Antenna Complex

Abstract

To provide an antenna composite body capable of suitably providing the characteristics of different types of antennas with a simple structure.SOLUTION: A antenna composite body according to the present disclosure includes two or more types of antennas of different frequency bands, and the two or more types of antennas include a first antenna of a relatively high frequency band, and a second antenna in a relatively low frequency band combined with the first antenna, and each of the first antenna and the second antenna has a single feed portion and share a single ground.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an antenna complex. [Background technology]

[0002] BACKGROUND ART Antennas of various shapes are used in information communication devices that transmit and receive information by radio signals (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-259048 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been an increasing demand for antennas with security functions in addition to radio wave transmission and reception functions. To meet this demand, it is possible to use two types of antennas with different frequency bands. When using inverted-F antennas with one power feed point and one ground point for each antenna, it is necessary to adjust the positions of the two ground points and two power feed points to suppress radio wave interference between the antennas and to match impedance.

[0005] In view of the above circumstances, an object of the present disclosure is to provide an antenna complex that has a simple structure and is capable of providing the characteristics of different types of antennas in an optimal manner. [Means for solving the problem]

[0006] In order to achieve the above object, the present disclosure provides: Equipped with two or more types of antennas with mutually different frequency bands, the two or more antennas include a first antenna of a relatively high frequency band and a second antenna of a relatively low frequency band combined with the first antenna; An antenna complex is provided in which the first antenna and the second antenna each have a single feed and share a single ground with each other. [Effects of the Invention]

[0007] The antenna complex of the present disclosure is capable of providing the optimal characteristics of different types of antennas with a simple structure. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view illustrating an antenna complex according to an embodiment of the present disclosure when viewed from a predetermined direction. [Figure 2] FIG. 2 is a schematic perspective view of an antenna complex according to an embodiment of the present disclosure, as viewed from another direction. [Figure 3] FIG. 3 is a schematic perspective view illustrating an antenna complex according to another embodiment of the present disclosure when viewed from a predetermined direction. [Figure 4] FIG. 4 is a schematic perspective view illustrating an antenna complex according to another embodiment of the present disclosure, as viewed from another direction. [Figure 5] FIG. 5 is a graph showing the relationship between frequency and VSWR in the second antenna. [Figure 6] FIG. 6 is a graph showing the relationship between frequency and VSWR in the first antenna. [Figure 7] FIG. 7 shows the radiation pattern (directional gain) of the second antenna. [Figure 8] FIG. 8 shows the radiation pattern (directional gain) of the first antenna. [Figure 9] FIG. 9 is a schematic perspective view illustrating a surface-mounted antenna complex of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] The antenna complex of the present disclosure will now be described with reference to the drawings.

[0010] Fig. 1 is a schematic perspective view showing an antenna complex according to an embodiment of the present disclosure as viewed from a predetermined direction, and Fig. 2 is a schematic perspective view showing an antenna complex according to an embodiment of the present disclosure as viewed from another direction.

[0011] 1 and 2, an antenna complex 500 according to an embodiment of the present disclosure combines two types of antennas 100 operating in different frequency bands. The two types of antennas 100 are a first antenna 110 operating in a relatively high frequency band and a second antenna 120 operating in a relatively low frequency band combined with the first antenna 110. Although FIGS. 1 and 2 illustrate two types of antennas 100, the present disclosure is not limited to this and two or more types of antennas may be combined.

[0012] The first antenna 110 includes a first main body 111, a first feed portion 112, and a ground portion G, which each extend in a different direction relative to the longitudinal extension direction of the first main body. The second antenna 120 includes a second main body 121, a second feed portion 122, and a ground portion G, which each extend in a different direction relative to the longitudinal extension direction of the second main body. The ground portion G is a single ground portion shared between the first antenna 110 and the second antenna 120.

[0013] For the above reasons, in the present disclosure, each antenna 100 includes a main body, a single feed portion, and a single ground portion G, each extending in a different direction relative to the longitudinal extension direction of the main body. Furthermore, in the present disclosure, each antenna 100 can share the single ground portion G with another antenna.

[0014] In this disclosure, the term "antenna complex" refers to two or more types of antennas combined into one. In this disclosure, "two or more types of antennas" refers to antennas of different types (types) and does not include antennas of the same type (e.g., Bluetooth antennas). In this disclosure, the term "antenna" refers to a component, apparatus, or device that can convert electric current into radio waves or electromagnetic waves, or vice versa. In addition, the term "antenna" in this disclosure may be a monopole antenna.

[0015] In the present disclosure, the "feed point" of an antenna refers to a point to which power or electrical energy can be supplied from an external structure. There are no particular limitations on the shape of the feed point. The feed point preferably has a plate-like shape. The feed point is preferably connected to, for example, a power feed line or power supply wiring of an electronic circuit board. The feed point preferably has a shape that follows the surface shape of the board at the contact point with the electronic circuit board. The feed point may or may not have a single plate-like shape.

[0016] In this disclosure, the term "ground portion" refers to a point or portion that can contact an external structure to form a ground (GND). The ground portion can be connected to, for example, the GND layer or GND wiring of an electronic circuit board. It is preferable that the ground portion has a shape that conforms to the surface shape of the electronic circuit board at the contact portion with the electronic circuit board. The ground portion may or may not be in the shape of a single plate.

[0017] When using antennas each having one power supply and one independent grounding point, it may be necessary to adjust the positions of the two grounding points and the two power supply points in order to suppress radio wave interference between the antennas and to match impedance.

[0018] In contrast, in the present disclosure, each antenna 100 can share a single ground portion G with each other. That is, the ground portion G functions as a shared ground portion. This allows for a simpler structure than when each antenna has one feed portion and one independent ground portion. As a result, the size of the antenna complex 500 can be reduced. That is, the antenna complex 500 can be made more compact.

[0019] The realization of a simple structure reduces the number of grounding parts that require position adjustment by one, and the target impedance can be adjusted by adjusting the positions of the two power supply parts 100 (corresponding to adjusting the distance between the two power supply parts) and the single grounding part G. As a result, impedance matching can be easily adjusted.

[0020] Furthermore, in the present disclosure, even when the antenna complex 500 has a simple structure with a single grounding portion G (corresponding to a shared grounding portion) as described above, resonance of a given antenna with other antennas is suppressed during use, i.e., radio wave interference between the antennas can be suppressed. This allows the antenna characteristics of each antenna 100 to be stabilized. In other words, in the present disclosure, the antenna characteristics of each antenna 100 can be optimally provided.

[0021] For the above reasons, the antenna complex of the present disclosure is small and has more stable antenna characteristics, and therefore can be installed in vehicles such as automobiles, hybrid vehicles, and electric vehicles, electronic devices such as smartphones and wearable devices, or can be used for communication with these electronic devices.

[0022] Furthermore, since the antenna complex of the present disclosure can be miniaturized, it can be placed and used on circuit boards inside vehicle computers, particularly ECUs (engine control units), smartphones, and wearable devices.

[0023] In this disclosure, "antenna characteristics" refers to antenna characteristics in general, specifically radiation patterns such as directional gain, and impedance. In this disclosure, "stabilization" of antenna characteristics means that the antenna characteristics do not fluctuate significantly. For example, when the antenna characteristics are radiation patterns, stabilization of antenna characteristics means that the antenna is omnidirectional, and particularly when the antenna characteristics are directional gain, it means that the antenna has a radiation pattern whose outline is nearly a perfect circle on the XY plane.

[0024] When the antenna characteristic is impedance, stabilizing the antenna characteristic means, for example, stably exhibiting a target impedance in a desired or required frequency band. In the present disclosure, it is preferable that each antenna 100 forms a predetermined bandwidth that includes the target impedance.

[0025] In the present disclosure, each antenna 100 may be an inverted-F antenna. In this case, each feed point and the single ground point are spaced apart from each other. With this configuration, the feed points of each antenna can be mounted to the corresponding electronic circuit board by soldering or the like, and the single ground point can be grounded to a specific electronic circuit board or other structure. Furthermore, with an inverted-F antenna, each feed point and the ground point can be positioned on the same plane. This may enable horizontal omnidirectionality to be achieved. Note that, in this specification, "on the same plane" refers to the positional relationship between each feed point and the ground point being on approximately the same plane or in approximately the same row along a specific direction, but does not require each feed point and the ground point to be completely physically on the same plane.

[0026] This allows each antenna 100 to be used as a surface-mounted product. In this disclosure, the term "surface-mounted product" refers to a component or member that can be mounted on a substrate, such as an electronic circuit board, using surface-mount technology (SMT) known in the art. A "surface-mounted product" may also be referred to as a surface-mounted device (SMD).

[0027] As described above, in the present disclosure, the first antenna 110 is an antenna for a relatively high frequency band, and the second antenna 120 is an antenna for a relatively low frequency band. In one example, the first antenna 110 may be an antenna for a frequency band of 3 GHz or more and 13 GHz or less, preferably 6 GHz or more and 13 GHz or less, and more preferably 6 GHz or more and 8 GHz or less (which may be referred to as ultra wide band (UWB)). In another example, the second antenna 120 may be an antenna for Bluetooth in a frequency band of 2 GHz or more and less than 3 GHz, preferably 2.4 GHz or more and 2.5 GHz or less.

[0028] With this configuration, first antenna 110 has a high frequency and a short wavelength, and therefore can repeatedly provide pulse waves to a device under test that is located relatively close to antenna complex 500. This allows for accurate measurement of the distance between antenna complex 500 and the device under test (i.e., "ranging").

[0029] Due to the short wavelength characteristics of the first antenna 110, the distance to a target object located relatively far from the antenna complex 500 is not measured. Therefore, the distance measurement allows the security to be deactivated only when the target object is located within a short distance (for example, approximately 1 meter). This effectively prevents the security from being accidentally deactivated when the target object is located far away. By utilizing the above characteristics, when the antenna complex of the present disclosure is disposed on the board of a vehicle's computer, particularly the ECU, the problem of so-called "relay attacks" can be effectively addressed. This makes it possible to prevent vehicle theft.

[0030] On the other hand, the second antenna 120 has a lower frequency and a longer wavelength, so the radio waves generated based on the signal from the module can be used for other suitable communication purposes.

[0031] In addition, in the present disclosure, it is preferable that the bandwidth of the first antenna 110 is wider than the bandwidth of the second antenna 120. A wider bandwidth is advantageous in that it allows for a larger amount of data communication via the antenna and a higher data rate, thereby enabling high-speed communication over short distances (e.g., about 1 meter).

[0032] As described above, comparing the first antenna 110 and the second antenna 120, the first antenna 110 is an antenna with a short wavelength and a wide frequency bandwidth. On the other hand, the second antenna 120 is an antenna with a long wavelength and a narrow frequency bandwidth. Therefore, the first antenna 110 can have a high impedance even without being far from the ground surface G side. On the other hand, the second antenna 120 can have a low impedance if it is close to the ground surface G side, so the above-mentioned impedance value can be achieved by being farther away from the ground surface G side.

[0033] For the above reasons, the first body portion 111 of the first antenna 110 can be provided proximal to the ground portion G, and the second body portion 121 of the second antenna 120 can be provided distal to the ground portion G. In other words, in the height direction (Z direction) of the antenna complex 100, the first body portion 111 can be positioned on the lower side, and the second body portion 121 can be positioned on the upper side.

[0034] In the above frequency band, the first antenna 110 may have an impedance in the range of, for example, 25 Ω to 55 Ω, preferably 45 Ω to 55 Ω, and preferably a target peak impedance value of 50 Ω. By having an impedance value within the above range, the first antenna 110 can support ultra-wideband communications.

[0035] In the above case, the first main body portion 111 and the second main body portion 121 have portions that are spaced apart and facing each other, in order to suppress resonance of the second antenna 120 when the first antenna 110 is in use, and resonance of the first antenna 110 when the second antenna 120 is in use, i.e., in order to suppress radio wave interference between the antennas.

[0036] In order to ensure the minimum necessary path for second antenna 120 to have second power supply portion 122 extending from second body portion 121 and ground portion G, first body portion 111 and second body portion 121 may be locally continuous. In this case, first body portion 111 and second body portion 121 have a U-shaped configuration as a whole.

[0037] Similarly to the above, it is preferable to provide a ground portion G between the first power feeding portion 112 and the second power feeding portion 122 in order to suitably suppress radio wave interference between the antennas.

[0038] From the viewpoint of stable placement of the antenna complex 100, it is preferable that the width of the ground portion G is equal to or greater than the width of each of the feeding portions 112, 122.

[0039] Similarly to the above, in order to appropriately suppress radio wave interference between the antennas and to ensure a distance between the feed portions 112, 122 in order to adjust impedance, it is preferable to make the distance of the continuous portion between the second feed portion 122 and the ground portion G greater than the distance of the continuous portion between the first feed portion 112 and the ground portion G. This configuration can be achieved by varying the size of the cutout areas in the antenna complex 100.

[0040] The antenna complex 500 of the present disclosure is also preferably supportable by a support 600 .

[0041] Such an arrangement of the support 600 can prevent deformation of the antenna complex 500. That is, the shape stability and self-supporting ability of the antenna complex 500 can be improved, and the characteristics of each antenna can be further stabilized.

[0042] There are no particular limitations on the material that constitutes the support 600, but the support may be made of a resin (for example, at least one material selected from the group consisting of polycarbonate (PC), polyphenylene sulfide (PPS), polyamide (PA), syndiotactic polystyrene (SPS), and liquid crystal polymer (LCP)). By arranging a dielectric, particularly a dielectric with a high dielectric constant, such as a resin dielectric with a high dielectric constant, inside the support, the antenna characteristics of each antenna can be further stabilized.

[0043] There are no particular limitations on the shape of the support 600. For example, the support 600 may have a box shape such as a cube or rectangular parallelepiped, or a square prism shape, depending on the shape of the antenna complex 500. The support 600 may also have other shapes such as a triangular prism, polygonal prism, or cylinder.

[0044] At least one major surface of the support is preferably flat, which can facilitate grounding of the antenna complex 500 of the present disclosure to a plate-like structure, such as an electronic circuit board.

[0045] Figure 3 is a schematic perspective view showing an antenna complex according to another embodiment of the present disclosure when viewed from a predetermined direction, and Figure 4 is a schematic perspective view showing an antenna complex according to another embodiment of the present disclosure when viewed from another direction.

[0046] 3 and 4, the support 600A preferably has a plurality of protrusions 610A at predetermined locations on its surface, and the antenna complex 500A preferably has through-holes 510A that can engage with the respective protrusions 610A of the support 600A.

[0047] This configuration improves the connection between the antenna complex 500A and the support 600A, thereby more effectively preventing deformation of the antenna complex 500. As a result, the shape stability and self-supporting ability of the antenna complex 500 can be further improved, and the characteristics of each antenna can be further stabilized.

[0048] In the present disclosure, the support is not an essential component. For example, if the feeder of the first antenna and the feeder of the second antenna are arranged so as to be spaced apart and face each other, the antenna complex can stand on its own without using a support.

[0049] Furthermore, each antenna 100 is preferably made of a conductor. Examples of conductors include metals and / or alloys. Examples of metal elements that can be contained in the metals and / or alloys include copper (Cu), aluminum (Al), iron (Fe), and zinc (Zn). It is preferable to use at least one material selected from the group consisting of copper, aluminum, stainless steel, and brass (sometimes called brass). It is particularly preferable that the antenna 100 be made of brass.

[0050] When the antenna 100 is made of a material such as a metal and / or alloy, it may further have a plating layer or a surface treatment layer, which preferably contains an element such as chromium or nickel.

[0051] The antenna 100 may be made of ceramic or the like. As the ceramic, ceramic with a high dielectric constant is preferable. For example, dielectric ceramic that can be used for chip antennas or the like can be used without particular limitation. The antenna may be made of a composite material of metal and ceramic or the like.

[0052] Although not particularly limited, the antenna complex 500 of the present disclosure has a width dimension of 5 mm to 50 mm, preferably 10 mm to 20 mm, for example, 12 to 13 mm. The antenna complex 500 of the present disclosure has a height of 5 mm to 30 mm, preferably 8 mm to 15 mm, for example, 10 mm. The antenna complex 500 of the present disclosure has a height of 3 mm to 30 mm, preferably 5 mm to 15 mm, for example, 7 mm. The antenna complex 500 of the present disclosure has a thickness of, for example, 1 mm or less, preferably 0.5 mm or less, and more preferably 0.1 mm to 0.4 mm. The thickness may or may not be uniform overall. [Example]

[0053] Hereinafter, examples of the present disclosure will be described.

[0054] An antenna complex having the following configuration was prepared: The prepared antenna complex 500A was surface-mounted on a substrate 700 (see FIG. 9). ■ First antenna Frequency bands between 6GHz (6000MHz) and 8.5GHz (8500MHz) 1 power supply ■ Second antenna Frequency bands between 2.4GHz (2400MHz) and 2.5GHz (2500MHz) 1 power supply ■Common features of the first and second antennas Shared single ground contact

[0055] Measurement result 1 (relationship between frequency and VSWR for each antenna) Fig. 5 is a graph showing the relationship between frequency and VSWR in the second antenna, and Fig. 6 is a graph showing the relationship between frequency and VSWR in the first antenna.

[0056] As shown in Fig. 5, in the second antenna, the VSWR (voltage standing wave ratio: equivalent to the ratio of incident wave to reflected wave in voltage) in the used frequency band (frequency band of 2.4 GHz or more and 2.5 GHz or less) was approximately 2. This shows that the second antenna provides favorable antenna characteristics.

[0057] 6, in the frequency band used (frequency band of 6 GHz or more and 8.5 GHz or less), the VSWR (voltage standing wave ratio: equivalent to the ratio of incident wave to reflected wave in voltage) of the first antenna was approximately 2. This shows that the first antenna provides favorable antenna characteristics.

[0058] Measurement result 2 (radiation pattern (directional gain) of each antenna) Figure 7 shows the radiation pattern (directional gain) of the second antenna, and Figure 8 shows the radiation pattern (directional gain) of the first antenna.

[0059] As shown in Fig. 7, it was found that the second antenna had a radiation pattern in which the contour (XY plane) of the directional gain was nearly a perfect circle in all of the frequency bands used (2400 MHz, 2440 MHz, and 2480 MHz). This shows that the second antenna provides favorable antenna characteristics.

[0060] As shown in Fig. 8, it was found that the first antenna had a radiation pattern in which the external shape (XY plane) of the directional gain was close to a perfect circle in all of the frequency bands used (6000 MHz, 6500 MHz, 7000 MHz, 7500 MHz, 8000 MHz). This shows that the first antenna provides favorable antenna characteristics.

[0061] From the above, it was found that the antenna characteristics of each of the first antenna 110A and the second antenna 120A can be stabilized even when using the antenna complex 500A equipped with a single ground portion G. It was also found that horizontal omnidirectionality can be achieved when the first feed portion 112A of the first antenna 110A, the second feed portion 122A of the second antenna 120A, and the ground portion G are on the same plane.

[0062] There are no particular limitations on the manufacturing method of the antenna composite of the present disclosure. For example, when the antenna composite of the present disclosure is manufactured from a plate-shaped material such as a metal or alloy, it can be manufactured by cutting and bending the plate-shaped material. Alternatively, the plate-shaped material may be cut and the individual components may be joined by welding or the like. When the antenna composite of the present disclosure is manufactured from a dielectric ceramic, it can be manufactured in the same manner as a chip-type ceramic antenna. For example, a dielectric ceramic antenna composite may be formed on a heat-resistant support using a printing technique known in the ceramic field.

[0063] The above describes embodiments of the present disclosure, but the present disclosure is not limited to these, and various modifications based on the knowledge of those skilled in the art are possible, such as combining the above configurations, as long as they do not deviate from the spirit of the claims. [Industrial Applicability]

[0064] The antenna complex of the present disclosure can be mounted on vehicles (e.g., passenger cars, hybrid vehicles, electric vehicles, etc.), electronic devices (e.g., smartphones, wearable devices, etc.) and used for communication, ranging, etc. [Explanation of symbols]

[0065] 100, 100A Antenna 110, 110A First antenna 111, 111A 1st body part 112, 112A First power supply 120, 120A Second antenna 121, 121A 2nd main body 122, 122A Second power supply 500, 500A Antenna Complex 600, 600A support 700 boards G Grounding part

Claims

1. Equipped with two or more types of antennas with mutually different frequency bands, the two or more types of antennas include a first antenna of a relatively high frequency band and a second antenna of a relatively low frequency band combined with the first antenna; the first antenna and the second antenna each have a single feed portion and share a single ground portion; the first antenna and the second antenna are each an inverted-F antenna, An antenna complex, wherein the first antenna has a first body portion disposed proximal to the ground portion, and the second antenna has a second body portion disposed distal to the ground portion.

2. The antenna complex of claim 1 , wherein the bandwidth of the first antenna is wider than the bandwidth of the second antenna.

3. 3. The antenna complex of claim 1, wherein each feed section and the ground section are positioned in the same plane.

4. 4. The antenna complex according to claim 1, wherein each of the feed portions and the ground portion are spaced apart from each other.

5. 5. The antenna complex of claim 1, wherein the width of the ground portion is equal to or greater than the width of the feed portion.

6. The antenna complex according to any one of claims 1 to 5, wherein the first antenna is for a frequency band of 3 GHz or more and 13 GHz or less.

7. The antenna complex of any one of claims 1 to 6, wherein the second antenna is in a frequency band of 2 GHz or more and less than 3 GHz.

8. The antenna complex according to claim 1 , wherein the first body portion is located on a lower level and the second body portion is located on an upper level in a height direction.

9. The antenna complex of claim 1 , wherein the first body portion and the second body portion have spaced apart opposing portions.

10. The antenna complex of claim 1 , wherein the first body portion and the second body portion are locally contiguous.

11. The antenna complex of claim 1 , wherein the first body portion and the second body portion generally form a U-shape.

12. The antenna complex according to any one of claims 1 to 11, wherein the ground portion is provided between the feed portion of the first antenna and the feed portion of the second antenna.

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