The present invention mainly relates to an antenna integrated harness which is mounted on a movable body such as an automobile and is suitable for a wireless device.
For example, in the field of an in-car antenna to be mounted on an automobile, recent advance in a communication network has caused development of various antennas which are suitable for various frequency bands to be used.
For example, car navigation systems are connected with various kinds of antennas which are suitable for transmission and reception of microwaves of 1 GHz to 10 GHz and are used in ITS (Intelligent Transport Systems) such as GPS (Global Positioning System), VICS (Vehicle Information and Communication System: Registered Trademark), and ETC (Electronic Toll Collection).
Further, a car navigation system is generally provided with not only the ITS but also a tuner which receives radio broadcasting and terrestrial digital broadcasting. Accordingly, a band in which an antenna device for a car navigation system is required to operate includes an AM frequency of 526.5 kHz to 1606.5 kHz, a band of 60 MHz, a VHF frequency of 87.5 MHz to 108 MHz, a UHF frequency of 470 MHz to 770 MHz to be used for terrestrial digital broadcasting. Thus, the band covers a wide range.
The terrestrial digital broadcasting makes it possible to provide not only a digital high-definition and high sound quality program but also an interactive program, so that a program in which images are clear without flickering can be viewed even with a television installed in, for example, a running train or bus. Further, it is scheduled to provide a service that allows a mobile information terminal or the like to receive and view a moving image, data broadcasting, or voice broadcasting.
As an antenna for use in a television receiver or a radio receiver for a small portable device, there has been widely known a rod antenna having an extendable structure. The rod antenna is useful, because it can exert its functions when extended and it becomes compact when retracted. As an antenna device using the rod antenna, for example, there has been proposed a device in which (i) a feed pin of a planar antenna is constituted by an extendable rod antenna and (ii) electric connection and disconnection between an extraction conductor of the rod antenna and a patch-shaped conductor of the planar antenna enable the antenna device to serve as a circularly polarized wave antenna and a linearly polarized wave antenna.
Further, there has been known a “helical (coil) antenna” as another arrangement example of the rod antenna. The helical antenna is formed by spirally winding an antenna line around a rod. Generally, an antenna using a conducting wire longer than a wavelength has a wide useable band. Therefore, the helical (coil) antenna can be downsized while keeping its wide-band characteristic by virtue of its winding structure.
According to the helical coil antenna 1100 shown in
The helical coil antenna 1100 of
Note here that it is essential for a wireless device such as a mobile phone, a car navigation system, a dedicated portable television, or a personal computer to be provided with an antenna. However, an antenna having a conventional arrangement varies in performance (directivity, usable band) depending on a place where the antenna is provided. In particular, the antenna deteriorates in performance due to the presence of a conductor (including a wireless device, for example) near the antenna. Therefore, an antenna having a conventional arrangement frequently needs to be provided in a place away from a wireless device. Such a case requires a complicated wiring process for connecting the antenna and the wireless device.
In particular, in the case of an in-car antenna (described earlier), many electronic devices and a harness formed by causing a group of wires extending from the respective electronic devices to be a bundle are provided in a narrow space inside a car body, and it is necessary to further provide an antenna line in the narrow space.
The present invention has been made in view of the problems, and an object of the present invention is to provide an antenna integrated harness which serves as an antenna device and can be easily provided even in a narrow space in a vicinity of a conductor such as a wireless device.
In order to attain the object, a first antenna integrated harness in accordance with the present invention includes: a wire harness formed by bundling a plurality of electric cables; an antenna element which is plate-like and is provided on, while conforming to, a surface of the wire harness; and a feed line connected with the antenna element and bundled with the plurality of electric cables.
In order to attain the object, a second antenna integrated harness in accordance with the present invention includes: a wire harness formed by bundling a plurality of electric cables; a member which can be connected with the wire harness; an antenna element which is plate-like and is provided on, while conforming to, a surface of the member; and a feed line which is connected with the antenna element and which can be bundled with the plurality of electric cables when the member is connected with the wire harness.
Note that “an antenna element which is plate-like and is provided on, while conforming to, a surface of a wire harness” encompasses not only (1) a state in which the antenna element is provided on the surface of the wire harness but also all the following states (described later): (2) a state in which the antenna element is not in direct contact with the surface of the wire harness, i.e., a state in which the antenna element is provided on an outer surface of a dielectric material which is provided on the surface of the wire harness, (3) a state in which the antenna element is provided on an inner surface of a dielectric material provided on, while conforming to, the surface of the wire harness, and (4) a state in which the antenna element is embedded in a dielectric material provided on, while conforming to, the surface of the wire harness.
Note that a “plate-like” plane is not limited to a two-dimensional plane but may be a plane which (i) is obtained by cutting off a part of a curved surface such as a cylindrical surface, a spherical surface, a paraboloid, or a hyperboloid and (ii) has a three-dimensional shape.
Note also that a movable body on which an antenna integrated harness mentioned above is mounted is also included within the scope of the present invention.
An antenna integrated harness of the present invention having the configuration can be easily provided in a vicinity of a conductor such as a wireless device. Further, the antenna integrated harness yields an effect such that (i) an antenna which is used as, for example, an in-car antenna or an antenna for another small device needs to occupy only a small space and (ii) an antenna element can be provided in a narrow space even if the narrow space is in a vicinity of a conductor.
A first embodiment of an antenna integrated harness in accordance with the present invention is described below with reference to
The antenna integrated harness 1a of the present embodiment includes a wire harness 10 formed by bundling a plurality of electric cables 11 and an antenna 20 having an antenna element 215 (see
Note that for convenience of explanation, in
(Wire Harness)
The wire harness 10 has the plurality of electric cables 11 and a tape member 16 with which the plurality of electric cables 11 are bundled, and a shield material 17 (see
The plurality of electric cables 11 have respective conductor parts and respective insulating parts which cover the conductor parts so as to cause the conductor parts to be insulated from each other.
The tape member 16 is not particularly limited in other conditions such as a material and a thickness provided that the tape member 16 allows the plurality of electric cables 11 to be bundled. A material may be selected which allows the wire harness 10 to be desirably efficient as a wire harness. For example, it is preferable to select a material which is excellent in wearability, heat resistance, adhesiveness, and the like.
Further, it is preferable that the tape member 16 be made of an insulating material. This is because, even in a case where a cover of the plurality of electric cables 11 is damaged, it is possible to maintain a state in which the respective conductor parts of the plurality of electric cables 11 and the antenna 20 are insulated from each other, and thus the plurality of electric cables 11 whose cover has been damaged does not adversely affect an antenna performance.
Note that the present embodiment uses a tape member as means for bundling the plurality of electric cables 11. However, the present invention is not limited to this, and it is possible to use a conventionally well-known material for bundling electric cables.
An outer surface of the wire harness 10 formed by bundling the plurality of electric cables 11 with the tape member 16 is covered with the shield material 17.
The shield material 17 serves as a shield that protects a group of the plurality of electric cables 11 thus bundled, and is made of an electrically conductive material. The shield material 17 allows blocking of a noise from the group of the plurality of electric cables 11, so that an influence of the noise on the antenna 20 which is provided on the exterior side of the shield material 17 can be suppressed. Note that the shield material 17 does not need to cover all the outer surface of the wire harness 10 and may merely cover (i) a region in which the antenna 20 is provided and (ii) a surrounding area of the region.
Note that neither the tape material 16 nor the shield material 17 needs to have a width which is equal to a total length of the wire harness 10 and tapes each having a shorter width than the total length of the wire harness 10 may be attached by winding to the wire harness 10 while partially overlapping with each other.
The wire harness 10 shown in
The present embodiment discusses an arrangement in which the antenna 20 is provided to one (1) wire harness 10. However, the present invention is not limited to this, and the antenna 20 may be provided on a surface formed by bundling wire harnesses.
(Antenna)
The antenna 20 is provided on, while conforming to, a surface of the wire harness 10 (see
The surface (also referred to as a side surface) of the wire harness 10 used in the present embodiment, i.e., the surface of the shield material 17 is a curved surface. Therefore, the antenna 20 which covers a part of that surface is also curved as shown in
The antenna 20 has a dielectric section 40 and the antenna element 215 (see
The dielectric section 40, which is made of a dielectric material, is provided so as to cause the shield material 17 and the antenna element 215 to be insulated from each other. The dielectric section 40 causes the shield material 17 and the antenna element 215 to be spaced at a predetermined distance. Specifically, it is only necessary that the shield material 17 serving as an electrically conductive material and the antenna element 215 be spaced at a distance of at least 2 mm (described later).
The dielectric section 40 is not particularly limited in structure provided that the dielectric section 40 serves as a spacer for retaining the predetermined distance at which the shield material 17 and the antenna element 215 are spaced. For example, the dielectric section 40 may be a two-dimensional dielectric layer which covers an entire surface of the antenna element 215, or may cover a part of the antenna element 215. Alternatively, the dielectric section 40 may be provided with a through hole or a recess, or may be constituted by a plurality of protrusions which are provided at regular intervals and are identical in height.
It is only necessary that the antenna 20 wound on the top surface of the shield material 17 of the wire harness 10 be arranged such that the winding of the antenna 20 does not cause both end parts of the antenna element 215 to overlap with each other. For example, in a case where the wire harness has a perimeter (circumference) of 120 mm, it is only necessary that the antenna element 215 of the antenna 20 wound on the wire harness 10 have a length, along the perimeter of the wire harness 10, of less than 120 mm.
Further, the antenna element 215 thus curved preferably has a curvature radius R of 5 mm or more. The antenna element 215 which is provided on, while conforming to, a curved surface having a curvature radius R of 5 mm or more can maintain its excellent antenna characteristic.
It is not particularly limited how to provide the antenna 20 to the wire harness 10 (shield material 17). For example, the antenna 20 may be adhered to the wire harness 10 by use of an adhesive, or may be fixed to the wire harness 10 by use of a fixing claw.
Note that, in a case where an insulating material having a thickness of at least 2 mm is further provided on the exterior of the shield material 17 of the wire harness 10, the antenna 20 may be arranged to have no dielectric section 40 but have the antenna element 215 provided on a surface of the insulating material.
The antenna element 215 of the antenna 20 is specifically described below with reference to
The antenna element 215, which is provided on, for example, a base material such as a thin resin, can be made of a conductor wire or a conductor film, or a printed wire.
The antenna element 215 has an electrically conductive path continuing from its one end part to the other end part, and the antenna element 215 is a single line. In view of the fact that the antenna element 215 has the electrically conductive path thus continuing from its one end part to the other end part, it can be said that the antenna element 215 is provided in a loop manner. With the antenna element 215 provided in a loop manner, it is possible to improve a gain of the antenna.
According to the antenna element 215, a part of the antenna element 215 which part extends from one end part by a predetermined length (i.e., a part corresponding to a wind section 211 which will be described later) and a part of the antenna element 215 which part extends from the other end part by a predetermined length (i.e., a part corresponding to the wind section 211) serve as a first root section 225 and a second root section 226, respectively. In the antenna element 215, a part of the antenna element 215 which part is other than these two root sections 225 and 226 serves as an intermediate section. That is, the intermediate section is a junction between the first root section 225 and the second root section 226.
A part of the intermediate section constitutes an antenna section 212 having a meander shape (meander line shape, meander-shaped part), and some part of the remainder of the intermediate section constitutes a first wider width part 213 and a second wider width part 214.
Meanwhile, the aforementioned two root sections 225 and 226 constitute the wind section 211. The first wider width part 213 and the second wider width part 214 share a common area with each other.
In summary, the electrically conductive path runs from its one end part of the antenna element 215 to the other end part in such a manner that the electrically conductive path begins with the first root section 225 and follows with the first wider width part 213, the second wider width part 214, the antenna section 212, and the second root section 226 in this order, and the second root section 226 comes back to a position near the first root section 225.
According to the first root section 225, the electrically conductive path continuing from its one end part to the other end part is drawn out in a leftward direction (i.e., a negative direction of the X axis) of the sheet on which
More specifically, both of the directions in which the respective first and second root sections 225 and 226 extend are opposite to each other (are rotated by 180 degrees) so as to surround a feed section 222.
As such, in either of the following cases: transmission or reception of a radio wave on a low frequency band side or transmission or reception of a radio wave on a high frequency band side, it is possible to obtain high radiant gains with respect to the respective radio waves.
Further, the direction in which the first root section 225 is drawn out is a direction in which the feed line 221 extends from the feed section 222, which will be described later, to a power-source side, i.e., the leftward direction (i.e., the negative direction of the X axis) of the sheet on which
Further, a direction in which the second root section 226 extends from the other end of the antenna element 215 is changed from a downward direction (i.e., a negative direction of the Z axis) of the sheet on which
As such, according to the wind section 211, both of the directions in which the respective first and second root sections 225 and 226 extend are rotated by 90 degrees so as to surround the feed section 222.
The part of the intermediate section of the antenna element 215 has a meander shape made up of at least one return pattern, more preferably two or more return patterns, in the antenna section 212. A return direction (i.e., the Z axis direction) of the return pattern in the meander shape is perpendicular to the direction (i.e., the positive direction of the X axis) in which the second root section 226 of the antenna element 215 is drawn out in the wind section 211, i.e. the direction in which the second bending part 226o2 (tail end linear part) extends.
According to the wind section 211, for the root sections 225 and 226, the aforementioned feed section 222 is provided. The root sections 225 and 226 are fed power by the feed line 221 which is connected to the feed section 222. Specifically, an outer electric conductor of a coaxial cable serving as the feed line 221 feeds power to the first root section 225, whereas an inner electric conductor of the coaxial cable feeds power to the second root section 226. There is provided, above the first wider width part 213b, a sheathed part of the coaxial cable. The sheathed part (i) is sheathed in an insulating jacket (i.e., a part where the outer electric conductor is not exposed) and (ii) is adjacent to an exposed part where the outer electric conductor is exposed.
The power is fed in the feed section 222 via the feed line 221 as follows. Specifically, in the feed section 222, (i) a signal, having a frequency which falls within a predetermined frequency band, is applied to the second root section 226 via the inner electric conductor of the coaxial cable, and (ii) an earth electric potential is applied to the first root section 225 via the outer electric conductor of the coaxial cable.
Further, the first wider width part 213, which lies below the feed line 221 and overlaps the feed line 221, has a line width (the length in the X axis direction) wider than a line width of a part that constitutes the wind section 211 and the antenna section 212 of the antenna element 215. This allows the feed section 222 to realize an impedance matching between the antenna element 215 and the feed line 221.
As is the case with the first wider width part 213, a line width of the second wider width part 214 is wider than the line width of the part that constitutes the wind section 211 and the antenna section 212 of the antenna element 215.
Unlike the case of
The feed line 221, which is connected to the feed section 222 of the antenna element 215, is provided, together with the plurality of electric cables 11, in the wire harness 10 while being bundled together with the plurality of electric cables 11 of the wire harness 10 in a vicinity of the feed section 222 (see
The antenna 20 (antenna element 215) has, for example, the following size: a length in a crosswise direction (i.e., X axis direction) of the sheet on which
Further, in the meander shape of the antenna section 212, there is provided a short-circuit member 231. The short-circuit member 231 may not only be provided as an independent member but also be formed integrally with the antenna element by use of a single material of which for example, the antenna element forming an electrically conductive path is made. The following description discusses the role of the short-circuit member 231 with reference to
Role of the Short-Circuit Member 231
As illustrated in
The short-circuit member 331 short-circuits for example two or more different points (a plurality of points) in the meandered antenna element 315. According to an example shown in
Note that, although
As described above, according to the antenna 301, the short-circuit member 331 is provided to the meandered antenna element 315 so as to short-circuit a plurality of different points, to thereby increase the number of electrically conductive paths having different lengths. This makes it possible to increase the number of resonance frequencies (resonance points) of the antenna 301, and thus possible to improve the VSWR characteristics of the antenna 301 in a usable band.
It should be noted here that, when an antenna is mounted on a conductor member, the antenna may deteriorate in VSWR characteristics (increase in VSWR value) in a usable band due to an effect of the conductor member. The usable band is for example 470 MHz to 770 MHz in a case of an antenna for terrestrial digital broadcasting in Japan, 470 MHz to 860 MHz in a case of an antenna for terrestrial digital broadcasting in North America, and 470 MHz to 890 MHz in a case of an antenna for terrestrial digital broadcasting in Europe.
In such a case, as described with reference to the antenna 301 shown in
According to the antenna 20 shown in
Where to provide the short-circuit member 231 is determined so that, under a condition where the antenna element 215 is provided on a metal plate via a dielectric material, a VSWR value in each frequency in the usable band becomes less than a VSWR value obtained in a case where no short-circuit member 231 is provided. It is more preferable that where to provide the short-circuit member 231 be determined so that, under a condition where the antenna element 215 is provided on a metal plate via a dielectric material, the VSWR value in each frequency in the usable band becomes not more than 3.5.
More specifically, the short-circuit member 231 is temporarily placed on the antenna element 215 which is provided via a dielectric material on a dummy metal plate, and then the short-circuit member 231 is moved while the VSWR value in the usable band is being monitored. If a position is found in which the VSWR value in each frequency in the usable band is less than the VSWR value obtained in the case where no short-circuit member is provided, then the short-circuit member 231 is fixed to that position. On the other hand, if no position is found in which the VSWR value in each frequency in the usable band is less than the VSWR value obtained in the case where no short-circuit member is provided, then the short-circuit member 231 is replaced with another short-circuit member 231 having a different shape or a different size and then the above trial is repeated.
The short-circuit member 231 is the one that causes a short circuit between predetermined points in the antenna element 215, and can be made for example from a conductive material such as metal. The short-circuit member 231 for example makes direct contact with the antenna element 215 to thereby cause a short circuit in the antenna element 215.
The following description discusses the results of experiments for examining how the presence of the short-circuit member 231 is related to VSWR characteristics.
Effect of Presence of Short-Circuit Member
In this experiment, an antenna device 401 (antenna element) was mounted via a dielectric layer 402 on a metal plate 403 which is 350 mm×250 mm in size and which serves as a conductor member (see
The antenna 20 shown in
As is clear from the experimental results shown in
In contrast, it is clear that the antenna 501 to which no short-circuit member is provided can prevent the VSWR from being greater than 3.5 in a frequency band of 650 MHz to 750 MHz.
Meanwhile, the antenna 501 can prevent the VSWR from being greater than 3.5 in a frequency band of approximately 650 MHz to 750 MHz, thus enabling excellent transmission and reception in such a frequency band. This can be considered as the effect achieved by the arrangement of the antenna 501 in which the antenna element 215 having a meander-shaped electrically conductive path is provided.
In the case of the antenna 501, excellent VSWR characteristics were achieved in the frequency band of approximately 650 MHz to 750 MHz. This result is merely an example. That is, by design changes to the meander shape, frequency band values and ranges that satisfy the VSWR of not greater than 3.5 can be changed in various ways. Therefore, depending upon a usable frequency band, the short-circuit member may be eliminated.
Effect of Thickness of Dielectric Material
The inventors have found that, by providing the dielectric layer 402 between the antenna device 401 and the metal plate 403 serving as a conductor member, it is possible to achieve an antenna device having a practical VSWR characteristic even when a distance between the antenna device 401 and the conductor member (metal plate 403) is reduced to approximately several millimeters (see
Further, the thickness d was changed to the following four thicknesses: d=Infinite (∞), d=5 mm, d=2 mm, and d=0 mm. Note that d=Infinite means that the distance between the antenna 20 and the metal plate 403 is infinite, i.e., no metal plate 403 is present. Further, d=0 mm means that the antenna 20 is mounted so as to be in contact with the metal plate 403 via an insulating member that is as thin as possible, such as an insulating film. That is, d=0 mm means that the antenna 20 and the metal plate 403 are close to each other as much as possible while a conductor part of the antenna 20 and the metal plate 403 are not in direct contact with each other.
It is clear from
When d=Infinite, that is, when the antenna 20 is not mounted on the metal plate 403, the antenna 20 is not affected by the metal plate 403. In other words, when the distance between the antenna 20 and the metal plate 403 is gradually reduced from infinite, the antenna 20 should become affected by the metal plate 403 more strongly as it approaches the metal plate 403.
That is, the results in
Note that
Therefore, according to the characteristic shown in
It is clear from
The antenna 20a has the following size: a length in a crosswise direction of a sheet on which
In a wind section 211a, a feed section 222a is provided in two root sections 225a and 226a of an antenna element 215a. Each of the two root sections 225a and 226a receives power via a feed line 221a connected with the feed section 222a.
The first root section 225a has a first linear part 225a1 and a first bending part 225a2 (tail end linear part), which correspond to the first linear part 225o1 and the first bending part 225o2 of the first root section 225 shown in
The feed line 221a extends in the negative direction of the Z axis in the sheet on which
Accordingly, a direction in which each of the two root sections 225a and 226a of the antenna element 215a is drawn out is perpendicular to the direction in which the feed line 221 extends.
Further, a line width (the length in the X axis direction) of a portion of a first wider width part 213a, which portion lies below the feed line 221a and overlaps the feed line 221a, is wider than a line width of a part that constitutes the wind section 211a and the antenna section 212a of the antenna element 215a.
The feed line 221a may extend in the negative direction of the X axis from the feed section 222a, which direction is different from that shown in
As in the case of the second wider width part 214 (described earlier), a line width of a second wider width part 214a is wider than a line width of the part that constitutes the wind section 211a and the antenna section 212a of the antenna element 215a.
Further, a short-circuit member 231a and a short-circuit member 232a are provided in a meander shape of the antenna section 212a. The roles of the short-circuit members 231a and 232a are the same as those of the short-circuit member 231.
Next, the following description discusses a difference in VSWR characteristic, which difference occurs depending on the presence or absence of the short-circuit members 231a and 232a.
Effect of Presence of Short-Circuit Member of Modified Example [1]
In the same manner as the foregoing experiment, the inventors mounted an antenna device 401 (antenna element) via a dielectric layer 402 on a metal plate 403 which is 350 mm×250 mm in size (see
The antenna 20a shown in
As is clear from the graph indicated by the “WITHOUT SECOND SHORT-CIRCUIT MEMBER” in
Further, it is clear from the graph indicated by the “WITH SHORT-CIRCUIT MEMBERS” that it is possible to prevent the VSWR from being greater than 3.5 also in a high-frequency band, out of the terrestrial digital television band (470 MHz to 770 MHz), by further providing the short-circuit member 232a to thereby cause a short circuit.
Note, however, that, as is clear from the graph indicated by “WITHOUT SHORT-CIRCUIT MEMBERS”, the antenna 503 prevents the VSWR from being greater than 3.5 in the frequency band of approximately 550 MHz to 620 MHz and the frequency band of approximately 680 MHz to 770 MHz (described earlier), thus enabling excellent transmission and reception in such frequency bands. This can be considered as the effect achieved by the arrangement of the antenna 503 in which the antenna element 215a having a meander-shaped electrically conductive path is provided. Therefore, depending upon a usable frequency band, the number of short-circuit members can be changed to any number including 0 (zero).
Effect of Thickness of Dielectric Material of Modified Example [1]
Further, the thickness d was changed to the following four thicknesses: d=Infinite (∞), d=5 mm, d=2 mm, and d=0 mm.
It is clear from
Further, it is clear from
These results show that, by causing the distance between the antenna 20a and the metal plate 403 to be equal to or larger than 2 mm, it is possible to prevent the VSWR from being greater than 3.5 in the band of 420 MHz to 870 MHz.
Note here that
Note that, also when d=0 mm, the VSWR is prevented from being greater than 3.5 in, for example, a frequency band in the vicinity of 450 MHz, a frequency band of approximately 520 MHz to 690 MHz, and a frequency band of approximately 750 MHz to 830 MHz, thus enabling excellent transmission and reception in such frequency bands. Therefore, in a case where a usable frequency band may be limited to a specific frequency, the antenna 20a of the present invention in which the antenna element 215 having a meander shape is provided can be placed as close as to a conductor while being insulated from a surface of the conductor.
It is clear from
The following description discusses a further modified example of the antenna mounted on the antenna integrated harness of the present embodiment.
The antenna 20b of
As in the case of the antenna 20a of the modified example [1] shown in
(Exterior Member)
As described at the beginning of the present embodiment, the antenna 20 is provided in the outermost layer (see
The exterior member 30 not only protects the wire harness 10 and the antenna 20 from an external shock but also prevents a conductor from adversely approaching the antenna 20. Specifically, the exterior member 30 can be made of a plastic material or the like.
In order to cover the wire harness 10 and the antenna 20, the exterior member 30 may be provided by, for example, providing a cleavage part along a longer-side direction of an exterior member made of a plastic material or the like, and cleaving the exterior member 30 at the cleavage part after the mounting of the antenna 20.
Further, the exterior member 30 covers an an entire circumference of the wire harness 10 and the antenna 20 in
As described earlier, the antenna integrated harness 1a includes the antenna 20 for use in a wireless device, the antenna 20 having the antenna element 215 which is two-dimensional planar (plate-like) and is provided on, while conforming to, the surface (may also be referred to as the side surface) of the wire harness 10, and the feed line 221 which is connected with the antenna element 215 is bundled with the plurality of electric cables 11 in the vicinity of the feed section 222. This allows an antenna element to transmit and receive radio waves on a surface of a wire harness.
This makes it possible to provide the antenna element 215 to a wire harness which is provided in a vicinity of a wireless device. According to this, a length of an antenna wire for use in connection between the antenna 20 and a wireless device can be shorter than that of a conventional antenna wire.
Further, given that the antenna element 215 is two-dimensional planar (plate-like) along the side surface of the wire harness 10, only a small space is necessary in which the antenna element 215 is to be provided. For example, in a case where the antenna element is a conductor having a thickness of 1 mm (described earlier), the wire harness merely becomes larger in diameter by approximately 2 mm. Even if the dielectric section 40 having a thickness of 2 mm is provided between the antenna element and the wire harness, the wire harness merely becomes larger in diameter by approximately 6 mm. This allows the antenna 20 to be provided also in a narrow space in which an antenna having a conventional arrangement cannot be provided.
Further, according to the arrangement, the feed line 221, which is bundled with the plurality of electric cables 11 in the vicinity of the feed section 222, constitutes the wire harness 10. According to this, unlike a conventional arrangement, an arrangement in which the wire harness 10 is used as, for example, a wire harness for an automobile eliminates the need to cause a feed line to be through a through hole provided to a body. Therefore, such an arrangement makes it easier to provide a feed line as compared to the conventional arrangement.
Further, in a case where antennas for terrestrial digital broadcasting are put into practical use, the antennas will be mounted on various receivers such as a mobile phone, a personal computer, a car navigation system, and an in-car television receiver each serving as a receiving terminal of the terrestrial digital broadcasting. Note that, in a case where an antenna is mounted on a conductor member made of a metal plate or the like, the antenna is inevitably affected by the conductor member. That is, unlike a case where an antenna alone is provided in a vacuum free space, in a case where an antenna is mounted on a conductor member, it is necessary to design an antenna integrated harness in view of an influence of the conductor member on the antenna. Therefore, according to the present embodiment, an antenna is mounted on a conductor member in view of an influence thereon of the conductor member. In order to realize such an arrangement, a short-circuit member (short-circuit section) is used to determine a position and a portion in which the short-circuit member is to be provided, to thereby increase the number of resonance points of an antenna element and to reduce a VSWR value. According to this, even in a case where an antenna (antenna integrated harness) is mounted on a conductor member, it is possible to expand a usable band.
Note that the present embodiment discusses an arrangement in which the antenna 20 is provided to one (1) wire harness 10. However, the present invention is not limited to this, and the antenna 20 may be provided on a surface formed by bundling wire harnesses.
According to the present embodiment, a cross section of the wire harness 10 has a circular shape (see
Further, the antenna 20 of the present embodiment may be provided with not only the antenna element 215 but also a tuner section 4 (transmitting and receiving circuit) (see
With such an arrangement in which the tuner section 4 and the antenna element 215 are provided side by side on a single surface, it is possible to shorten a conduction route for use in connection between the antenna element 215 and the tuner section 4. This makes it possible to reduce a loss caused by the conduction route and to form the conduction route to be thin.
It is possible to take, as an example, a case where a part of a receiving system and a transmitting system of an in-car device, and the antenna element 215 are provided side by side on a single surface. Specifically, it is assumed that the receiving system is mainly a system for receiving terrestrial digital broadcasting and that the transmitting system is mainly ITS (Intelligent Transport Systems) which is a communication system such as ETC. Note that besides these systems, a receiving/transmitting system of an in-car device may also be a system for use in WiMax communication.
The receiving system includes an antenna, a receiving circuit, a demodulator circuit, an AV decoder, and a car navigation device.
According to the receiving system, a signal (received signal) received by the receiving circuit which is connected with the antenna 20 via the feed line 221 is transmitted to the demodulator circuit at a subsequent stage.
The demodulator circuit demodulates the signal thus received and transmits the demodulated signal to the AV decoder at a subsequent stage.
The AV decoder decodes the demodulated signal and transmits the decoded signal to the car navigation device at a subsequent stage.
The car navigation device displays an image in accordance with the signal decoded by the AV decoder.
Meanwhile, the transmitting system includes an antenna, a transmitting circuit, a modulation circuit, a control section, and a car navigation device.
According to the transmitting system, in accordance with a signal transmitted from the car navigation device, the control section supplies a control signal to the modulation circuit.
The modulation circuit modulates the control signal and transmits the modulated signal to the transmitting circuit at a subsequent stage.
The transmitting circuit transmits the control signal from the antenna via a feed line.
Note here that provision of a part of a receiving system and/or a transmitting system and the antenna element 215 side by side on a single surface means, in the case of the receiving system, employment of an embodiment in which the receiving circuit or the receiving circuit and the demodulator circuit, and the antenna element 215 are provided side by side on a single surface. Note also that provision of a part of a receiving system and/or a transmitting system and the antenna element 215 side by side on a single surface means, in the case of the transmitting system, employment of an embodiment in which the transmitting circuit or the transmitting circuit and the modulation circuit, and the antenna element 215 are provided side by side on a single surface.
In a case where a part of such a system(s) and the antenna element 215 are provided side by side on a top surface (a single surface) of a base material of a dielectric material, it is possible to yield an effect of making a wireless device smaller or thinner, or an effect such that, since a transmitting and receiving circuit can be provided so as to be adjacent to an antenna, it is unnecessary to consider an impedance of a transmission path from the antenna to the transmitting and receiving circuit.
Note that an antenna which is surrounded by a conductor cannot carry out transmission/reception and that an antenna which is not surrounded by a conductor but along which a conductor plate is provided between the antenna and an outside deteriorates in transmission/reception characteristic. Therefore, in a case where the antenna 20 is arranged to be integrated with a wireless device, it is preferable that the antenna 20 be provided on a surface of a conductor plate located on the outermost side of the wireless device, or on a surface of a dielectric plate such as a resin covering the conductor plate.
The present embodiment has discussed an arrangement in which the antenna 20 is provided on the surface of the wire harness 10 (shield material 17). Alternatively, the antenna 20 may be provided on an inner surface of the exterior member 30. Further, according to
The present embodiment has discussed an arrangement in which one (1) antenna 20 is attached to a surface of the tape member 16. However, the present invention is not limited to this, and a plurality of antennas 20 may be attached to the surface of the tape member 16. In this case, two of the plurality of antennas can be used to carry out reception in a diversity mode. That is, since it is possible to preferentially use a received signal of an antenna 20 that carries out reception in good condition, a wireless device can carry out reception with higher sensitivity. Note that, in a case where reception is carried out in the diversity mode, it is desirable that antennas or antenna integrated harnesses be provided at some distance therebetween in view of reception sensitivity.
Next, a second embodiment of an antenna integrated harness in accordance with the present invention is described below.
According to Embodiment 1, the antenna 20 is provided to the wire harness 10 (see
The following description of the present embodiment takes, as an example of the member, a protector 50 for regulating a path of a wire harness and protecting against an external damage to the wire harness.
The protector 50 can be made of, for example, a resin. As shown in
In a case where the protector 50 shown in
According to the present embodiment, the antenna 20 is provided on a surface of the protector 50 thus arranged. Since an arrangement of an antenna element 215 of the antenna 20 has been specifically discussed in Embodiment 1, a description thereof is omitted here.
A feed line 221 connected with a feed section 222 of the antenna element 215 is drawn into the protector 50 via a through hole 52 of the protector 50, the through hole 52 being provided in a vicinity of the feed section 222. Then, the feed line 221 is drawn out from the protector 50 via one of the aperture regions 51 of the protector 50, and constitutes the wire harness 10 by being bundled with the plurality of wires 11 belonging to a corresponding one of the two groups and having been drawn out from the protector 50 via the one of the aperture regions 51.
According to
The protector 50 may be provided with guide means for guiding the feed line 221 to each of the aperture regions 51. The guide means is, for example, a guide groove. Note that the through hole 52 also serves as an example of the guide means.
The antenna 20 can be provided on the surface of the protector 50 by the method described in Embodiment 1. Further, the antenna 20 may also be embedded in the protector 50.
Note that Embodiment 1 has described that the antenna element 215 and the plurality of electric cables 11 (conductor member) need to be separated from each other by a given distance. Also for the antenna integrated harness 1b of the present embodiment, this point needs to be considered. Therefore, in a case where a part of the protector 50 in which part the antenna 20 is provided is made of a dielectric material and a thickness of the part is set to 2 mm or more, the antenna element 215 can also be formed directly on the surface of the protector 50.
Note that a position in which the antenna 20 is provided is not limited to a position shown in
According to the present embodiment, the antenna 20 is provided to the protector 50 (see
The grommet 60 (see
According to the present invention, it is also possible to fix the antenna 20 on a surface of the grommet 60 of
Note that the present invention also encompasses a member which is attached to a harness and provided with an antenna that is provided on, while conforming to, a surface of the member or is embedded in the member. Namely, the present invention also encompasses a member which is attached to a harness and can be connected with a wire harness formed by bundling a plurality of electric cables, the member including: an antenna element which is two-dimensional planar (plate-like) and is provided on, while conforming to, a surface of the member; and a feed line which is connected with the antenna element and which can be bundled with the plurality of electric cables when the member is connected with the wire harness.
The feed line 221 can be arranged as a part of the wire harness 10 by being drawn into the connector via a hole 71 provided to the connector 70.
Note that the feed line 221 may also be arranged as one of connection terminal groups 72 by being drawn into the connector via the hole 71, the connection terminal groups 72 being provided on a side surface of the connector.
Further, the antenna element 215 may be embedded in the connector 70.
As described earlier, each of the antenna integrated harnesses 1b, 1b′, and 1b″ of the present embodiment includes the antenna 20 which is used for a wireless device and is provided with the antenna element 215 that is two-dimensional planar and is fixed on the surface of the member for being connected with the wire harness 10, and the feed line 221 which is connected with the antenna element 215 is bundled with the plurality of electric cables 11 of the wire harness 10 in the vicinity of the feed section 222. This allows the antenna element to transmit and receive radio waves on the surface of the member.
Therefore, the antenna element 215 can be provided on a surface of a member which is connected with the wire harness 10 and is located in a vicinity of a wireless device. According to this, an antenna wire for use in connection between the antenna 20 and the wireless device can be remarkably shorter in length than a conventional antenna wire.
Further, given that the antenna element 215 is two-dimensional planar along the surface of the member, only a small space is necessary in which the antenna element 215 is to be provided. For example, in a case where the antenna element is a conductor having a thickness of 1 mm (described earlier), even if the dielectric section 40 having a thickness of 2 mm is provided between the antenna element and the member, the member merely becomes slightly larger. This allows the antenna 20 to be provided also in a narrow space in which an antenna having a conventional arrangement cannot be provided.
Next, a third embodiment of an antenna integrated harness in accordance with the present invention is described below.
According to Embodiment 1, the antenna 20 is provided to the wire harness 10 (see
The fuse box 80 is a device for, for example, distributing electricity to an automobile, and is provided in, for example, an engine room. The fuse box 80 is provided with an external connection terminal 81. The external connection terminal 81 is electrically connected with an electric cable of the wire harness 10 via a connector 90 (see
The antenna 20 has an antenna element 215 which is fixed on, while conforming to, a surface of the fuse box 80.
A feed line 221 connected with a feed section 222 of the antenna element 215 is drawn into the fuse box 80 via a through hole 82 of the fuse box 80, the through hole 82 being provided in a vicinity of the feed section 222.
An antenna terminal 83 connected with the feed line 221 is provided in a vicinity of the external connection terminal 81 of the fuse box 80.
For example, while providing the external connection terminal 81 and the antenna terminal 83 in proximity to each other, it is also possible to provide the connector 90 with a terminal corresponding to the antenna terminal 83. According to this, an electric cable connected with the terminal can be arranged as the wire harness 10 by being bundled with other electric cables.
Note that the antenna 20 does not need to be fixed on, while conforming to, the surface of the fuse box 80 but may be embedded in a case of the fuse box 80.
As described earlier, the antenna integrated harness 1c of the present embodiment includes the antenna 20 which is provided with the antenna element 215 that is two-dimensional planar and is fixed on the surface of the fuse box, and the fuse box 80 has, on its side surface, the external connection terminal (antenna terminal 83) which is electrically connected with the feed line 221 that is connected with the antenna element 215. This allows the antenna element 215 to transmit and receive radio waves on the surface of the fuse box.
Note that an external electric cable which is electrically connected with the antenna terminal 83 via another terminal can be arranged as the wire harness 10 by being bundled with other electric cables.
Further, given that the antenna element 215 is two-dimensional planar along the surface of the member, only a small space is necessary in which the antenna element 215 is to be provided. This allows the antenna 20 to be provided also in a narrow space in which an antenna having a conventional arrangement cannot be provided.
The present invention is not limited to the description of the embodiments above, but may be altered by a skilled person within the scope of the claims. An embodiment based on a proper combination of technical means disclosed in different embodiments is encompassed in the technical scope of the present invention.
[Conclusion]
As described earlier, a first antenna integrated harness in accordance with the present invention includes: a wire harness formed by bundling a plurality of electric cables; an antenna element which is plate-like and is provided on, while conforming to, a surface of the wire harness; and a feed line connected with the antenna element and bundled with the plurality of electric cables.
According to the arrangement, the first antenna integrated harness in accordance with the present invention includes an antenna element which is plate-like (two-dimensional planar) and is provided on, while conforming to, a surface of a wire harness (i.e., a surface along a length direction of the wire harness). Namely, the arrangement allows the antenna element to transmit and receive radio waves on the surface of the wire harness.
Further, given that the antenna element is plate-like along the surface of the wire harness, only a small space is necessary in which the antenna element is to be provided. For example, in a case where the antenna element is a conductor having a thickness of 1 mm (described later), the wire harness merely becomes larger in diameter by approximately 2 mm. This allows an antenna of the present invention to be provided also in a narrow space in which an antenna having a conventional arrangement cannot be provided.
According to the arrangement, the feed line is bundled with the plurality of electric cables. According to this, in a case where the first antenna integrated harness in accordance with the present invention is used as, for example, a wire harness for an automobile, it is possible to provide an antenna without the need of carrying out a conventional complicated step of mounting an antenna by providing a through hole for a connection between an outside and an inside of the automobile.
Note that “an antenna element which is plate-like and is provided on, while conforming to, a surface of a wire harness” encompasses not only (1) a state in which the antenna element is provided on the surface of the wire harness but also all the following states (described later): (2) a state in which the antenna element is not in direct contact with the surface of the wire harness, i.e., a state in which the antenna element is provided on an outer surface of a dielectric material which is provided on the surface of the wire harness, (3) a state in which the antenna element is provided on an inner surface of a dielectric material provided on, while conforming to, the surface of the wire harness, and (4) a state in which the antenna element is embedded in a dielectric material provided on, while conforming to, the surface of the wire harness.
Note that a “plate-like” plane is not limited to a two-dimensional plane but may be a plane which (i) is obtained by cutting off a part of a curved surface such as a cylindrical surface, a spherical surface, a paraboloid, or a hyperboloid and (ii) has a three-dimensional shape.
As described earlier, a second antenna integrated harness in accordance with the present invention includes: a wire harness formed by bundling a plurality of electric cables; a member which can be connected with the wire harness; an antenna element which is plate-like and is provided on, while conforming to, a surface of the member; and a feed line which is connected with the antenna element and which can be bundled with the plurality of electric cables when the member is connected with the wire harness.
According to the arrangement, the second antenna integrated harness in accordance with the present invention includes an antenna element which is plate-like (two-dimensional planar) and is provided on, while conforming to, a surface of a member which can be connected with the wire harness. Namely, the arrangement allows the antenna element to transmit and receive radio waves on the surface of the member.
Further, given that the antenna element is plate-like along the surface of the member, only a small space is necessary in which the antenna element is to be provided. For example, in a case where the antenna element is a conductor having a thickness of 1 mm (described later), a size of the member is substantially unchanged. This allows an antenna of the present invention to be provided also in a narrow space in which an antenna having a conventional arrangement cannot be provided.
Further, since the antenna element is fixed to the member, it is unnecessary to carry out a conventional complicated step of mounting an antenna by providing a through hole for a connection between an outside and an inside of the automobile.
Each of the first antenna integrated harness and the second antenna integrated harness in accordance with the present invention is also preferably arranged such that: the antenna element has an electrically conductive path continuing from one end part to the other end part, and causes the electrically conductive path to be loop-shaped by having a feed section provided in the one and the other end parts of the electrically conductive path; the antenna element has a first root section which includes the one end part of the electrically conductive path, a second root section which includes the other end part of the electrically conductive path, and an intermediate section which lies between the first root section and the second root section; the feed section is provided in the first root section and the second root section; the first root section and the second root section are arranged, in a first region that is part of a region where the electrically conductive path is formed, so as to surround the feed section; in the first region, tail end linear parts of the respective first and second root sections, which tail end linear parts are directly connected with the intermediate section, extend in respective opposite directions; at least one of the first and second root sections has a wider width part which is formed such that a portion that overlaps the feed line connected with the feed section is larger in width than other portions; and the intermediate section has a meander shape made up of at least one return pattern.
According to the arrangement, the antenna element which has an electrically conductive path continuing from one end part to the other end part causes the electrically conductive path to be loop-shaped by having a feed section provided in the one and the other end parts of the electrically conductive path. According to this, as in the case of a conventionally well-known loop antenna, each of the antenna integrated harnesses thus arranged makes it possible to obtain a high radiant gain.
Further, each of the first antenna integrated harness and the second antenna integrated harness in accordance with the present invention can be arranged such that the antenna element has a first root section which includes the one end part of the electrically conductive path, a second root section which includes the other end part of the electrically conductive path, and an intermediate section which lies between the first root section and the second root section; the feed section is provided in the first root section and the second root section; and the first root section and the second root section are arranged, in a first region that is part of a region where the electrically conductive path is formed, so as to surround the feed section. In addition, each of the first antenna integrated harness and the second antenna integrated harness in accordance with the present invention can be arranged such that in the first region, tail end linear parts of the respective first and second root sections, which tail end linear parts are directly connected with the intermediate section, extend in respective opposite directions; and at least one of the first and second root sections has a wider width part which is formed such that a portion that overlaps the feed line connected with the feed section is larger in width than other portions.
This allows the feed section to realize an impedance matching between the antenna element and the feed line, to thereby reduce a VSWR value of the antenna element. Namely, it is possible to improve a VSWR characteristic.
Further, since the intermediate section has a meander shape made up of at least two return patterns, even a loop-shaped electrically conductive path can be compactly provided. In addition, in either of the following cases: transmission or reception of a radio wave on a low frequency band side or transmission or reception of a radio wave on a high frequency band side, it is possible to improve non-directivity radiation characteristics with respect to the respective radio waves.
In view of the above, the antenna element having the arrangement makes it possible to improve a non-directivity radiation characteristic and to improve its VSWR characteristic while realizing its high radiant gain. Therefore, it is possible to expand a region in which the antenna element can be used.
Each of the first antenna integrated harness and the second antenna integrated harness in accordance with the present invention is preferably arranged to further include a dielectric section which is provided on the surface side of the antenna element.
According to the arrangement, for example, in a case where an antenna integrated harness includes a wire harness and an antenna element, and further includes a dielectric section provided on a surface of the antenna element which surface faces the wire harness, it is possible to realize a state in which the antenna element and the plurality of electric cables of the wire harness are insulated or substantially insulated from each other. This makes it possible to provide the antenna element in a vicinity of the plurality of electric cables of the wire harness. Even the antenna element thus provided can exhibit an excellent antenna characteristic without losing its characteristic.
However, each of the first antenna integrated harness and the second antenna integrated harness in accordance with the present invention may be arranged such that: the surface is made of a dielectric material; and the antenna element is provided on, while conforming to, a surface of the dielectric material.
According to the arrangement, for example, in a case where an antenna integrated harness includes a wire harness and an antenna element, and a surface of the wire harness is made of a dielectric material, it is possible to realize a state in which the antenna element and the plurality of electric cables of the wire harness are insulated or substantially insulated from each other. This makes it possible to provide the antenna element in a vicinity of the plurality of electric cables of the wire harness. Even the antenna element thus provided can exhibit an excellent antenna characteristic without losing its characteristic.
The first antenna integrated harness in accordance with the present invention may be arranged to further include: an exterior member which covers the antenna element and the surface of the wire harness, the antenna element being provided on a surface of the exterior member.
According to the arrangement, since the antenna element is provided to the exterior member, a conductor of the wire harness and the antenna element can be sufficiently spaced.
Each of the first antenna integrated harness and the second antenna integrated harness in accordance with the present invention is preferably arranged such that: the surface of the wire harness or the member is a curved surface; and the antenna element has a shape along the curved surface.
According to the arrangement, the antenna element can be provided on, while conforming to, the surface of the wire harness or the member which surface has a curved shape. Therefore, the antenna element whose structure is limited to a flat and plate-like structure cannot be provided on, while conforming to, such a surface. Even if such an antenna element is provided on, while conforming to, the surface, a wide space is necessary in which the antenna element is to be provided. However, according to the arrangement, the antenna element can be provided on, while conforming to, the curved surface. This makes it possible to provide an antenna even in a narrow space.
Each of the first antenna integrated harness and the second antenna integrated harness in accordance with the present invention is preferably arranged such that: the curved surface along which the antenna element has a shape has a curvature radius of 5 mm or more.
As described earlier, in a case where the antenna element can be provided on, while conforming to, the curved surface which has a curvature radius of 5 mm or more, each of the antenna integrated harnesses can maintain its excellent antenna characteristic.
Each of the first antenna integrated harness and the second antenna integrated harness in accordance with the present invention may be arranged such that: the antenna element is provided on a base material; and at least one of a transmitting circuit and a receiving circuit is provided on the base material.
According to the arrangement, it is possible to shorten a conduction route for use in connection between the antenna element and a transmitting and receiving circuit. This makes it possible to reduce a loss caused by the conduction route and to form the conduction route to be thin.
Note that a movable body on which an antenna integrated harness mentioned above is mounted is also included within the scope of the present invention.
The present invention is applicable to an antenna for receiving a broadcast wave. In particular, the present invention provides an antenna that is suitably provided in a place such as an automobile in which an antenna device is provided in a limited space and many conductor parts are provided around the antenna device.
Number | Date | Country | Kind |
---|---|---|---|
2010-259589 | Nov 2010 | JP | national |
This application is a Continuation of PCT International Application No. PCT/JP2011/076716 filed in Japan on Nov. 18, 2011, which claims the benefit of Patent Application No. 2010-259589 filed in Japan on Nov. 19, 2010, the entire contents of which are hereby incorporated by reference.
Number | Date | Country | |
---|---|---|---|
Parent | PCT/JP2011/076716 | Nov 2011 | US |
Child | 13896756 | US |