JP2004260570A - Diversity antenna, diversity antenna device, and method for manufacturing diversity antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diversity antenna securing a sufficient diversity effect without restricting an installation place significantly. <P>SOLUTION: Outer conductors 12b on forward end sides of a pair of coaxial cables 12 having central conductors 12d and outer conductors 12c provided in insulated states are turned up and then the forward end sides of the coaxial cables 12 are molded independently with soft insulating resin and the coaxial cables 12 closer to the root side than the molded part 16 are bundled by a bundling member 13. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a diversity antenna including a pair of elastic dipole antennas, a diversity antenna device, and a method for manufacturing a diversity antenna.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a diversity antenna having a pair of antennas for obtaining a so-called diversity effect has been known.
[0003]
The diversity antenna has an effect of improving the receiving sensitivity particularly when it is provided on a moving body such as a vehicle whose arrival direction of a radio wave is not determined.
[0004]
FIG. 4 is a cross-sectional view of a main part showing an example of a diversity antenna device mounted on a vehicle (for example, see Patent Document 1).
[0005]
In FIG. 4, 1 is an antenna main body, 2 is a U-shaped (upward) antenna holder in front view, 3 is a hard cylindrical cover made of a dielectric held at each end of the antenna holder 2, and 4 is each One end faces the inside of the cylindrical cover 3 and the other end is a coaxial cable connected to an antenna device body (not shown).
[0006]
A parasitic element or the like is provided in the cylindrical cover 3 so as to cover the coaxial cable 4, thereby forming a dipole antenna 5.
[0007]
It should be noted that a technique for forming the dipole antenna 5 using the coaxial cable 4 is also known in Patent Document 2 and the like in addition to the technique described above.
[0008]
FIG. 5 is an explanatory diagram showing another example of the diversity antenna device mounted on the vehicle.
[0009]
In FIG. 5, reference numeral 6 denotes an antenna device main body, 7 denotes a pair of linear wirings independently drawn from the antenna device main body 6, and 8 denotes a sheet-shaped antenna main body provided at the end of the linear wiring 7.
[0010]
The antenna body 8 of the diversity antenna device shown in FIG. 5 is, for example, one that is mounted as a transparent body with the entire sheet affixed to a position not obstructing the field of view of the upper right and left sides of the vehicle body windshield. It is known.
[0011]
[Patent Document 1]
Japanese Utility Model Application Laid-Open No. 61-146011 (page 4-7, FIG. 2)
[Patent Document 2]
JP-A-6-140826
[Problems to be solved by the invention]
By the way, in the diversity antenna device configured as described above, for example, the diversity antenna device shown in FIG. 5, since the coaxial cable 4 is covered with the hard cylindrical cover 3, the pair of dipole antennas 5 is hard. Since the dipole antenna 5 is held by the antenna holder 2, the interval between the dipole antennas is determined, so that not only the position of the vehicle body is easily restricted, but also There has been a problem that a diversity effect is hardly received depending on the installation location.
[0013]
Further, in the diversity antenna device shown in FIG. 5, since the linear wiring 7 having no strength is used, the installation position of the antenna main body 8 is set to the position inside the window glass room, inside the bumper, inside the air spoiler, or the like. And the size of the sheet is relatively large (for example, a transparent sheet of about 10 cm × 20 cm), which substantially restricts the installation position of the vehicle body. .
[0014]
Further, since each antenna body 8 is completely independent of the antenna device body 6, they are arranged at positions that are too far apart from each other, and there is a problem that a sufficient diversity effect cannot be obtained.
[0015]
An object of the present invention is to provide a diversity antenna, a diversity antenna device, and a method of manufacturing a diversity antenna that can hardly be restricted by an installation place and that can obtain a sufficient diversity effect in order to solve the above problem. .
[0016]
[Means for Solving the Problems]
In order to achieve the object, the diversity antenna of the present invention uses a pair of coaxial cables in which a center conductor and an outer conductor are provided in an insulated state, and folds the outer conductor on each end side of the pair of coaxial cables. In the above, the distal end side of each of the coaxial cables is independently molded with a soft insulating resin, and the coaxial cables on the base side of the molded portion are bound with a binding member.
[0017]
Further, the diversity antenna device of the present invention has a pair of coaxial cables each having a base end connected to the antenna device main body and having a center conductor and an outer conductor provided in an insulated state, and a pair of coaxial cables each having a distal end. A flexible insulating resin material in which the distal end side of each of the coaxial cables is independently molded in a state where the outer conductor is folded; an adhesive member provided in the flexible insulating resin material; and a base end side with respect to the flexible resin material. And a binding member for binding the coaxial cable so that the distal end side of the coaxial cable is a free end.
[0018]
Further, the diversity antenna device of the present invention is characterized in that a connector for power supply / control signal is connected to the antenna device main body.
[0019]
Further, in the method for manufacturing a diversity antenna according to the present invention, the outer conductors at the respective distal ends of a pair of coaxial cables provided with a center conductor and an outer conductor in an insulated state are cut off at a predetermined length, and the outer portions exposed by the cut are cut off. After the conductor is folded back to the root side and independently molded from a tip of the center conductor with a soft insulating resin so as to cover the entire outer conductor after the folding, a middle part of the coaxial cables is bound with a binding member. It is characterized by.
[0020]
Further, in the method of manufacturing a diversity antenna according to the present invention, the folded length of the outer conductor after cutting the outer skin and the length from the cut portion of the outer skin to the tip of the center conductor are each λ / 4. Features.
[0021]
Further, in the method of manufacturing a diversity antenna according to the present invention, when molding with the soft insulating resin, a material is injected from a base end side to a tip end side of the coaxial cable, and moves along the injection direction. In addition, a piece member for positioning the coaxial cable at the center of the mold is used.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the diversity antenna device of the present invention will be described with reference to the drawings.
[0023]
1A and 1B show a diversity antenna device of the present invention, FIG. 1A is a front view of the appearance of the diversity antenna device, FIG. 1B is a perspective view of the antenna body alone, and FIG. 1C is a plan view of the antenna body. FIG. 2 is an enlarged sectional view of an antenna body used in the diversity antenna device of the present invention, and FIG. 3 is an explanatory view of a process of manufacturing the antenna body used in the diversity antenna device of the present invention.
[0024]
In FIG. 1, a diversity antenna device 10 includes a housing-shaped antenna device main body 11, two coaxial cables 12 (for example, 50Ω) pulled out from the antenna device main body 11, and a tip end of each coaxial cable 12. A tying member 13 which is tied to a free end independent from the tying portion, an antenna body 14 provided at each end of the coaxial cable 12, and a battery (not shown) which is drawn out of the antenna device body 11 And a connection connector 15 that is connected to a power supply from a computer, a sound control device, and the like.
[0025]
The connection connector 15 may be, for example, an optional type in which only the power supply is performed and the connection with the acoustic control device is performed by the antenna device body 11 itself. It is also possible to facilitate the setting (combination) of the option of the in-vehicle device such as the combined use with the system.
[0026]
As shown in FIGS. 3A to 3D, the antenna body 14 cuts the outer sheath 12a of the coaxial cable 12 at a predetermined length (FIG. 3B), and exposes the outer conductor exposed by the cutting of the outer sheath 12a. After turning back 12b to the root side and fixing the middle part with the heat-shrinkable tube 17 (FIG. 3 (C)), the whole outer conductor 12b after turning back from the tip of the center conductor 12d integral with the inner jacket 12c is made independent. Covered with a mold portion 16 made of a soft insulating resin material.
[0027]
At this time, the outer conductor 12b is not folded back so as to turn up the entirety (see Patent Document 2), but is folded back substantially to the half side, and as shown in FIG. The cut length of the outer skin 12a before turning back is λ / 4, which is substantially the same length.
[0028]
For example, when the total length of the mold section 16 is 200 mm (± 5 mm), λ / 4 = 81 mm (± 2 mm).
[0029]
The mold section 16 has a substantially semicircular cross section, and the thickness corresponding to the radius is about 7 mm in consideration of the diameter of the coaxial cable 12 to be used. Further, a double-sided tape 18 for attaching the antenna body 14 to the vehicle body is provided on a plane portion of the mold portion 16.
[0030]
As a result, the antenna main body 14 has elasticity capable of being bent and deformed as a whole, and has a slightly thicker wire structure than the coaxial cable 12. Any position can be set.
[0031]
In addition, since the length of the free end of the coaxial cable 12 is predetermined by the binding member 13 in consideration of the characteristics and the like of the in-vehicle information device (300 mm ± 100 mm), even if the antenna main bodies 14 are arranged substantially in parallel, Even if they are arranged in a T shape or a substantially L shape, a good diversity effect can be ensured.
[0032]
Further, the folding direction of the outer conductor 12b is opposite to the plane portion of the mold portion 16, that is, the outer conductor 12b is folded toward the non-body attaching surface side. It is hard to be affected by such factors.
[0033]
In addition, as the soft insulating resin material forming the mold portion 16, a material considering heat resistance and flexibility is used (for example, a rubber-based resin).
[0034]
Also, when molding the molded portion 16, the piece member 19 having a hole having an inside diameter substantially the same as the maximum diameter of the coaxial cable 12 is moved to the base end side of the coaxial cable 12 while moving in the mold (not shown). When the soft resin material is injected into the mold, the coaxial cable 12 is moved over the coaxial cable 12 by the injection pressure while the coaxial cable 12 is positioned substantially at the center of the molded portion 16 after molding. Thus, the coaxial cable 12 and the molded portion 16 are positioned on substantially the same center line as a whole.
[0035]
【The invention's effect】
In the diversity antenna device of the present invention, the configuration as described above allows the installation location to be hardly restricted and a sufficient diversity effect to be obtained.
[Brief description of the drawings]
1A and 1B show a diversity antenna device of the present invention, in which FIG. 1A is a front view of the appearance of the diversity antenna device, FIG. 1B is a perspective view of the antenna main body alone, and FIG. 1C is a plan view of the antenna main body.
FIG. 2 is an enlarged sectional view of an antenna body used in the diversity antenna device of the present invention.
FIG. 3 is an explanatory diagram of a manufacturing process of an antenna main body used in the diversity antenna device of the present invention.
FIG. 4 is a sectional view of a main part showing an example of a conventional diversity antenna device mounted on a vehicle.
FIG. 5 is an explanatory diagram showing another example of a diversity antenna device mounted on a conventional vehicle.
[Explanation of symbols]
Reference Signs List 10 diversity antenna device, 11 antenna device main body, 12 coaxial cable, 13 binding member, 14 antenna main body, 15 connector, 16 mold portion, 18 double-sided tape.

Claims (6)

Using a pair of coaxial cables in which a central conductor and an outer conductor are provided in an insulated state, and bending the outer conductors at the respective distal ends of the pair of coaxial cables, and then independently controlling the distal ends of the coaxial cables independently. A diversity antenna formed by molding with an insulating resin and binding each coaxial cable closer to the base side than the molded portion with a binding member. A pair of coaxial cables, the base ends of which are connected to the antenna device main body and the center conductor and the outer conductor are provided in an insulated state, and the outer conductors at the distal ends of the pair of coaxial cables are folded. A flexible insulating resin material in which the distal end side of each coaxial cable is independently molded, an adhesive member provided in the flexible insulating resin material, and a distal end side of the coaxial cable positioned closer to a base end side than the soft resin material. A diversity antenna device, comprising: a binding member that binds the two so as to be a free end. The diversity antenna device according to claim 2, wherein a power / control signal connection connector is connected to the antenna device body. A pair of coaxial cables provided with a central conductor and an outer conductor in an insulated state are cut at predetermined lengths at outer ends of the coaxial cables, and the outer conductor exposed by the cut is turned back to the root side, and the end of the center conductor is cut off. A method of manufacturing a diversity antenna, comprising: independently molding a soft insulating resin so as to cover the whole of the folded outer conductor, and then bundling a middle part of the coaxial cables with a bundling member. 5. The diversity antenna according to claim 4, wherein a folded length of the outer conductor after the outer skin is cut and a length from the cut portion of the outer skin to the tip of the center conductor are each λ / 4. 6. Production method. When molding with the soft insulating resin, a piece member for injecting a material from the base end side to the tip end side of the coaxial cable and positioning the coaxial cable at the center of the mold while moving along the injection direction. The method for manufacturing a diversity antenna according to claim 4, wherein:

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