JP2005223546A - Antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna effective for the cut down of the number of components. <P>SOLUTION: A power feeding coaxial cable 20 is laid on the backside of a ground conductor board 11 only a core 21 of this cable is led out to the front side of the ground conductor board through a through-hole formed in the ground conductor board, and a part of the top end of the led-out portion is bent in parallel to an antenna element 12 so that the top end serves also as a feeding probe 25. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an antenna device, and more particularly to a small antenna device suitable for receiving not only terrestrial waves but also radio waves from artificial satellites.

  Various types of antenna devices for in-vehicle communication terminals are provided. This is because the in-vehicle communication terminal has various uses, and an antenna device corresponding to the use is provided. For example, recently, an ETC (Electronic Toll Collection) system for toll collection on toll roads is becoming widespread.

  FIG. 5 schematically shows a part of an antenna device for an ETC system. In FIG. 5, the antenna device includes an antenna element 101 made of conductive metal, a ground plate 102 made of conductive metal, and a feed probe 103 made of conductive metal for feeding power by electromagnetic coupling between the antenna element 101. Including. A holding body 104 for holding the antenna element 101 is disposed between the antenna element 101 and the ground plate 102. The holding body 104 is made of an insulating material such as an insulating resin.

  The power feeding probe 103 has a first portion 103-1 rising from the back surface side to the front surface side of the ground plate 102 through a through hole 102 a provided in the ground plate 102, and approximately from the upper end portion of the first portion 103-1. A second portion 103-2 that bends 90 degrees and extends in the lateral direction; and a third portion 103-3 (see FIG. 6) that bends about 90 degrees from the tip of the second portion 103-2 and extends in the lateral direction. Consists of. The second and third portions 103-2 and 103-3 of the power supply probe 103 extend slightly parallel to the lower surface of the antenna element 101 (see, for example, Patent Document 1).

  A lower end portion of the first portion 103-1 in the power supply probe 103 protrudes on the lower surface side of the ground plate 102. The core wire 110-1 of the power supply coaxial cable 110 is connected to the protruding portion by soldering. Needless to say, the core wire 110-1 and the first portion 103-1 of the coaxial cable 110 are not brought into contact with the ground plate 102.

  The coaxial cable 110 is provided so as to follow the lower surface of the ground plate 102, and for this purpose, the holder 120 of the coaxial cable 110 is soldered to the lower surface of the ground plate 102.

  Incidentally, in order to maintain the power supply probe 103 in the state shown in FIG. FIG. 6 shows this guide member.

  In FIG. 6, the guide member 200 has a first leg 201 that extends downward from both ends thereof. The 1st leg part 201 has elasticity, and has the nail | claw part 201-1 for engagement in the lower end part. The guide member 200 is locked to the ground plate 102 by inserting the claw portion 201-1 through the hole 102b provided in the ground plate 102. The guide member 200 is provided with a second leg 202 facing slightly downward from the first leg 201. The guide member 200 is further provided with a third leg portion 203 having a through hole 203a for passing the first portion 103-1 of the power supply probe 103 at the center thereof downward. An L-shaped groove 203b is provided on the upper surface of the guide member 200 from the through hole 203a. The groove 203b accommodates the second portion 103-2 and a part of the third portion 103-3 of the power feeding probe 103.

  The second and third leg portions 202 and 203 are in contact with the upper surface of the ground plate 102 when the claw portion 201-1 is inserted into the hole 102b of the ground plate 102. The guide member 200 is made by integral molding of an insulating resin material, for example.

  In the above antenna device, the power feeding probe 103 is used for electromagnetic coupling with the antenna element 101, and electrical connection with the power feeding cable is performed by soldering. For this reason, not only the number of parts increases, but also the assembly man-hour for soldering also increases. In addition, it is unavoidable that an individual difference is caused by an operator in soldering, and as a result, a power supply loss due to variations in soldering state occurs.

Japanese Patent Laid-Open No. 2001-24428

  An object of the present invention is to provide an antenna device effective for reducing the number of parts.

  Another object of the present invention is to provide an antenna device that eliminates the need for soldering work in a power feeding probe.

  The present invention provides a ground conductor substrate (11), an antenna element (12) provided in a separated state on the surface side of the ground conductor substrate, and the antenna element between the ground conductor substrate and the antenna element. And a feeding probe (25) having a part extending in parallel with a certain distance, and in the antenna device (10) that feeds power by electromagnetic coupling through the feeding probe, for feeding to the back side of the ground conductor substrate The coaxial cable (20) is attached, and only the core wire (21) of the coaxial cable is led out to the surface side of the ground conductor substrate, and a part (21-2, 21-3) of the leading end side of the lead-out portion is The antenna element is bent so as to be parallel to the antenna element, and a part on the tip side also serves as the feeding probe.

  In the antenna device according to the present invention, a guide member (30) made of an insulating material for guiding the core wire is provided between the antenna element and the ground conductor substrate.

  In the antenna device according to the present invention, the core wire portion of the coaxial cable is bent at approximately 90 degrees from the first portion (21-1) rising substantially perpendicularly from the ground conductor substrate and from the tip of the first portion. And a second portion (21-2) extending in parallel with the antenna element and a third portion (21-3) further bent substantially 90 degrees from the tip of the second portion and extending in parallel with the antenna element. And the guide member guides the first part on its side surface, and the second part and at least a part of the third part are substantially L-shaped formed on the upper surface thereof. The groove (30a) guides.

  In the antenna device according to the present invention, a claw (11-1) may be provided by cutting and raising the back surface side of the ground conductor substrate, and the coaxial cable may be held by the claw at the outer conductor portion (22). .

  When the antenna device according to the present invention is installed outside the vehicle, the antenna device includes a bottom cover (51), a dome-shaped top cover (52) attached to the bottom cover, the bottom cover, It is preferably accommodated in a sealed state by a case (50) comprising a gasket (55) sandwiched between top covers. In this case, it is preferable that a recess is provided on the lower surface side of the bottom cover, the plate-like magnet (60) is accommodated in the recess, and the entire lower surface side of the bottom cover is covered with the bottom sheet (53).

  The reference numerals in the parentheses are given for easy understanding of the present invention, and do not limit the present invention.

  Since the antenna device according to the present invention is configured so that a part of the core wire of the coaxial cable acts as a power supply probe, conventional parts dedicated to the power supply probe are unnecessary, and the power supply probe and the core wire of the coaxial cable are not required. Since there is no need for soldering, the cost can be reduced by reducing the number of parts and simplifying the assembly work. Further, since there is no soldering between the power supply probe and the core wire of the coaxial cable, the problem of power supply loss due to variations in the soldering state can be solved.

  A preferred embodiment of an antenna device according to the present invention will be described with reference to FIGS.

  1 and 2, an antenna device 10 according to the present embodiment includes a ground conductor substrate 11 made of a rectangular conductive metal and an antenna element 12 provided on the surface side of the ground conductor substrate 11 in a separated state. Also in the antenna device 10 according to this embodiment, a feeding probe having a portion extending in parallel with the antenna element 12 at a predetermined distance is provided between the ground conductor substrate 11 and the antenna element 12. Then, power is supplied by electromagnetic coupling through this power supply probe. This antenna device is suitable for an ETC antenna device, for example, but is not limited thereto. Further, the shape of the ground conductor substrate 11 is not limited to a rectangular shape, and may be, for example, a circular shape.

  The antenna device 10 according to the present embodiment has a first feature in that a feeding probe is realized by using a core wire of a feeding coaxial cable. The first feature will be described below.

  A power supply coaxial cable 20 is attached to the back side of the ground conductor substrate 11. The covering of the coaxial cable 20 is removed from the tip over a predetermined length. Then, only the exposed core wire 21 is led out through the through hole 11 a provided in the ground conductor substrate 11 so as to be substantially perpendicular to the surface side of the ground conductor substrate 11. Furthermore, a part of the tip end side of the core wire 21 is bent so as to be parallel to the antenna element 12 so that a part of the tip end side functions as a power feeding probe.

  A guide member 30 made of an insulating material for guiding the core wire 21 is provided between the antenna element 12 and the ground conductor substrate 11.

  The core wire 21 of the coaxial cable 20 is bent approximately 90 degrees from the first portion 21-1 rising substantially vertically from the ground conductor substrate 11 and the tip of the first portion 21-1 and extending in parallel to the antenna element 12. The second portion 21-2 includes a second portion 21-2 and a third portion 21-3 that is further bent by about 90 degrees from the tip of the second portion 21-2 and extends parallel to the antenna element 12. A substantially L-shaped portion composed of the second portion 21-2 and the third portion 21-3 is a portion that acts as a power feeding probe. Below, the part which consists of the 2nd part 21-2 and the 3rd part 21-3 may be called the electric power feeding probe 25. FIG.

  The guide member 30 according to the present embodiment guides the first portion 21-1 in the vertical direction on its side surface, and the second portion 21-2 and the third portion 21-3 are substantially L-shaped formed on the upper surface thereof. It guides with the groove | channel 30a.

  In addition, when making the 3rd part 21-3 long, you may make it the front end side protrude from the guide member 30. FIG. In this case, a part of the second part 21-2 and the third part 21-3 is guided by the groove 30a.

  Alternatively, a through hole may be provided in the central portion of the guide member 30 in the vertical direction, and the first portion 21-1 may be guided in the vertical direction through this through hole. In other words, the power feeding probe 25 does not need to be substantially L-shaped, and may be, for example, substantially S-shaped. The first to third portions 21-1 to 21-3 may be guided by a guide member having any shape. Of course, as in the conventional case, the insulation treatment is performed so that the core wire 21 and the ground conductor substrate 11, particularly the portion of the through hole 11 a are not in contact with each other. Furthermore, a holding body for holding the antenna element 12 in parallel with the ground conductor substrate 11 is installed between the ground conductor substrate 11 and the antenna element 12. It may be realized. For this reason, in FIG. 1, the holding body is only indicated by reference numeral 40. A circuit such as an LNA (Low Noise Amplifier) circuit is mounted on the ground conductor substrate 11 while being insulated from the ground conductor substrate 11, but is not shown.

  As described above, the antenna device 10 according to the present embodiment is configured such that a part of the core wire 21 of the coaxial cable 10 acts as the feeding probe 25. Thereby, in this embodiment, parts dedicated to the power feeding probe are unnecessary, and soldering work between the power feeding probe and the core wire of the coaxial cable is also unnecessary.

  As shown in FIG. 3, the second feature of the present embodiment is that a claw 11-1 is provided by cutting and raising the back surface of the ground conductor substrate 11, and the coaxial cable 20 is connected to the mesh-like external conductor portion by the claw 11-1. 22 in that it is held.

  Such a claw 11-1 is easily made by making a substantially U-shaped cut into the ground conductor substrate 11 to form a tongue-like portion and raising the tongue-like portion on the back side of the ground conductor substrate 11. be able to.

  According to such a holding structure, a holder by a separate part for holding the coaxial cable 20 and a soldering operation for fixing it to the ground conductor substrate 11 are unnecessary. Further, since the outer conductor portion 22 of the coaxial cable 20 is held by the claw 11-1, the grounding of the ground conductor substrate 11 can be realized.

  By the way, the ETC antenna device is usually installed in the passenger compartment. Therefore, the conventional ETC antenna device is only accommodated in a simple exterior case, and the waterproof function and the like are omitted.

  On the other hand, the third feature of the antenna device according to the present embodiment is that the antenna device 10 as shown in FIG. 1 has a waterproof structure and can be removably attached to a metal part of the vehicle body by a magnet. .

  The waterproof structure is realized by housing the antenna device 10 shown in FIG. 1 in a case 50 made of a resin material shown in FIG. The case 50 is sandwiched between the bottom cover 51 for mounting the antenna device 10, the dome-shaped top cover 52 that is fitted into the bottom cover 51, and the bottom cover 51 and the top cover 52. The gasket 55 is waterproof so that a sealing structure can be realized. The top cover 52 is provided with a notch 52a for allowing the coaxial cable 20 to pass therethrough. The ground conductor substrate 11 is held and fixed to the upper surface side of the gasket 55 by, for example, screwing the inner wall of the top cover 52 or fitting with a protrusion provided on the inner wall.

  On the other hand, a recess is formed on the upper surface side of the bottom cover 51 and the lower surface side of the gasket 55, and a plate-like magnet 60 is accommodated in the recess. The entire bottom surface of the bottom cover 51 is covered with a bottom sheet 53. The bottom cover 51, the top cover 52, the gasket 55, and the bottom sheet 53 are integrated by screws 54 and the like that are screwed from the bottom surface side of the case 50.

  As described above, by housing the antenna device in the case 50 having the magnet 60, the antenna device can be easily attached to a chassis or the like outside the passenger compartment by a suction method, and has a waterproof function against rainwater or the like. Can do.

  The embodiment of the present invention has been described with respect to a small antenna device suitable for an ETC system. However, the present invention is not limited to an ETC antenna device, but for receiving other satellite waves and terrestrial waves. Applicable to all small antenna devices.

It is a top view which shows schematic structure of the antenna device by embodiment of this invention. It is sectional drawing by line AA 'of the antenna apparatus shown in FIG. It is a perspective view for demonstrating the nail | claw for coaxial cable holding formed in the grounding conductor board | substrate shown by FIG. It is the figure which showed an example of the case for accommodating the antenna apparatus shown by FIG. It is a fragmentary sectional view for demonstrating an example of the conventional antenna device. FIG. 6 is a plan view (FIG. A) and a side view (FIG. B) for explaining a guide member of the power feeding probe shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Antenna apparatus 11, 102 Grounding conductor board | substrate 12, 101 Antenna element 20, 110 Coaxial cable 21 Core wire 25, 103 Feed probe 30, 200 Guide member

Claims (6)

A ground conductor substrate, an antenna element provided in a separated state on the surface side of the ground conductor substrate, and a portion extending between the ground conductor substrate and the antenna element and extending in parallel with a certain distance from the antenna element In an antenna device including a power feeding probe having a power supply by electromagnetic coupling through the power feeding probe,
A coaxial cable for feeding is attached to the back side of the ground conductor substrate, and only the core wire of the coaxial cable is led out to the surface side of the ground conductor substrate, and a part of the leading end side of the lead-out portion is parallel to the antenna element. An antenna device, wherein the antenna device is bent so that a part of the tip side also serves as the feeding probe.   The antenna device according to claim 1, wherein a guide member made of an insulating material for guiding the core wire is provided between the antenna element and the ground conductor substrate.   The core portion of the coaxial cable includes a first portion that rises substantially perpendicularly from the ground conductor substrate, and a second portion that is bent approximately 90 degrees from the tip of the first portion and extends parallel to the antenna element. A third portion that is further bent approximately 90 degrees from the tip of the second portion and extends parallel to the antenna element, and the guide member guides the first portion on its side surface, The antenna device according to claim 2, wherein at least a part of the second portion and the third portion is guided by a substantially L-shaped groove formed on an upper surface thereof.   The antenna device according to any one of claims 1 to 3, wherein a claw is provided by cutting and raising the back surface side of the ground conductor substrate, and the coaxial cable is held by the claw at the outer conductor portion.   The antenna device is housed in a sealed state by a case comprising a bottom cover, a dome-shaped top cover attached to the bottom cover, and a gasket sandwiched between the bottom cover and the top cover. Item 5. The antenna device according to any one of Items 1 to 4. 6. The bottom surface of the bottom cover has a recess, a plate-like magnet is accommodated in the recess, and the entire bottom surface side of the bottom cover is covered with a bottom sheet. Antenna device.

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