Antenna device, antenna, and vehicle

Abstract

An antenna device having a plurality of antennas arranged on a vehicle along a width direction intersecting with a traveling direction of the vehicle, the antenna device including: a first antenna that receives radio waves of a first frequency; and a second antenna that is positioned on the outside of the first antenna in the width direction of the vehicle and that is for radio waves of a second frequency band having a fractional bandwidth narrower than the first frequency.

Description

TECHNICAL FIELD

[0001] The present application relates to an antenna device, an antenna, and a vehicle. BACKGROUND

[0002] Patent Literature 1 discloses an antenna device including a plurality of antennas housed in an internal space of an antenna housing. PRIOR ART DOCUMENT PATENT LITERATURE

[0003] Patent Literature 1: Japanese Patent Application Publication No. 2016-208291 SUMMARY

[0004] In the case where a plurality of antennas are housed in a limited space like an antenna housing, as in the antenna device of Patent Literature 1, depending on the arrangement of the plurality of antennas, there are cases where the characteristics of the respective antennas are affected.

[0005] In view of the above-described problems, an object of the present application in one example is to achieve an antenna device in which a plurality of antennas can be appropriately arranged, an antenna constituting one of the antennas in the antenna device, and a vehicle mounting the antenna device or the antenna. Other objects of the present application will become clear in the description of the present specification.

[0006] One mode of the present application is an antenna device having a plurality of antennas arranged in a width direction intersecting a traveling direction of a vehicle, wherein the antenna device includes: a first antenna that handles a radio wave of a first frequency; and a second antenna that is located outside the width direction of the vehicle with respect to the first antenna and handles a radio wave of a second frequency band narrower than the first frequency in a fractional bandwidth.

[0007] One mode of the present application is an antenna constituting one of a plurality of antennas arranged in a width direction intersecting a traveling direction of a vehicle, wherein the antenna is located outside the width direction of the vehicle with respect to a first antenna that handles a radio wave of a first frequency and handles a radio wave of a second frequency band narrower than the first frequency in a fractional bandwidth.

[0008] One mode of the present application is a vehicle mounting a plurality of antennas arranged in a width direction intersecting a traveling direction of the vehicle, wherein the vehicle mounts a first antenna that handles a radio wave of a first frequency and a second antenna that handles a radio wave of a second frequency band narrower than the first frequency in a fractional bandwidth, from a center in the width direction of the vehicle toward an outside in the order of the first antenna and the second antenna.

[0009] The above-described antenna device according to the present application can realize an antenna device in which a plurality of antennas are appropriately arranged, an antenna constituting one of the antenna devices, and a vehicle mounting the antenna device or the antenna. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a side view of a vehicle C provided with the antenna device 10 of the embodiment, and shows a partial cross section. Figure 2 is a perspective view of an upper surface U of the vehicle C. Figure 3 is a perspective view of the antenna device 10. Figure 4 is a perspective view of the upper surface U of the vehicle C, and shows a state in which the housings 7, 8 are removed. Figure 5 is a perspective view of the antenna device 1A, and shows a state in which the housing 7 is removed. Figure 6 is a side view of the antenna 4. Figure 7A is a plan view of the antenna devices 1A, 1B. Figure 7B is a front view of the antenna devices 1A, 1B. Further, the illustration of the antenna 6 is omitted. Figure 8 is a side view of the antenna 5. Figure 9A is a graph showing the relationship between the element interval and the resonance frequency in the antenna 3. Figure 9B is a graph showing the relationship between the element interval and the resonance frequency in the antenna 2. Figure 10A is a graph showing the relationship between the element interval and the reflection loss in the antenna 3. Figure 10B is a graph showing the relationship between the element interval and the reflection loss in the antenna 2. Figure 11 is a table showing the sensitivity of the antenna 4 in the case where the antennas 2, 3 are adjacent and in the case where the antenna 4 is alone. Figure 12A is a calculation result showing how the gain (dBi) in the horizontal plane of the antenna 5 changes in the full azimuth in the case where the antenna 5 is arranged at the center in the width direction. Figure 12B is a calculation result showing how the gain (dBi) in the horizontal plane of the antenna 5 changes in the full azimuth in the case where the antenna 5 is arranged other than at the center in the width direction. Figure 13A is a graph showing a first example regarding the arrangement of the antenna 5. Figure 13Bis a view showing a second example of the configuration of the antenna 5. Figure 13C is a view showing a third example of the configuration of the antenna 5. Figure 14A is a view showing a first example of the relationship between the roof panel C1 and the antenna. Figure 14B is a view showing a second example of the relationship between the roof panel C1 and the antenna. Figure 15A is a view showing a first example of the configuration of a diversity antenna (Diversity Antenna) disposed in the recess R. Figure 15B is a view showing a second example of the configuration of the diversity antenna disposed in the recess R. DETAILED DESCRIPTION

[0011] According to the description and the drawings of the present specification, at least the following matters become clear.

[0012] Hereinafter, the preferred embodiments of the present application will be described with reference to the accompanying drawings. The same or equivalent constituent elements, parts, and the like shown in each drawing are denoted by the same reference numerals, and repetitive description is appropriately omitted.

[0013] In the following description, "substantially quadrangular" or "rectangular" refers to a shape composed of four sides, such as a square or a rectangle, for example, and can be at least a part of an angle cut diagonally with respect to a side, or at least one corner can include a curved line. Furthermore, in the shape of "substantially quadrangular" or "rectangular", a notch (recess) or a protrusion (projection) can be provided in a part of a side. == First Embodiment == <<Outline of Antenna Device 10>> Referring to Figure 1 and Figure 2 , the outline of the antenna device 10 of the present embodiment will be described.

[0014] Antenna device 10 includes antenna devices 1A and 1B (described later), each containing multiple antennas, and is a vehicle antenna device used in a vehicle C, which is a wheeled vehicle. Here, antenna device 10 is not limited to being installed in vehicle C, but also includes being incorporated into and used within vehicle C. In this embodiment, antenna device 10 is, for example, installed in a recess R located below the upper surface U (including the roof, roof panel, and tailgate) of vehicle C and above the interior roof surface. However, antenna device 10 may also be located in a position other than the recess R, such as a spoiler or a top-mounted console. Furthermore, antenna device 10 may also be an antenna device other than that used in vehicles. Antenna device 10 may also be used, for example, in flying objects such as drones, detectors, non-wheeled construction machinery, agricultural machinery, ships, and other mobile bodies. Furthermore, antenna device 100 may also be an antenna device used in non-mobile bodies.

[0015] The upper part of the recess R is made of a resin roof panel C1 (described later) that forms part of the upper surface U. Figure 8 A) Coverage.

[0016] The size of the recess R that accommodates the antenna device 10 is limited. Therefore, it is necessary to miniaturize the device constituting the antenna group including antennas 2, 3, 4, or antennas 5 and 6 while maintaining the sensitivity of each of the antennas 2, 3, and 4, or antennas 5 and 6, which are described later in the antenna device 10.

[0017] In the following description, such as Figure 1 As shown, the direction is defined based on the direction observed from the driver's seat S of vehicle C. Specifically, the forward direction observed from the driver's seat S of vehicle C is defined as forward, and its opposite direction (the rearward direction observed from the driver's seat S) is defined as rear. Furthermore, the direction perpendicular to the forward / backward direction and observed to the left from the driver's seat S of vehicle C is defined as left, and its opposite direction (the rightward direction observed from the driver's seat S) is defined as right. The left / right direction is also the width direction of vehicle C. Additionally, the direction perpendicular to both the forward / backward and left / right directions and observed upward from the driver's seat S of vehicle C is defined as upward, and its opposite direction (the downward direction observed from the driver's seat S) is defined as downward. The definitions of the above directions, etc., are common in other embodiments of this specification, unless specifically described otherwise.

[0018] Antenna device 10 includes antenna device 1A and antenna device 1B (e.g., see reference 1B). Figure 2 ).

[0019] like Figures 2 to 8As shown, the antenna device 1A is provided with the antennas 2, 3, 4, and a substantially rectangular parallelepiped-shaped case 7 that covers the antennas 2, 3, and 4 from above. Further, the antenna device 1A is provided with a ground portion 9 that functions as a ground for the antennas 2, 3, and 4, below the antennas 2, 3, and 4. The antenna device 1A is disposed to the right of the diversity antenna E and the diversity antenna D in the recess R. Further, the diversity antennas E and D can be other antennas, and can be electronic devices such as communication modules, reception units, camera units, and the like.

[0020] As shown, the antenna device 1A is provided with the antennas 2, 3, 4, and a substantially rectangular parallelepiped-shaped case 7 that covers the antennas 2, 3, and 4 from above. Further, the antenna device 1A is provided with a ground portion 9 that functions as a ground for the antennas 2, 3, and 4, below the antennas 2, 3, and 4. The antenna device 1A is disposed to the right of the diversity antenna E and the diversity antenna D in the recess R. Further, the diversity antennas E and D can be other antennas, and can be electronic devices such as communication modules, reception units, camera units, and the like. Figures 2 to 8 As shown, the antenna device 1A is provided with the antennas 2, 3, 4, and a substantially rectangular parallelepiped-shaped case 7 that covers the antennas 2, 3, and 4 from above. Further, the antenna device 1A is provided with a ground portion 9 that functions as a ground for the antennas 2, 3, and 4, below the antennas 2, 3, and 4. The antenna device 1A is disposed to the right of the diversity antenna E and the diversity antenna D in the recess R. Further, the diversity antennas E and D can be other antennas, and can be electronic devices such as communication modules, reception units, camera units, and the like.

[0021] (Antenna 2) As shown, the antenna device 1A is provided with the antennas 2, 3, 4, and a substantially rectangular parallelepiped-shaped case 7 that covers the antennas 2, 3, and 4 from above. Further, the antenna device 1A is provided with a ground portion 9 that functions as a ground for the antennas 2, 3, and 4, below the antennas 2, 3, and 4. The antenna device 1A is disposed to the right of the diversity antenna E and the diversity antenna D in the recess R. Further, the diversity antennas E and D can be other antennas, and can be electronic devices such as communication modules, reception units, camera units, and the like. Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7A and Figure 7B As shown, the antenna 2 is disposed to the leftmost side among the antennas 2, 3, and 4, and is disposed closest to the center line CL. The antenna 2 is an antenna capable of receiving digital radio broadcasting (Digital Audio Broadcasting, hereinafter referred to as "DAB"), and covers a frequency band of 174 MHz or more and 240 MHz or less (hereinafter, sometimes referred to as "DAB frequency band"). Further, the antenna 2 can be an antenna that covers radio waves of a frequency band for GSM, UMTS, LTE, telematics, Wi-Fi, Bluetooth, and the like. In addition, the antenna 2 can cover radio waves of a frequency band for a part of these frequency bands (for example, only for 5G). Further, Wi-Fi and Bluetooth are registered trademarks.

[0022] Details of the antenna 2 will be described later.

[0023] (Antenna 3) As shown, the antenna device 1A is provided with the antennas 2, 3, 4, and a substantially rectangular parallelepiped-shaped case 7 that covers the antennas 2, 3, and 4 from above. Further, the antenna device 1A is provided with a ground portion 9 that functions as a ground for the antennas 2, 3, and 4, below the antennas 2, 3, and 4. The antenna device 1A is disposed to the right of the diversity antenna E and the diversity antenna D in the recess R. Further, the diversity antennas E and D can be other antennas, and can be electronic devices such as communication modules, reception units, camera units, and the like. Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7A and Figure 7BAs shown, antenna 3 is an FM antenna positioned to the right of antenna 2 at a distance. Antenna 3 is designed to handle frequency bands with a fractional bandwidth narrower than antenna 2. In this embodiment, it is designed to handle frequency bands that can receive FM (Frequency Modulation) broadcasts, i.e., frequency bands between 88MHz and 108MHz (hereinafter sometimes referred to as "FM band").

[0024] Furthermore, antenna 3 can also be used to handle radio waves in frequency bands such as GSM, UMTS, LTE, telematics, Wi-Fi, and Bluetooth. Additionally, antenna 3 can also handle radio waves in a subset of these frequency bands (e.g., only for 5G). Regardless of the frequency band being handled, the fractional bandwidth of antenna 3 is configured to be narrower than that of antenna 2.

[0025] Details about antenna 3 will be described later.

[0026] (Antenna 4) like Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7A and Figure 7B As shown, antenna 4 is positioned to the right of antenna 3 at intervals. Antenna 4 is an antenna for receiving intermediate frequency broadcasts, and in this embodiment, it is designed to receive AM (Amplitude Modulation) broadcasts in the frequency band from 530 kHz to 1710 kHz (hereinafter sometimes referred to as the "AM band").

[0027] Antenna 4 is an AM antenna based on an inverted L-shape, comprising a substrate 41, a support 42, a coil 43, and an element 45 supported by the support 42 and positioned substantially parallel to the grounding portion 9 (see reference). Figure 5 , Figure 6 ).

[0028] The substrate 41 is a generally rectangular substrate disposed on the upper surface of the grounding portion 9 and electrically connected to the grounding portion 9. Electronic components (not shown) such as amplifiers that amplify signals from the antenna 4 are mounted on the substrate 41.

[0029] Furthermore, the term "connection" is not limited to physical connections but includes "electrical connections." Additionally, electrical connections are not limited to connections using conductors, but include connections using circuits, electronic components, etc. The same applies in the following description.

[0030] The support portion 42 is a component that supports the element 45 and is positioned approximately parallel to the grounding portion 9, extending upwards onto the substrate 41. A coil 43, electrically connected to the substrate 41, is wound around the outer periphery of the support portion 42. The coil 43, together with the element 45, is a component that responds to radio waves in the AM broadcast frequency band and is connected to both the element 45 and the substrate 41. Alternatively, the support portion 42 may be constructed of a wire or a conductor plate, omitting the coil 43 and connecting to both the element 45 and the substrate 41.

[0031] Element 45 is a plate-shaped capacitor loading element made of a conductor such as metal, and is roughly rectangular when viewed from above. Element 45 is located on the upper part of the support portion 42 and is electrically connected to the coil 43. The front-to-back length of element 45 is approximately 70 mm, and the left-to-right width is approximately 40 mm. Furthermore, element 45 can be any shape that effectively utilizes the area, such as a curved shape or a vortex shape, to suppress interference with other antennas.

[0032] In addition, it was used Figure 6 The description of the inverted L-shaped antenna structure of antenna 4 also applies to antenna 2. That is, antenna 2 is a DAB antenna based on the inverted L-shape, having a substrate 21, a support portion 22, a coil 23, and an element 25 supported by the support portion 22 and positioned approximately parallel to the ground portion 9 (see reference). Figure 5 ).

[0033] Like the substrate 41 of the antenna 4, the substrate 21 is a generally rectangular substrate disposed on the upper surface of the grounding portion 9 and electrically connected to the grounding portion 9. Electronic components such as amplifiers (not shown) that amplify signals from the antenna 2 are mounted on the substrate 21.

[0034] The support portion 22, like the support portion 42 of the antenna 4, is a component that supports the element 25 in a manner substantially parallel to the grounding portion 9, and is provided on the substrate 21 in a manner that extends upward toward the substrate 21. Although in Figure 5 Not shown in the figure, a coil 23 electrically connected to the substrate 21 is wound around the outer periphery of the support portion 22. The coil 23 is a component that, together with the component 25, responds to radio waves in the DAB band and is connected to the component 25 and the substrate 21. Alternatively, the support portion 22 may be constructed of wires or a conductor plate, omitting the coil 23 and connecting to the component 25 and the substrate 21.

[0035] Element 25, like element 45 of antenna 4, is a flat, capacitively loaded element made of a conductor such as metal, and is roughly rectangular when viewed from above. Element 25 is located on the upper part of support 22 and is electrically connected to coil 23. The front-to-back length of element 25 is approximately 70 mm, and the left-to-right width is approximately 130 mm. Furthermore, element 25 can be any shape that effectively utilizes the area, such as a curved shape or a vortex shape, to suppress interference with other antennas.

[0036] In addition, it used Figure 6 The description of the inverted L-shaped antenna structure of antenna 4 also applies to antenna 3. That is, antenna 3 is an FM antenna based on the inverted L-shape, having a substrate 31, a support portion 32, a coil 33, and an element 35 supported by the support portion 32 and positioned approximately parallel to the ground portion 9 (see reference). Figure 5 ).

[0037] Like the substrate 41 of the antenna 4, the substrate 31 is a generally rectangular substrate disposed on the upper surface of the grounding portion 9 and electrically connected to the grounding portion 9. Electronic components such as amplifiers (not shown) that amplify signals from the antenna 3 are mounted on the substrate 31.

[0038] The support portion 32, like the support portion 42 of the antenna 4, is a component that supports the element 35 in a manner substantially parallel to the grounding portion 9, and is provided on the substrate 31 in a manner that extends upward toward the substrate 31. Although in Figure 5 Not shown in the figure, a coil 33 electrically connected to the substrate 31 is wound around the outer periphery of the support portion 32. The coil 33 is a component that, together with the element 35, responds to radio waves in the FM frequency band and is connected to the element 35 and the substrate 31. Alternatively, the support portion 32 may be constructed of wires or a conductor plate, omitting the coil 33 and connecting to the element 35 and the substrate 31.

[0039] Element 35, like element 45 of antenna 4, is a flat, capacitively charged element made of a conductor such as metal, and is roughly rectangular when viewed from above. Element 35 is located on the upper part of support 32 and is electrically connected to coil 33. The front-to-back length of element 35 is approximately 70 mm, and the left-to-right width is approximately 100 mm. Furthermore, element 35 can be any shape that effectively utilizes the area, such as a curved shape or a vortex shape, to suppress interference with other antennas.

[0040] Furthermore, at least two of the substrate 21 of antenna 2, substrate 31 of antenna 3, and substrate 41 of antenna 4 can also be integrated as the same component.

[0041] Next, antennas 5 and 6, which are included in antenna device 1B located on the left side of antenna device 1A, will be described.

[0042] (Antenna 5) Antenna 5, for example, is designed to transmit and receive radio waves in the frequency band used by V2X (Vehicle to Everything).

[0043] like Figure 2 , Figure 4 , Figure 7A and Figure 7BAs shown, antenna 5 is an antenna contained within antenna device 1B and located to the left of antenna device 1A, positioned approximately at the center of the width relative to vehicle C. Antenna 5 includes a grounding portion 51, an element 52, a reflector 53, and a flat, generally rectangular substrate 54 (see reference). Figure 8 ).

[0044] The grounding portion 51 is a generally cuboid-shaped component made of a conductor such as metal, and is electrically connected to the vehicle C. Furthermore, the grounding portion 51 can be integrally formed with the vehicle C or it can be a separate component from the vehicle C. In this embodiment, the height of the grounding portion 51 from the bottom surface of the recess R is specified to achieve the desired characteristics of the antennas 5 and 6.

[0045] Element 52 is a rod-shaped conductor that operates as a vertically polarized wave monopole antenna for V2X communication and extends upward from the substrate 54. Element 52 is positioned approximately at the center in the width direction of the vehicle C.

[0046] Alternatively, the upward length of element 52 can be further extended, thereby making element 52 into a shape that causes the roof panel C1 to bulge upward in a manner located below the roof panel C1 of vehicle C.

[0047] Reflector 53 is a rod-shaped conductor located near element 52 and mounted in a manner that extends upward from substrate 54. Reflector 53 is a passive element that functions as a so-called reflector and has the function of improving the gain of antenna 5 in front of vehicle C.

[0048] (Antenna 6) Antenna 6 is a patch antenna located to the left of antenna 5. Antenna 6 is used for GNSS (Global Navigation Satellite System) and is designed to receive GNSS signals in a manner that allows it to operate within GNSS frequency bands. These bands may include, for example, L1 (center frequency: 1575.42MHz), L2 (center frequency: 1227.60MHz), or L5 (center frequency: 1176.45MHz).

[0049] like Figure 7A As shown, antenna 6 has a flat dielectric 61 disposed on ground portion 51 and positioned to the left of antenna 5, and a radiating element 62 disposed on the upper part of dielectric 61. Antenna 6 functions as a patch antenna and is disposed on the upper surface of ground portion 51.

[0050] Furthermore, the grounding portion 51 can be integrally formed as described above, or it can be divided into two or more parts and grounded separately in antenna 5 and antenna 6.

[0051] The dielectric 61 is formed of a dielectric material such as ceramic. The radiating element 62 responds to radio waves in the L1, L2, and L5 frequency bands. Furthermore, it is not limited to this configuration; it can also be a patch antenna with various configurations, such as a stacked patch antenna, a patch antenna resonating with radio waves in multiple frequency bands, a patch antenna formed of a metal plate without using a dielectric material, or a patch antenna composed of combinations thereof. Furthermore, passive elements for adjusting the elevation direction can be arranged above or around these patch antennas.

[0052] (Grounding part 9) like Figure 3 , Figure 5 , Figure 6 As shown, when viewed from above, the grounding part 9 is formed by a generally rectangular component. The grounding part 9 is electrically and mechanically connected to the vehicle C via screws or other connecting parts, functioning as a grounding component for antennas 2, 3, and 4 of the antenna device 1A. However, the grounding part 9 can also function as a grounding component for only a portion of antennas 2, 3, and 4. For example, grounding part 9 can function as a grounding component for antenna 2, while other grounding parts can function as grounding components for antennas 3 and 4. The grounding part 9 can be connected to the vehicle C not only using connecting parts but also by welding, bonding, or other methods.

[0053] In addition, in this embodiment, such as Figure 5 As shown, the grounding portion 9 is formed as a single metal plate (sheet metal). However, the grounding portion 9 can also be composed of multiple separate metal plates. For example, the grounding portion 9 can also be configured to electrically connect the metal plate with antennas 2 and 3 to another metal plate with antenna 4.

[0054] Furthermore, the grounding portion 9 can function as a grounding element for the antenna in the antenna device 1A, and can be formed in a shape other than a plate. Additionally, the grounding portion 9 can be constructed by freely combining metal components and non-metal components, as long as it functions as a grounding element for the antenna in the antenna device 1A. For example, the grounding portion 9 can also be composed of a metal plate and a resin insulator. Furthermore, the grounding portion 9 is constructed from a substrate with a conductor pattern formed on a printed circuit board (PCB).

[0055] (The spacing between antennas 2 and 3) Components 25, 35, etc. Figure 7A and Figure 7B They are arranged at predetermined intervals. This interval is preferably 20 mm for the following reasons.

[0056] Figure 9A and Figure 9BThe diagram shows the relationship between the spacing of elements 25 and 35 (the spacing between adjacent sides) and the resonant frequencies of antennas 2 and 3. It can be seen that when the spacing of elements 25 and 35 is less than 20mm, the resonant frequencies of elements 2 and 3 change significantly, and the designed performance cannot be obtained.

[0057] Figure 10A and Figure 10B The diagram shows the relationship between the spacing of elements 25 and 35 (the spacing between adjacent sides) and the reflection loss of antennas 2 and 3. It can be seen that when the spacing of elements 25 and 35 is less than 20mm, the reflection loss of element 3, in particular, varies greatly, and the designed performance cannot be achieved.

[0058] By making the spacing between elements 25 and 35 larger than 20mm, it is possible to prevent the performance of antennas 2 and 3 from degrading, but this necessitates making antenna device 1A larger. Considering both miniaturizing antenna device 1A as much as possible and maintaining the performance of antennas 2 and 3, it is preferable to set the spacing between elements 25 and 35, i.e., antennas 2 and 3, to 20mm.

[0059] (The spacing between antennas 3 and 4) Figure 11 This illustrates the effect of the configuration of antennas 2 and 3 on the sensitivity of antenna 4. Figure 11 The diagram shows the sensitivity measurement results of antenna 4 in the following cases: antenna 4 alone (No. 1), antenna 2 adjacent to each other (No. 2), antenna 3 adjacent to each other (No. 3), and antennas 2 and 3 adjacent to each other on both sides (No. 4). The spacing between antennas, i.e., between components, is 20 mm.

[0060] like Figure 11 As shown, compared to the case of antenna 4 alone (No. 1), when antennas 2 and 3 are adjacent (No. 4), the sensitivity decrease is approximately fixed at 2 dB. When either antenna 2 or 3 is adjacent (No. 2, 3), the sensitivity decrease of antenna 4 is approximately fixed at 1 dB.

[0061] In this way, if the antenna 4, which is used to handle AM ​​broadcasts, is arranged at a 20mm interval relative to the antennas 2 and 3, there will be no significant performance degradation, and a small antenna device 1A can be realized.

[0062] Considering the configuration order, placing antennas 2 and 3 on either side of antenna 4 also achieves sufficient performance, but... Figure 5 , Figure 7A and Figure 7B As shown, it is preferable to place one of antennas 2 and 3 adjacent to antenna 4.

[0063] (Arrangement of antennas 2, 3 and 4) Considering the arrangement of antennas 2, 3, and 4, as described above, it is preferable to place antenna 4 at the right or left end of the three antennas rather than in the center. Considering the configuration of antennas 2 and 3, it is preferable to place antenna 3, which has a narrower fractional bandwidth than antenna 2, in the center. This is because a larger fractional bandwidth of an antenna results in a greater impact on the resonant frequency based on adjacent antennas. Furthermore, it can be argued that adjusting the frequency characteristics of antenna 3, which has a narrower fractional bandwidth, places less load on the overall device compared to adjusting the frequency characteristics of antenna 2. Additionally, the fractional bandwidth of antenna 3 is 20% (frequency 88MHz to 108MHz), while the fractional bandwidth of antenna 2 is 32% (frequency 174MHz to 240MHz).

[0064] The result of the above considerations is that, Figure 5 , Figure 7A and Figure 7B As shown, antennas 2 and 4 are positioned at the ends of antenna device 1A, while antenna 3 is positioned at the center. With this configuration, antenna device 1A performs well in any corresponding frequency band of antennas 2, 3, and 4.

[0065] (The position of antenna 5) Antenna 5, which serves as a communication antenna for V2X, is preferably positioned approximately at the center of the width direction of vehicle C, as described below.

[0066] Considering vehicle-to-vehicle communication, antenna 5 is preferably directional in the front and rear. Furthermore, antenna 5 can also be configured as two antennas that obtain gain at the front and rear of vehicle C to achieve diversity. Additionally, if antenna 5 is not positioned approximately at the center of the width direction of vehicle C (e.g., at the end of the width direction of vehicle C), the directivity becomes tilted relative to the front-rear direction of vehicle C, resulting in a reduction or ineffectiveness of gain relative to the necessary area. Figure 12B (This indicates the forward directional orientation of vehicle C). Furthermore, by changing the configuration from the end of vehicle C in the width direction to approximately the center of that width direction, it is possible to suppress the tilt of the directional orientation and obtain a left-right symmetrical waveform.

[0067] In contrast, by positioning the element 52 of antenna 5 approximately at the center of the width direction of vehicle C, the directional offset is eliminated in the longitudinal direction, and antenna 5 is able to have approximately symmetrical directional characteristics relative to the left and right directions. Figure 12A : Indicates the forward directionality of vehicle C.

[0068] Furthermore, considering the need to improve the sensitivity of antenna 5, it is preferable that element 52 be positioned as high as possible. Therefore, the base of element 52 is fixed to the upper surface of grounding portion 51 (see reference). Figure 8 ).

[0069] <Other implementations of antenna 5 configuration> exist Figure 7B In this configuration, the antenna 5 element 52 is positioned on the grounding portion 51 at a height higher than the bottom surface of the recess R, but this is not a limitation. For example, as... Figure 13A As shown, element 52 can also be disposed on the protrusion 100 formed from the bottom surface of the recess R upwards. Furthermore, the protrusion 100 is a portion formed by machining a part of the recess R of the vehicle C, and functions as a grounding element. Additionally, in Figure 13A , Figure 13B and Figure 13C For convenience, the roof panel C1 was omitted.

[0070] Additionally, for example, in Figure 13B In this configuration, an insulating spacer 110 and a metal plate-shaped grounding portion 120 supported by the spacer 110 are provided on the bottom surface of the recess R. In this case, the element 52 can be disposed on the grounding portion 120.

[0071] Additionally, element 52 is a monopole antenna operating as a vertically polarized wave for V2X communication, but it is not limited to this. For example, element 130, which operates as a dipole antenna for vertically polarized waves for V2X communication, can be used instead of the monopole element 52. When using such an element 130, as... Figure 13C As shown, it is sufficient to simply place the element 130 on the insulating spacer 140 disposed in the recess R.

[0072] like Figure 7B and Figure 13A , Figure 13B and Figure 13C As shown, when components 52 and 130 are positioned higher than the bottom surface of the recess R, they are less susceptible to interference from other antennas. Therefore, it is possible to prevent a decrease in gain or a deterioration in directivity of components 52 and 130 (i.e., antenna 5 for V2X).

[0073] Furthermore, in this embodiment, units 52 and 130 are units for V2X communication, but they can also be units for other communication standards with frequencies higher than the DAB or FM bands. By placing the unit (antenna) for a frequency band higher than the DAB band at a higher position, the same effect as in this embodiment can be obtained.

[0074] <Relationship between roof panel C1 and antenna> For example, such as Figure 14A As shown, the shape (here, the height) of the grounding portion 51 can also be adjusted so that the upper end of the element 52 is higher than the antenna 2. Even in this case, it is still consistent with... Figure 7BSimilarly, antenna 5 is positioned at a higher elevation, thus achieving better performance. Furthermore, here, element 52 is positioned higher than antenna 2 above the bottom surface of the recess R, although they could also be at the same height. Alternatively, element 52 could be positioned lower than antenna 2 above the bottom surface of the recess R.

[0075] In addition, such as Figure 7B ,and Figure 14A and Figure 14B As shown, the roof panel C1 has an arc-shaped form. Therefore, the distance between the surface of the lower mold of the roof panel C1 and the bottom surface of the recess R is the longest near the center of the vehicle C, and gradually shortens from the center of the vehicle C towards the left and right directions.

[0076] Here, even at a low altitude, the AM band antenna 4 can ensure gain by increasing its length in the left-right direction. Therefore, the AM band antenna 4 is positioned at the end of the vehicle C in the left-right direction (in this case, the right end).

[0077] Furthermore, the fractional bandwidth of antenna 3, which deals with radio waves in the FM band, is narrower than that of antenna 2, which deals with radio waves in the DAB band. Here, for an antenna with a large fractional bandwidth, it is difficult to obtain gain across the entire frequency band without increasing the antenna height. Therefore, in this embodiment, antenna 2, with its larger fractional bandwidth, is positioned on the central side of vehicle C compared to antenna 3.

[0078] In addition, in this embodiment, such as Figure 14A As shown, for example, the heights of antennas 2, 3, and 4 gradually decrease as they move from the center of vehicle C toward the right end of vehicle C. By changing the heights of antennas 2, 3, and 4 in this way, the antenna gain can be increased at various locations. Furthermore, in this embodiment, the heights of antennas 2, 3, and 4 are different, but they could all be the same height.

[0079] Furthermore, in this embodiment, the elements 35 of antenna 3 and 45 of antenna 4 are supported substantially parallel to the grounding portion 9, but this is not a limitation. For example, such as Figure 14B As shown, components 35 and 45 can also be supported at the central side height of vehicle C. Even in this case, the same effect as in this embodiment can be obtained.

[0080] <Configuration of diversity antenna in concave R> In this embodiment, for example in Figure 7B The diagrams of antennas D and E are omitted, but in reality, as shown in the image... Figure 15AAs shown, in the recess R, in addition to antennas 2, 3, and 4, antennas D and E are also configured. For example, as antennas D and E, in order to achieve diversity with antennas 2 and 3, the same antennas as antennas 2 and 3 can be configured to form diversity antennas on the left and right sides of the vehicle. That is, in Figure 15A In the antenna device 10 shown, antennas 2 and 3 are arranged to the right of antenna 5, and antennas D and E are arranged to the left of antenna 5. Furthermore, new communication antennas such as Wi-Fi antennas can also be mounted in the antenna device 10.

[0081] Furthermore, the configuration of antennas 2, 3, and 4, as well as diversity antennas D and E, is not limited to this. For example, it could also be... Figure 15B The configuration shown. That is, in Figure 15B In the antenna device 10 shown, antennas D and 3 are arranged to the right of antenna 5, and antennas E and 2 are arranged to the left of antenna 5. Alternatively, antennas 2, 3, D, and E can also be MIMO antennas if they are communication antennas.

[0082] In summary, embodiments and variations of the present invention have been described with reference to the accompanying drawings. However, these are merely examples of the present invention, and various configurations other than those described above are possible.

[0083] <Effect> In one embodiment, the antenna device 10 has a plurality of antennas 2 and 3 (equivalent to "first antenna" and "second antenna") arranged in a width direction intersecting the travel direction of the vehicle C. Antenna 2 responds to radio waves in the DAB band (equivalent to "first band"). Antenna 3 responds to radio waves in the FM band (equivalent to "second band"), which has a fractional bandwidth narrower than the DAB band.

[0084] Based on the above configuration, the antenna device 10 can suppress the influence on the resonant frequency, can be positioned in a narrow area, and can achieve high performance. Therefore, in this embodiment, multiple antennas 2 and 3 can be appropriately configured. In addition, the load applied to the amplifier can be suppressed relative to the antennas 2 and 3. By including antennas 2 and 3, the antenna device 10 can handle a wide frequency band.

[0085] The vehicle C has an upper surface U and a recess R that is recessed downward from the upper surface U, and the antenna device 10 is disposed in the recess R.

[0086] Based on the above configuration, the influence on the shape and interior space of vehicle C can be suppressed, thereby allowing the antenna device 10 to be installed in vehicle C.

[0087] The antenna device 10 also includes an antenna 4, which responds to radio waves in the intermediate frequency broadcast band and is located on the outside of the antenna 3 in the width direction.

[0088] By adopting the above configuration, the influence on the resonant frequency can be suppressed and high performance can be achieved as a whole for antennas 2, 3, and 4. Furthermore, the overall miniaturization of the antenna device 10 can be realized. Additionally, the load applied to the amplifier can be suppressed relative to antennas 2, 3, and 4.

[0089] Antennas 2, 3, and 4 are spaced apart to prevent interference between them. That is, this can suppress the influence on the resonant frequency.

[0090] At least one of antennas 2, 3, and 4 has a planar element 25, 35, or 45. By configuring antennas 2, 3, and 4 as capacitor-loaded antennas equipped with elements 25, 35, and 45, the antenna height can be reduced, making them compact devices.

[0091] The antenna device 10 also includes a housing 7 that accommodates antennas 2, 3 and 4 to facilitate installation and transport to vehicle C.

[0092] The antenna device 10 also includes an antenna 5 (equivalent to a "vehicle communication antenna"), which is mounted on the vehicle C and located on the central side in the width direction relative to the first antenna, and is capable of communicating with vehicles different from the vehicle C.

[0093] By positioning antenna 5 near the center of vehicle C, antenna 5 can achieve the following: Figure 12A and 12B The good directional properties shown by [examples].

[0094] Antenna 5 is positioned above ground portion 51 (equivalent to "second ground portion") which is located above ground portion 9 (equivalent to "first ground portion") of antennas 2 and 3.

[0095] By placing antenna 5 at a high position, antenna 5 can achieve high sensitivity.

[0096] The antenna device 10 also includes an antenna 6 (equivalent to a "satellite communication antenna"), which is mounted on the vehicle C and disposed on the grounding part 51 to communicate with the satellite.

[0097] In this embodiment, antenna 2 is a DAB antenna and antenna 3 is an FM antenna. Antennas 2 and 3 maintain good receiving sensitivity. Explanation of reference numerals in the attached figures

[0098] 1A, 1B, 10, 500 antenna devices 2-6 antennas 7, 8 Shell 9.51 Grounding Part Components 25, 35, 45, 52, and 130 Vehicle C R concavity.

Claims

1. An antenna device having a plurality of antennas arranged in a width direction intersecting the vehicle's direction of travel, characterized in that, include: The first antenna is designed to respond to radio waves of the first frequency. as well as The second antenna is located outside the first antenna in the width direction of the vehicle and is designed to handle radio waves in a second frequency band with a fractional bandwidth narrower than the first frequency.

2. The antenna device according to claim 1, characterized in that, The vehicle has an upper surface and a recess that extends downward from the upper surface. The antenna device is disposed in the recess.

3. The antenna device according to claim 1 or 2, characterized in that, It also includes an AM antenna, which responds to radio waves in the intermediate frequency broadcast band and is located outside the width direction relative to the second antenna.

4. The antenna device according to claim 3, characterized in that, The first antenna, the second antenna, and the AM antenna are arranged at intervals to prevent interference between the antennas.

5. The antenna device according to claim 3 or 4, characterized in that, At least one of the first antenna, the second antenna, and the AM antenna has a planar element.

6. The antenna device according to any one of claims 3 to 5, characterized in that, It also includes a housing that accommodates the first antenna, the second antenna, and the AM antenna.

7. The antenna device according to any one of claims 1 to 6, characterized in that, It also includes a vehicle communication antenna mounted on the vehicle, located at the center of the width direction relative to the first antenna, and capable of communicating with vehicles different from the vehicle.

8. The antenna device according to claim 7, characterized in that, The vehicle communication antenna is positioned above the first ground portion where the first antenna and the second antenna are positioned.

9. The antenna device according to claim 8, characterized in that, It also includes a satellite communication antenna, which is mounted on the vehicle, configured at the second grounding part, and communicates with the satellite.

10. The antenna device according to any one of claims 1 to 9, characterized in that, The first antenna is a DAB antenna, and the second antenna is an FM antenna.

11. An antenna comprising one antenna in an antenna apparatus having a plurality of antennas arranged in the vehicle along a width direction intersecting the vehicle's direction of travel, characterized in that, The antenna is located outside the vehicle in the width direction relative to the first antenna that responds to the first frequency radio wave, and responds to the second frequency band radio wave with a fractional bandwidth narrower than the first frequency.

12. A vehicle that mounts a plurality of antennas arranged along a width direction intersecting with respect to the vehicle's direction of travel, characterized in that, A first antenna for responding to radio waves of a first frequency and a second antenna for responding to radio waves of a second frequency band with a fractional bandwidth narrower than the first frequency are mounted from the center outward in the width direction of the vehicle in the order of the first antenna and the second antenna.

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