Patent Grant
12009582
The present disclosure relates to an antenna module and a vehicle roof with an antenna module.
Patent Document 1 discloses a roof module including a chassis, an antenna, a metal panel, and a module substrate integrated with each other.
An obstacle to radio wave is provided around a roof module in some cases. Improvement of a propagation environment of the radio wave is desired.
Thus, an object of the present disclosure is to improve a communication environment by radio wave in an antenna module.
An antenna module according to the present disclosure includes: a substrate; at least one first communication antenna by a frequency band belonging to a first frequency range; and at least one second communication antenna by a frequency band belonging to a second frequency range higher than the first frequency range, wherein the at least one first communication antenna and the at least one second communication antenna are provided on the substrate, and the at least one first communication antenna is provided in a position closer to an edge of the substrate than the at least one second communication antenna.
According to the present disclosure, a communication environment by radio wave in an antenna module is improved.
Embodiments of the present disclosure are listed and described firstly.
An antenna module according to the present disclosure is as follows.
Specific examples of an antenna module and a vehicle roof with an antenna module according to the present disclosure are described hereinafter with reference to the drawings. The present disclosure is not limited to these examples, but is indicated by claims, and it is intended that meanings equivalent to claims and all modifications within a scope of claims are included.
An antenna module and a vehicle roof with an antenna module according to an embodiment is described hereinafter.
The vehicle 10 to which the antenna module 20 is assembled includes a body 12. The body 12 is a part forming an outline of the vehicle 10. The body 12 may be a monocoque body or a body mounted on a ladder type frame. The body 12 includes a vehicle roof part 13. The vehicle roof part 13 is a pan provided on an upper side of a vehicle interior. The vehicle roof part 13 may be formed integrally with the other part of the body 12. The vehicle roof part 13 may have a configuration of being separated from the other part of the body 12 and attached to the other part of the body 12.
The vehicle roof part 13 may be formed by metal or resin. The vehicle roof part 13 is formed by a metal plate herein. The vehicle roof part 13 shields radio wave. The vehicle roof part 13 may be made of resin. In this case, a radio wave shielding layer may be provided in the vehicle roof part 13. The radio wave shielding layer may be a part formed of metal such as aluminum or iron. The radio wave shielding layer may be a layer having a selective radio wave shielding property such as a known frequency selective surface (FSS).
A case where the vehicle roof part 13 is formed by metal or a case where the radio wave shielding layer is provided in the vehicle roof part 13 is an example of the vehicle roof to be an obstacle to the radio wave of at least a part of frequency band.
An opening 13a is formed in the vehicle roof part 13. Herein, the opening 13a is formed closer to a back side in the vehicle roof part 13. The opening 13a is located in a center in a vehicle width direction. A front-back direction is a front-back direction with respect to the vehicle 10, a forward traveling direction of the vehicle 10 is a front side, and a backward traveling direction thereof is a back side. A right-left direction is based on a state of being directed to the front side of the vehicle 10. The right-left direction is also a width direction. An up-down direction is an up-down direction with respect to the vehicle 10. The opening may be located closer to the front side of the vehicle 10, or may be located closer to one lateral side.
The antenna module 20 is fitted into the opening 13a. A member made up of the opening 13a into which the antenna module 20 is fitted in the vehicle roof part 13 can be considered a vehicle roof with an antenna module 70.
The antenna module 20 includes a substrate 22 and a plural types of antennas 31, 32, 33, 34, and 35.
The substrate 22 includes an insulation plate. The substrate 22 may be a metal plate not including the insulation plate. The substrate 22 may be a composite plate of an insulation plate and a metal plate. The plural types of antennas 31, 32, 33, 34, and 35 are provided on a surface on a front side (vehicle exterior side) of the substrate 22. A conductive layer as a ground is formed by a metal foil, for example, on a surface of a back side (vehicle interior side) of the insulation plate.
The plural types of antennas 31, 32, 33, 34, and 35 are communication antennas by a frequency band different from each other. The communication herein includes interactive communication and one-way communication. Each of the antennas 31, 32, 33, 34, and 35 may be a planar antenna or an antenna having a three-dimensional structure.
An antenna in the plural types of antennas 31, 32, 33, 34, and 35 performing communication by a highest frequency band is defined as the communication antenna 31. In this case, the communication antenna 31 is provided in a position with a largest distance D1 from the edge of the substrate 22 in the plural types of antennas 31, 32, 33, 34, and 35.
An antenna in the plural types of antennas 31, 32, 33, 34, and 35 performing communication by a lowest frequency band is defined as the communication antenna 35. The communication antenna 35 is provided in a position with a smallest distance D5 from the edge of the substrate 22 in the plural types of antennas 35, 32, 33, 34, and 35.
A distance from the antennas 31, 32, 33, 34, and 35 to the edge of the substrate 22 indicates a smallest distance from an outer edge part of the antennas 31, 32, 33, 34, and 35 to an outer edge part of the substrate 22.
Assumed as more specific examples of the antennas 31, 32, 33, 34, and 35 are an antenna for performing communication with a wireless base station in a public communication line or a private communication line, an antenna for vehicle-and-vehicle communication or road-and-vehicle communication, or an antenna for receiving a GPS signal. For example, the antenna 31 is a communication antenna by 28 GHz band. The antenna 31 is provided in a position closer to one short side in relation to a center of the substrate 22. A distance from the antenna 31 to the edge of the substrate 22 is D1. The antenna 32 is a communication antenna by 5.8 GHz band. The antenna 32 is provided in a position close to one corner in the substrate 22. A distance from the antenna 32 to the edge of the substrate 22 is D2. The antenna 33 is a communication antenna by 5 GHz band. The antenna 33 is provided in a position in a middle part of the substrate 22 in a long-side direction and close to one long side thereof. The antenna 33 is a diversity antenna, thus a plurality of (two herein) antennas 33 are illustrated. A distance from the antenna 33 to the edge of the substrate 22 is D3. The antenna 34 is a communication antenna by 1.5 GHz band. The antenna 34 is provided in a position close to the other one corner in the substrate 22. A distance from the antenna 34 to the edge of the substrate 22 is D4. The antenna 35 is a communication antenna by 760 MHz band. The antenna 35 is provided in a position in a middle part of the substrate 22 in the long-side direction and close to the other one long side thereof. A distance from the antenna 35 to the edge of the substrate 22 is D5.
Assuming the frequency bands described above, the antenna 31 is a communication antenna for performing communication by a highest frequency band (28 GHz). The distance D1 from the antenna 31 to the edge of the substrate 22 is larger than the other distances D2, D3, D4, and D5. That is to say, the antenna 31 for the highest frequency band is located farther away from the edge of the substrate 22 than the other antennas 32, 33, 34, and 35.
The antenna 35 is a communication antenna for performing communication by a lowest frequency band (760 MHz band). The distance D5 from the antenna 35 to the edge of the substrate 22 is smaller than the other distances D1, D2, D3, and D4. That is to say, the antenna 35 for the lowest frequency band is located closer to the edge of the substrate 22 than the other antennas 31, 32, 33, and 34.
The distances D2, D3, and D4 from the antennas 32, 33, and 34 for the frequency bands between the highest frequency band and the lowest frequency band to the edge of the substrate 22 is smaller than the distance D1 described above and larger than the distance D5 described above. That is to say, the antennas 32, 33, and 34 for the middle frequency bands are located closer to the edge of the substrate 22 than the antenna 31, and located farther away from the edge of the substrate 22 than the antenna 35.
The distance from each of the antennas 32, 33, and 34 for the middle frequency bands to the edge of the substrate 22 is not particularly limited. As an example, the distance from each of the antennas 32, 33, and 34 to the edge of the substrate 22 may be increased as the frequency band of each of the antennas 32, 33, and 34 gets higher. For example, the frequency band of the antenna 32 (5.8 GHz band) is higher than the frequency band of the antenna 33 (5 GHz band). The frequency band of the antenna 33 (5 GHz band) is higher than the frequency band of the antenna 34 (1.5 GHz band). In such a case, the distance D2 from the antenna 32 to the edge of the substrate 22 may be larger than the distance D3 from the antenna 33 to the edge of the substrate 22. The distance D3 from the antenna 33 to the edge of the substrate 22 may be larger than the distance D4 from the antenna 34 to the edge of the substrate 22.
In the present embodiment, the substrate 22 and the antennas 31, 32, 33, 34, and 35 are housed in the case 40. The case 40 is formed of resin, for example. The case 40 is formed into a flat rectangular parallelepiped shape. The substrate 22 is housed in the case 40 in a state where four sides of the peripheral edge part of the substrate 22 face four sides of a peripheral wall of the case 40. A flange part 41 protrudes from a lower side part of the case 40 toward an outer periphery.
The flange part 41 can have contact with the edge of the opening 13a from a side of the vehicle interior while the antenna module 20 is fitted into the opening 13a of the vehicle roof part 13. Accordingly, the positioning of the antenna module 20 with respect to the vehicle roof part 13 is performed. In this state, an outward surface of the antenna module 20 may be flush with an outward surface of the vehicle roof part 13, or may protrude from the outward surface of the vehicle roof part 13.
When the enclosure 50 described above is provided around the antenna module 20, the enclosure 50 can shield radio wave radiated from or to the antennas 31 and 35. Particularly, when the antennas 31 and 35 are located in positions not protruding from the enclosure 50 but deviating to an inner side, the radio wave radiated from the antennas 31 and 35 is radiated to an upper side and an obliquely upper side to some degree, but is hardly radiated directly at an angle close to a horizontal direction.
In the present embodiment, the antenna 35 performing communication by the lowest frequency band in the plural types of antennas 31, 32, 33, 34, and 35 is provided in a position with a smallest distance D5 from the edge of the substrate 22. The enclosure 50 is located in the outer periphery of the substrate 22, thus the antenna 35 is located relatively close to the enclosure 50. Radio wave W1 of a low frequency band is relatively diffracted easily. Thus, even when the antenna 35 is provided near the enclosure 50, the radio wave W1 radiated from the antenna 35 can be diffracted and propagated.
The antenna 31 performing communication by the highest frequency band in the plural types of antennas 31, 32, 33, 34, and 35 is provided in a position with a largest distance D1 from the edge of the substrate 22. The enclosure 50 is located in the outer periphery of the substrate 22, thus the antenna 35 is located relatively far away from the enclosure 50. Radio wave W2 of the high frequency band has high rectilineability. However, the antenna 35 is relatively far away from the enclosure 50, thus the radio wave W2 of the high frequency band is also radiated at an angle relatively close to horizon.
According to the antenna module 20 and the vehicle roof with the antenna module 70 having the above configurations, the communication antenna 31 by the highest frequency band in the plural types of antennas 31, 32, 33, 34, and 35 is provided in the position farthest away from the edge of the substrate 22. Accordingly, even if an obstacle (for example, the enclosure 50) to the radio wave is located around the antenna module 20, the radio wave W2 of the highest frequency band is hardly shielded by the obstacle but can be radiated to a surrounding area at an angle as close to horizon as possible. As a result, communication can be favorably performed via the communication antenna 31 by the highest frequency band. The communication antenna 35 by the highest frequency band in the plural types of antennas 31, 32, 33, 34, and 35 is provided in the position closest to the edge of the substrate 22. Even if an obstacle to radio wave (for example, the enclosure 50) is located around the antenna module 20, the radio wave W1 in the lowest frequency band is diffractively propagated easily. As a result, communication can also be favorably performed via the communication antenna 35 by the lowest frequency band. According to these configurations, a communication environment by radio wave in the antenna module 20 is improved.
Particularly, in the case where the enclosure 50 which is the obstacle to the radio wave is disposed around the substrate 22, a communication environment by radio wave in the antenna module 20 is effectively improved.
When the obstacle is the vehicle roof part 13, the vehicle roof part 13 can shield the radio wave of at least a part of frequency band at the inner side and the outer side of the vehicle. In this case, the antenna module 20 is fitted into the opening 13a of the vehicle roof part 13, thus the antennas 31, 32, 33, 34, and 35 can favorably perform communication with an external apparatus.
In this case, the vehicle roof part 13 may be an obstacle to the radio wave. However, as described above, the communication antenna 31 by the highest frequency band is provided to be farthest away from the edge of the substrate 22, and the communication antenna 35 by the lowest frequency band is provided to be closest to the edge of the substrate 22. Thus, a communication environment by radio wave in the antenna module 20 is improved.
Described in the above embodiment is the example that the communication antenna 31 by the highest frequency band is provided in the position farthest away from the edge of the substrate 22, and the communication antenna 35 by the lowest frequency band is provided in the position closest to the edge of the substrate 22.
However, the configuration is not limited to the above example, but a communication environment by radio wave in the antenna module 20 can be improved.
For example, it can also be considered that the antenna module 20 includes: a substrate 22; at least one first communication antenna by a frequency band belonging to a first frequency range; and at least one second communication antenna by a frequency band belonging to a second frequency range higher than the first frequency range, wherein the at least one first communication antenna and the at least one second communication antenna are provided on the substrate 22, and the at least one first communication antenna is provided in a position closer to an edge of the substrate 22 than the at least one second communication antenna.
In this case, it is applicable that the first frequency range is a frequency band equal to or smaller than 2.1 GHz, and the second frequency range is a frequency band equal to or larger than 5.7 GHz. The first frequency band may be equal to or larger than 200 MHz and equal to or smaller than 2.1 GHz. The second frequency range may be equal to or larger than 5.7 GHz and equal to or smaller than 40 GHz.
As exemplified above, the antenna 31 is the communication antenna by 28 GHz band, the antenna 32 is the communication antenna by 5.8 GHz band, the antenna 33 is the communication antenna by 5 GHz band, the antenna 34 is the communication antenna by 1.5 GHz band, and the antenna 35 is the communication antenna by 760 MHz band. In this case, the at least one first communication antenna is the antenna 34 and the antenna 35. The at least one second communication antenna is the antenna 31 and the antenna 32. The antenna 33 is the antenna which does not fall under any of the first communication antenna and the second communication antenna.
The antennas 34 and 35 which are the at least one first communication antenna (the distances from the edge are D4 and D5, respectively) are provided in the positions closer to the edge of the substrate 22 than the antennas 31 and 32 which are the at least one second communication antenna (the distances from the edge are D1 and D2, respectively) (that is to say, D4 and D5 are smaller than D1 and D2).
Even in this case, the at least one second communication antenna 31 and/or 32 by the frequency band belonging to the second frequency range higher than the first frequency range is provided in the position farther away from the edge of the substrate 22 than the at least one first communication antenna 34 and/or 35. Thus, even if an obstacle to radio wave is located around the antenna module 20, radio wave from the at least one second communication antenna 31 and/or 32 is hardly shielded by the obstacle. The at least one first communication antenna 33 and/or 34 by the frequency band belonging to the first frequency range is provided in the position closer to the edge of the substrate than the at least one second communication antenna 31 and/or 32. Even if an obstacle to radio wave is located around the antenna module 20, radio wave of a relatively low frequency band is diffractively propagated easily. As a result, a communication environment by radio wave in the antenna module 20 is improved.
For example, it is considered that an antenna for a wireless lock-unlock system (keyless system, for example) of automobiles is for 315/433 MHz, an antenna for intelligent transport systems (ITS) in Japan is for 755 to 765 MHz, an antenna for mobile communication (for example, long term evolution (LTE)) is for 0.8/1.5/1.7/2 GHz, an antenna for remote start is for 920 MHz, an antenna of global navigation satellite system (GNSS) and GPS is for 1.57542 GHz, an antenna for a satellite radio is for 2.32 to 2.35 GHz, an antenna for Bluetooth (trademark) or Wi-Fi (trademark) is for 2.4/5 GHz, an antenna for mobile communication (for example, 5G Sub6) is for 3.6 to 4.1 GHz/4.5 to 4.6 GHz (in Japan), an antenna of Japanese electronic toll collection system (ETC) is for 5.8 GHz, an antenna of U.S. intelligent transport systems (ITS) is for 5.9 GHz, and an antenna for mobile communication (for example, 50 millimeter wave) is for 28 GHz/26 GHz/39 GHz. In a case where the plurality of antennas of them are provided on the same substrate, the plurality of antennas may be separated by the first frequency band and second frequency band to be disposed on the substrate 22 as described above.
As illustrated in
Examined under the above condition are an arrangement 1, an arrangement 2, an arrangement 3, an arrangement 4, and an arrangement 5 in which the arrangement positions of the antennas 131, 132, 133, and 134 are changed. The arrangement positions of the antennas 131, 132, 133, and 134 in the arrangements 1 to 5 are illustrated in
As already exemplified above, when the first frequency range is the frequency band equal to or smaller than 2.1 GHz and the second frequency range is the frequency band equal to or larger than 5.7 GHz, the antennas 131 and 132 are the first antennas, the antenna 133 is the second antenna, and the antenna 134 is not any of the first antenna and the second antenna. Indicated in any of the arrangements 1 to 5 illustrated in
A simulation result of the Return loss [dB] and the gain Ave for each of the arrangements 1 to 5 is illustrated in
The simulation result shows that a favorable result is obtained for the Return loss [dB] and the gain Ave in the case of the arrangement 4. In the case of the arrangement 4, a difference between a distance from the center of the substrate 122 to the first antennas 131 and 132 and a distance from the center of the substrate 122 to the second antenna 133 can be increase. Thus, the result shows that such an arrangement is appropriate for clearly sectioning the arrangement position in that the first antennas 131 and 132 are disposed as close to the center of the substrate 122 as possible and the second antenna is disposed as close to the edge of the substrate 122 as possible. For example, the first antenna may be provided in a position in which a distance from the center of the substrate to a center of the antenna is 20 cm to 90 cm, and preferably in a position in which the distance is approximately 20 cm. The second antenna may be provided in a position in which a distance from the center of the substrate to a center of the antenna is 75 cm to 90 cm, and preferably in a position in which the distance is approximately 70 cm.
Each configuration described in the embodiments and modification examples thereof can be appropriately combined as long as they are not contradictory.
The present disclosure includes an antenna module described hereinafter.
The present disclosure includes a vehicle roof with an antenna module described hereinafter.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-129835 | Jul 2019 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/026832 | 7/9/2020 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2021/010274 | 1/21/2021 | WO | A |
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| Office Action issued in Corresponding JP Patent Application No. 2021-533013, dated Aug. 2, 2022, along with an English translation thereof. |
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| Number | Date | Country | |
|---|---|---|---|
| 20220271421 A1 | Aug 2022 | US |
