JP2009152684A - Antenna power feed apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna power feed apparatus constituting an antenna on a place of good visibility even when an antenna can not be installed owing to an installation space or beauty. <P>SOLUTION: An escape guide lamp 10 is provided with a guide display board 12 formed on an opening surface of a metallic frame body 11. An insulating gap 15 is formed at a center section of the upper surface of the metallic frame body 11 to divide the upper surface into two right and left sections, and a power feed box 16 is attached to the place on which the insulating gap 15 is formed. The power feed box 16 is constituted so that a metallic casing 17 of which the lower side is opened is arranged on an insulating casing 18 and an input/output plug 21 is attached to the metallic casing 17. The input/output plug 21 is constituted so that a center conductor 23 is connected to one side part of the insulating gap 15 by a feed fitting 25 and a feed bolt 26, an outer conductor 22 is connected to the other side part of the insulating gap 15 by the metallic casing 17, an earth fitting 20 and an earth bolt 27, and the metallic frame body 11 of the escape guide lamp 10, on which the insulating gap 15 is formed, is driven as an antenna. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antenna power feeding apparatus for performing services such as mobile communication and broadcasting by using an indoor structure as an antenna in a closed space such as an indoor area, an underground mall, or a subway premises of a building.

  Conventionally, when providing services such as mobile communications and TV broadcasting in closed spaces such as underground shopping malls, subway premises, and department stores, antennas are installed by selecting places such as ceilings and walls with good visibility. (For example, refer to Patent Document 1).

  However, there are many cases where the antenna cannot be installed due to a problem of installation space or an aesthetic problem, and it is not always possible to install the antenna in a place with a good prospect for radio wave propagation, and there is a problem that the service area is limited. there were.

Further, as a known technique related to the present invention, for example, a display device in which an antenna that transmits a radio wave for broadcasting is housed in a guide light device installed in an underground mall, a subway yard, an office building, or the like (for example, Patent Document 2) (Refer to the above)), an access point consisting of an antenna unit and a camera is attached to the guide light, and the access point is connected to an information device via a wireless link, and a designated information device is operated in the event of a disaster, etc. A technique for activating a camera installed in a device is known (see, for example, Patent Document 3).
JP 9-93011 A JP 2007-304658 A JP 2006-304271 A

  When providing services such as mobile communication and TV broadcasting in closed spaces such as underground shopping malls, subway premises, and department stores as described above, it is necessary to select a place such as a ceiling or wall with good visibility and install an antenna However, there is a problem that the antenna is difficult to install or cannot be installed in an optimal place due to a problem of installation space or an aesthetic problem.

  The present invention has been made to solve the above-mentioned problems, and it is a case where there is no installation space or a new antenna cannot be installed due to an aesthetic problem in a closed space such as an underground mall, a subway yard, or a department store. However, an object of the present invention is to provide an antenna feeding device that can configure an antenna in a place with a good view that is advantageous in radio wave propagation.

  An antenna power feeding device according to a first aspect of the present invention is provided in a structure made of a metal frame installed in a closed space, and bisects a side surface of the metal frame to function as an antenna, and the metal A metal power supply box mounted on the insulating gap forming portion of the frame body through an insulator, an input / output plug mounted on the power supply box, and a central conductor of the input / output plug through a power supply fitting Connecting the power supply bolt connected to one side of the insulation gap in the metal frame and the outer conductor of the input / output plug to the other side of the insulation gap in the metal frame via a grounding fitting And a grounding bolt.

  An antenna power feeding device according to a second invention is provided in a structure made of a metal casing installed in a closed space, and allows the metal casing to function as a slot antenna, and a slot of the metal casing A metal power supply box attached to the forming portion via an insulator, an input / output plug attached to the power supply box, and a central conductor of the input / output plug through the power supply fitting. And a grounding bolt for connecting the outer conductor of the input / output plug to the other side of the slot in the metal housing through a grounding metal fitting. It is characterized by.

  According to a third aspect of the present invention, in the antenna power feeding device according to the first or second aspect of the present invention, a matching circuit is provided between the central conductor of the input / output plug in the power feeding box and the power feeding bracket, and the power feeding impedance is required. It is characterized by adjusting to a value.

  According to the present invention, for example, an evacuation guide light or a light guide sign installed in a closed space such as an underground mall, a subway yard, or a department store can be used as an antenna. Even if a new antenna cannot be installed due to a problem with aesthetics or the like, it is possible to configure the antenna in a place with a good view that is advantageous for radio wave propagation.

  In addition, the antenna characteristics can be improved by providing a matching circuit between the central conductor of the input / output plug and the power supply fitting in the power supply box and adjusting the power supply impedance to a required value.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows an external configuration when an antenna power feeding apparatus according to a first embodiment of the present invention is implemented in an evacuation guide lamp, (a) is a front view, and (b) is a side view. FIG. 2A is a front sectional view showing a detailed configuration of the antenna power feeding device according to the embodiment, and FIG. 2B is a top view of the evacuation guide light.

  1 and 2, reference numeral 10 denotes an evacuation guide light installed in a closed space such as an underground mall, a subway yard, or a department store, for example, a rectangular or rectangular metal frame 11 formed of a metal plate such as aluminum. A synthetic resin induction display plate 12 is detachably mounted on one or both of the opening surfaces. The evacuation guide light 10 is a sign that emits light to indicate an emergency exit or an evacuation passage. The guidance display board 12 has a white symbol mark 13 drawn in green on a white background or a ceiling or wall surface with good visibility. Etc. FIG. 2 shows an example in which the evacuation guide lamp 10 is mounted on the ceiling board 14. Although not shown, the evacuation guide lamp 10 is provided with a fluorescent light source, a lighting circuit, and the like.

  The metal frame 11 is provided with an insulating gap 15 at the center of the upper surface as shown in FIG. The insulating gap 15 is provided over the entire width of the metal frame 11 and divides the upper part of the metal frame 11 into left and right. The interval D of the insulating gap 15 is set in a range of about 5 to 10 mm, for example.

  On the upper surface of the metal frame 11, a power supply box 16 is attached to a portion where the insulating gap 15 is provided. As shown in FIG. 2, the power supply box 16 is fixed to an insulating housing 18 in which a metal housing 17 having an open bottom is formed in a substantially U shape by screws 19a and 19b. In this case, on one screw 19b side, a ground metal fitting 20 formed in a substantially L shape is disposed inside the metal housing 17, and one piece thereof is fixed to the metal housing 17 by the screw 19b. The metal casing 17 and the ground metal fitting 20 are electrically connected. The ground metal fitting 20 is provided such that the other piece is positioned on the insulating housing 18.

  Further, the metal casing 17 is provided with an input / output plug 21 at a substantially central portion of the upper surface. The input / output connector 21 is screwed to the metal housing 17, and the outer conductor 22 is electrically connected to the metal housing 17. In addition, the central conductor 23 of the input / output connector 21 is inserted into the inside through an insulator 24 through a through hole provided in the central portion of the metal casing 17 and is formed in a substantially L shape. For example, it is connected by soldering. The power supply fitting 25 is provided such that a piece located below is in contact with the insulating casing 18.

  The insulating casing 18 is disposed on the upper surface of the metal frame 11 with the insulating gap 15 as the center, and is fixed to the metal frame 11 by power supply bolts 26 and ground bolts 27 on both sides of the insulating gap 15. In this case, the power supply bolt 26 is fixed to the metal frame 11 together with the power supply metal fitting 25 positioned on the upper side of the insulating casing 18, and the ground bolt 27 is an L-shaped ground metal fitting positioned on the upper side of the insulating casing 18. 20 and fixed to the metal frame 11. The interval W between the power supply bolt 26 and the ground bolt 27 is set to about λ / 10. Λ is the wavelength of the target radio wave.

  The operation of attaching the power supply box 16 to the metal frame 11 can be performed, for example, by detachably providing the side surface of the metal casing 17. The insulating casing 18 of the power supply box 16 insulates the metal casing 17 from the metal frame 11 and reinforces the metal frame 11 provided with the insulating gap 15. It has a function of keeping D constant.

  When the evacuation guide light 10 is mounted on the ceiling board 14 as shown in FIG. 2, a notch is provided in a part of the ceiling board 14, and the power supply box 16 is disposed in the notch.

  As described above, the metal frame 11 of the evacuation guide lamp 10 is provided with the insulating gap 15 and separated into right and left, so that the metal frame 11 operates as a loop antenna or a folded dipole antenna. The input / output plug 21 provided in the power supply box 16 has a central conductor 23 connected to one end of the metal frame 11, that is, one side of the insulating gap 15 through the power supply fitting 25 and the power supply bolt 26. Then, the outer conductor 22 is connected to the other end of the metal frame body 11, that is, the other side portion of the insulating gap 15 through the metal housing 17, the ground metal fitting 20 and the ground bolt 27.

  Therefore, when power is supplied from the transmitter (not shown) to the input / output connector 21 via the coaxial cable, the supplied power is insulated from the central conductor 23 and the outer conductor 22 of the input / output connector 21 by the insulation gap of the metal frame 11. 15 is transmitted to both ends, and radio waves are radiated from the metal frame 11.

  Since the evacuation guide light 10 is installed in a place with good visibility due to its nature, the antenna is installed in a good place in terms of radio wave propagation, and a wide service area can be secured. Further, by using the metal frame 11 of the evacuation guide light 10 as an antenna, it is not necessary to newly install an antenna. Therefore, it is not necessary to secure an installation place of the antenna, and it is an aesthetic problem. There is nothing.

  Further, the evacuation guide lamp 10 can be used as a transmitting antenna and also as a receiving antenna.

  The length in the longitudinal direction of the metal frame 11 constituting the evacuation guide lamp 10 is preferably close to λ / 2, but there is no particular problem even if it is other length.

  Further, in the above embodiment, even if the already installed evacuation guide light 10 is processed and the power supply box 16 is mounted, or the evacuation guide light 10 is newly manufactured and the power supply box 16 is mounted, the predetermined place You may make it install in.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 3 is a front sectional view showing a detailed configuration when the antenna power feeding apparatus according to the second embodiment of the present invention is implemented in an evacuation guide lamp, and FIGS. 4A to 4C are configurations of the matching circuit in FIG. It is a figure which shows an example.

  The antenna power feeding device according to the second embodiment includes a matching circuit 30 between the center conductor 23 of the input / output plug 21 and the power feeding bracket 25 in the power feeding box 16 in the first embodiment shown in FIGS. And the feeding impedance is adjusted to match the required value.

  As the matching circuit 30, for example, a filter circuit in which a high-frequency coil L and a capacitor C are combined as shown in FIGS. In addition to the configuration shown in FIG. 4, the matching circuit 30 may have any combination according to the configuration content of the evacuation guide lamp 10 and the like.

  According to the second embodiment, the same effects as those of the first embodiment can be obtained, and the feeding impedance can be further matched by the matching circuit 30, and the antenna characteristics can be improved.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG.

  FIGS. 5A and 5B show a configuration example when the antenna power feeding device according to the present invention is implemented on the light guide sign 31. FIG. 5A is a partial cross-sectional front view, and FIG. 5B is a side view. . In addition, since the electric power feeding box 16 in this 3rd Embodiment is the structure similar to what was shown in 1st Embodiment, detailed description is abbreviate | omitted.

  For example, a synthetic resin guide display plate 33 is detachably mounted on one or both opening surfaces of a rectangular metal frame 32 formed of a metal plate. The light guide sign 31 is installed on a ceiling, a wall surface or the like with good visibility in a closed space such as an underground mall, a subway yard, or a department store.

  A guide sign is drawn on the guide display plate 33, and is displayed electronically by a light source such as a fluorescent lamp provided in the metal frame 32. Note that the guide display board 33 may be configured so that the guide sign itself emits light using, for example, an LED (light emitting diode) or the like, in addition to the one that is displayed electronically by an internal light source.

  And the said metal frame 32 is provided with the insulation gap 15 over the full width in the center part of the upper surface like 1st Embodiment, and the upper part of the metal frame 32 is divided into right and left. On the upper surface of the metal frame 32, a power supply box 16 is attached to a portion where the insulating gap 15 is provided, and fixed on both sides of the insulating gap 15 using power supply bolts 26 and ground bolts 27. In this case, as shown in FIG. 2 of the first embodiment, the central conductor 23 of the input / output plug 21 is connected to one side portion of the insulating gap 15 via the power supply fitting 25 and the power supply bolt 26 to input / output. The outer conductor 22 of the plug 21 is connected to the other side of the insulating gap 15 through the metal casing 17, the grounding metal 20 and the grounding bolt 27.

  Since the light guide sign 31 is installed in a closed space such as an underground shopping area in a place with a good visual line of sight, the metal frame 32 is used as an antenna to obtain an advantageous condition for radio wave propagation. The same effect as in the first embodiment, that is, in a place where there is no prospective location that is advantageous for radio wave propagation even when there is no antenna installation space or when a new antenna cannot be installed due to aesthetic problems. The effect that an antenna can be configured can be obtained.

  In the third embodiment, as in the second embodiment, a matching circuit is provided between the center conductor 23 of the input / output connector 21 and the power supply fitting 25 in the power supply box 16 to adjust the power supply impedance to a required value. You may make it do.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG.

  FIG. 6 shows a configuration when the antenna power feeding device according to the present invention is implemented on a metal window frame, where (a) is a front view and (b) is a side view.

  The antenna feeding apparatus according to the fourth embodiment shows a configuration example in the case where the antenna feeding apparatus is implemented on a metal window frame 36 of a window 35 used in a store or the like in a closed space such as an underground mall, a subway yard, or a department store. Since the power supply box 16 has the same configuration as that shown in the first embodiment, a detailed description thereof will be omitted.

  The window 35 has a window glass 37 attached to a metal window frame 36, and is installed in a space provided in a wall 38 as shown in FIG. An insulating gap 15 is provided at one side of the metal window frame 36, for example, at the center of the upper side, and the upper side of the metal window frame 36 is divided into right and left. Then, the power supply box 16 is mounted on the metal window frame 36 above the portion where the insulating gap 15 is provided. In this case, the power supply box 16 is attached to the metal window frame 36 so that the power supply bolt 26 and the ground bolt 27 are positioned on both sides of the insulating gap 15 as in the first embodiment. The power feeding box 16 is disposed inside a wall 38 that supports the metal window frame 36 as shown in FIG.

  As described above, the insulating gap 15 is provided in the metal window frame 36 constituting the window 35, and the metal window frame 36 is used as a loop antenna or a folded antenna by supplying power to both sides of the insulating gap 15 through the power supply box 16. Works well.

  Since the window 35 is used in a store or the like in a closed space such as an underground mall and is often installed in a place with a good visual line of sight, by using the metal window frame 36 as an antenna, Advantageous conditions can be obtained, and effects similar to those of the first embodiment can be obtained.

  In the fourth embodiment, as in the second embodiment, a matching circuit is provided between the central conductor 23 of the input / output connector 21 and the power supply fitting 25 in the power supply box 16 to adjust the power supply impedance to a required value. You may make it do.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described with reference to FIGS.

  FIG. 7 shows a configuration example when the antenna power feeding device according to the present invention is implemented on an electric signboard, in which (a) is a partially sectional front view and (b) is a side view. FIG. 8 is a side sectional view showing a detailed configuration of the antenna power feeding device according to the embodiment.

  The antenna power feeding apparatus according to the fifth embodiment is shown as an example of the case where the antenna power feeding apparatus is implemented on an electric signboard 41, and the power feeding box 16 has the same configuration as that shown in the first embodiment. Are denoted by the same reference numerals, and detailed description thereof is omitted.

  The electric signboard 41 has an open front surface of a box-shaped metal casing 42, and an electric display panel 43 is detachably mounted on the opening surface. A lightning device using, for example, an LED (light emitting diode) or the like is mounted on the lightning display plate 43 and the metal housing 42, and is configured so that lightning display can be performed on the lightning display plate 43. The electric signboard 41 is installed in a place with a good visibility in a closed space such as an underground mall, a subway yard, and a department store. FIG. 8 shows an example in which the electric signboard 41 is installed on the wall 45 in the closed space.

  The bottom plate 42a of the metal casing 42 is provided with a slot 44 in a horizontal direction or a vertical direction at a position that does not hinder the lightning device. The slot 44 is set to have a width of about 5 to 10 mm and a length of about λ / 2, for example. The length of the slot 44 is preferably set to about λ / 2, but may be other values. The direction of the slot 44 is determined by the polarization direction of the radio wave to be used, that is, whether it is horizontal polarization or vertical polarization.

  In addition, the power supply box 16 is disposed on the bottom plate 42 a of the metal housing 42 so as to be positioned at the center portion of the slot 44 on the back side. In this case, the power supply box 16 fixes the insulating housing 18 to the bottom plate 42 a of the metal housing 42 such that the power supply bolt 26 is positioned above the slot 44 and the ground bolt 27 is positioned below the slot 44. . It should be noted that the positional relationship between the power supply bolt 26 and the ground bolt 27 may be any, and can be arbitrarily set.

  When the light sign 41 is mounted on the wall 45 as shown in FIG. 8, a notch is provided in a part of the wall 45, and the power supply box 16 is provided in the notch.

  As described above, the slot 44 is provided in the bottom plate 42a of the metal casing 42 that constitutes the light sign 41, and power is supplied to both sides of the central portion of the slot 44 via the power supply box 16, thereby forming the light sign 41. The metal housing 42 that operates as a slot antenna works well.

  Since the electric signboard 41 is installed in a closed space such as an underground shopping area in a place with a good visual line of sight, it is possible to obtain advantageous conditions for radio wave propagation by using the metal casing 42 as an antenna. And the same effects as those of the first embodiment can be obtained.

  In the fifth embodiment, as in the second embodiment, a matching circuit is provided between the central conductor 23 of the input / output connector 21 and the power supply fitting 25 in the power supply box 16 to adjust the power supply impedance to a required value. You may make it do.

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described with reference to FIGS.

  FIG. 9 is a front view showing a configuration example when the antenna feeding device according to the present invention is implemented on a self-supporting guide plate, and FIG. 10 is a side sectional view showing a detailed configuration of the metal casing of the guide display portion in FIG. .

  In FIG. 9, 51 is a self-supporting guide plate, and both sides of the guide display unit 52 are held by self-supporting columns 53a and 53b. The guidance display unit 52 performs guidance display on the front side of the guidance display unit metal casing 54. The guide display part metal casing 54 is provided, for example, such that a side plate can be opened and closed.

  A slot 44 having a predetermined length is provided, for example, in a horizontal direction on the back plate 54a of the guide display unit metal casing 54, and the power supply box 16 is disposed on the inner surface of the back plate 54a so as to be positioned at the center of the slot 44. Installing. In this case, for example, the power supply box 16 has the insulating casing 18 placed on the back plate of the guide display section metal casing 54 so that the power supply bolt 26 is positioned below the slot 44 and the ground bolt 27 is positioned above the slot 44. It fixes to 54a.

  In the sixth embodiment, as shown in FIG. 10, an input / output plug 21 is provided on the lower surface of the metal housing 17 of the power supply box 16, and the center conductor 23 is soldered to one end of the power supply fitting 25. Connected by attaching. The other end of the power supply fitting 25 is fixed to the back plate 54 a of the guide display metal casing 54 by a power supply bolt 26. Further, one end of the ground metal fitting 20 is fixed to the upper inner side of the metal housing 17 with a screw 19 b, and the other end of the ground metal fitting 20 is fixed to the back plate 54 a of the guide display portion metal housing 54 with a ground bolt 27.

  The power supply box 16 according to the sixth embodiment is provided with an input / output plug 21 on the lower side of the metal housing 17, but the other configuration is the same as that of the power supply box 16 shown in the first embodiment. ing.

  As described above, the slot 44 is provided in the back plate 54a of the metal housing 54 of the guide display portion metal part 54 constituting the guide display portion 52 of the self-supporting guide plate 51, and power is fed via the power supply box 16 on both sides of the central portion of the slot 44. As a result, the guide display portion metal casing 54 operates favorably as a slot antenna.

  The self-supporting guide plate 51 is often installed in a visually observable place in a closed space such as an underground shopping center, and the use of the guide display portion metal casing 54 as an antenna is advantageous in radio wave propagation. The conditions can be obtained, and the same effect as in the first embodiment can be obtained.

  In the sixth embodiment, since the power supply box 16 is housed in the guidance display unit metal casing 54, the power supply box 16 can be easily implemented even when the installation location of the power supply box 16 cannot be secured. The power supply box 16 does not become an aesthetic problem.

  In the sixth embodiment, as in the second embodiment, a matching circuit is provided between the central conductor 23 of the input / output connector 21 and the power supply fitting 25 in the power supply box 16 to adjust the power supply impedance to a required value. You may make it do.

  In the first to fifth embodiments, the case where the power supply box 16 is provided outside the structure such as the evacuation guide lamp 10 has been described. However, as shown in the sixth embodiment, power is supplied to the inside of the structure. A box 16 may be provided.

  Further, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage.

The external appearance structure at the time of implementing the antenna electric power feeder which concerns on 1st Embodiment of this invention in an evacuation guide lamp is shown, (a) is a front view, (b) is a side view. (A) is front sectional drawing which shows the detailed structure of the antenna electric power feeder which concerns on the embodiment, (b) is a top view of an evacuation guide light. It is front sectional drawing which shows the detailed structure at the time of implementing the antenna electric power feeder which concerns on 2nd Embodiment of this invention in an evacuation guide lamp. It is a figure which shows the structural example of the matching circuit in the embodiment. The example of a structure at the time of implementing the antenna electric power feeder which concerns on 3rd Embodiment of this invention to an electrooptic guide sign is shown, (a) is a front view which shows a partial cross section, (b) is a side view. The structure at the time of implementing the antenna electric power feeder which concerns on 4th Embodiment of this invention in a metal window frame is shown, (a) is a front view, (b) is a side view. The example of a structure at the time of implementing the antenna electric power feeder which concerns on 5th Embodiment of this invention in an electric signboard is shown, (a) is a front view which shows a partial cross section, (b) is a side view. It is side surface sectional drawing which shows the detailed structure of the antenna electric power feeder which concerns on the same embodiment. It is a front view which shows the structural example at the time of implementing the antenna electric power feeder which concerns on 6th Embodiment of this invention in a self-supporting guide plate. It is side surface sectional drawing which shows the detailed structure of the guidance display part metal housing | casing in the same embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Evacuation guide light, 11 ... Metal frame, 12 ... Guidance display board, 13 ... Symbol mark, 14 ... Ceiling board, 15 ... Insulation gap, 16 ... Feeding box, 17 ... Metal enclosure, 18 ... Insulation enclosure 19a, 19b ... screws, 20 ... grounding fitting, 21 ... input / output plug, 22 ... outer conductor of input / output plug, 23 ... central conductor of input / output plug, 24 ... insulator, 25 ... power supply fitting, 26 DESCRIPTION OF SYMBOLS ... Feed bolt, 27 ... Earth bolt, 30 ... Matching circuit, 31 ... Lightning guide sign, 32 ... Metal frame, 33 ... Guide display board, 35 ... Window, 36 ... Metal window frame, 37 ... Window glass, 38 ... Wall, 41 ... Electric signboard, 42 ... Metal casing, 42a ... Bottom plate of metal casing, 43 ... Electric display board, 44 ... Slot, 45 ... Wall, 51 ... Self-supporting guide board, 52 ... Guide display section 53a, 53b, self-supporting pillars, 54, a guide display section metal casing, 54 ... the back plate of the guide display unit metal housing.

Claims (3)

  An insulating gap provided in a structure made of a metal frame installed in a closed space, which bisects the side surface of the metal frame and functions as an antenna, and an insulator in an insulating gap forming portion of the metal frame One of the insulating gaps in the metal frame through the power supply fitting, the metal power supply box mounted through the power supply box, the input / output plug mounted in the power supply box, and the central conductor of the input / output plug through the power supply fitting And a grounding bolt for connecting the outer conductor of the input / output plug to the other side of the insulating gap in the metal frame through a grounding metal fitting. An antenna power feeding device.   Provided in a structure composed of a metal casing installed in a closed space, and a slot that allows the metal casing to function as a slot antenna, and is attached to a slot forming portion of the metal casing via an insulator A metal power supply box, an input / output plug attached to the power supply box, and a power supply for connecting a central conductor of the input / output plug to one side of the slot in the metal casing through a power supply fitting An antenna power feeding apparatus comprising: a bolt; and an earth bolt for connecting an outer conductor of the input / output connector to the other side of the slot in the metal casing through an earth metal fitting.   3. The antenna feeding device according to claim 1, wherein a matching circuit is provided between the central conductor of the input / output plug and the feeding bracket in the feeding box, and the feeding impedance is adjusted to a required value.

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