. The antenna device according to claim 1, wherein, The metal support extends upward from the first part.

3. The antenna device according to claim 1, wherein, The communication unit and the metal bracket are each positioned opposite the inner surface of the dashboard.

4. The antenna device according to any one of claims 1 to 3, wherein, The shell is made of resin.

5. The antenna device according to claim 1, wherein, The molded resin portion is disposed between the first portion and the housing, and the shape and size of the molded resin portion are designed such that the first portion and the patterned antenna are appropriately coupled in space while the first portion and the patterned antenna are positioned between the first portion and the patterned antenna, and such that the first portion and the housing are each in contact with the molded resin portion.

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