JP2009239509A - Directional antenna and antenna system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for mounting a directional antenna appropriately in a member such as a messenger wire extending horizontally. <P>SOLUTION: The directional antenna 10B includes a supporting member 11 and an antenna body 12 formed on a surface of the supporting member 11 and including a plurality of elements disposed along with a predetermined direction. An inner surface of the supporting member 11 is in contact with the messenger wire 5. Namely, the supporting member 11 is configured to be mounted in the messenger wire 5 by being in contact with at least two positions of the messenger wire 5. In the directional antenna, the antenna body 12 is constituted of the plurality of elements. A communication cable 4 is supported on the messenger wire 5 by a metal fitting 6 but an inner diameter of the supporting member 11 (tubular body) has such a size as to pass both messenger wire 5 and the communication cable 4 through the supporting member 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a directional antenna and an antenna system including the same.

  In recent years, wireless communication for automobiles has attracted attention. Examples of wireless communication for automobiles include road-to-vehicle communication that performs communication between a moving vehicle and a wireless device installed beside a road. In such a wireless communication service, a space on a road (hereinafter simply referred to as “road”) is a service area.

  As a method of setting a road as a service area for wireless communication, for example, a method of attaching a radio to a utility pole provided on the side of the road or a messenger wire stretched between the utility poles can be considered. The messenger wire is a wire that supports communication cables, cable broadcasting, CATV cables, and the like for laying them overhead.

For example, Japanese Patent Application Laid-Open No. 2002-50921 (Patent Document 1) discloses a wireless device suspended from a messenger wire and an antenna built in the housing of the wireless device. This wireless device is a parent device used in a 1: N type wireless system, that is, a system in which one parent device communicates with each of a plurality (N) of child devices. Two central feeding antennas (dipole antennas) are built in the casing of the radio. In the above document, it is disclosed that omnidirectionality can be obtained on a horizontal plane by configuring a diversity antenna with two centrally fed antennas.
JP 2002-50921 A

  When building a wireless system that covers an elongated area such as a road, in order to efficiently concentrate radio waves in the service area, for example, it is preferable to install an antenna having directivity in a specific direction on the messenger wire. . However, only the omnidirectional antenna is disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2002-50921.

  An object of the present invention is to provide a technique for suitably attaching a directional antenna to a horizontally extending member such as a messenger wire.

  In summary, the present invention is a directional antenna, a support member configured to be attachable to at least two horizontal members extending in the horizontal direction, and formed on a surface of the support member and arranged in a predetermined direction. And an antenna main body including a plurality of elements.

Preferably, the support member is a cylindrical member formed in a hollow shape and having both ends opened.
Preferably, the antenna main body is an array antenna.

  Preferably, the plurality of elements are provided on a side opposite to the director with respect to the radiator, a radiator for radiating a radio wave, a waveguide for guiding the radio wave from the radiator in a predetermined direction, and And a reflector for reflecting radio waves from the radiator.

  According to another aspect of the present invention, in the antenna system, the horizontal position and the vertical position of the array antenna in a state where the third directional antenna and the support member are attached to the horizontal member. At least one of them includes a displacement detection device that detects a deviation from the original installation position, and a control device that controls a power feeding phase to each of the plurality of elements based on a detection result of the displacement detection device. The control device corrects the directivity of the array antenna so that the directivity of the array antenna becomes the directivity in a state where the array antenna is installed at the original installation position.

  Preferably, the displacement detection device includes a sensor that detects an inclination of the array antenna with respect to the vertical direction.

  Preferably, the array antenna radiates radio waves while receiving radio waves reflected by a reflector provided at a predetermined position. The displacement detection device detects the displacement of the array antenna based on the electric field strength of the reflected wave received by the array antenna.

  ADVANTAGE OF THE INVENTION According to this invention, the antenna which can be attached to the member extended horizontally, such as a messenger wire, and can obtain the directivity of a desired direction is realizable.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a schematic diagram showing utility pole equipment to which a directional antenna according to Embodiment 1 is attached. Referring to FIG. 1, electric pole 1 is attached with electric wire 2, pole transformer 3, and the like, and communication cable 4 is attached. The communication cable 4 is, for example, a telephone line or an optical cable. The messenger wire 5 is for suspending and supporting the communication cable 4.

  FIG. 2 is an enlarged view of the messenger wire 5 and its peripheral portion shown in FIG. Referring to FIG. 2, communication cable 4 is held by metal fitting 6 in a state of being suspended from messenger wire 5.

  The directional antenna according to the first embodiment is attached to the messenger wire 5. Generally, messenger wires between utility poles exist on the side of the road, so that the road can be used as a wireless communication service area by attaching the directional antenna according to the first embodiment to the messenger wire 5.

  FIG. 3 is a diagram showing an example of a service area for wireless communication formed by the directional antenna according to Embodiment 1. With reference to FIG. 3, the utility pole 1 is installed beside the road 8, and a messenger wire (not shown) is stretched between the utility poles. In addition, the arrangement | positioning of the utility pole 1 and the space | interval between utility poles are not specifically limited, Moreover, the extending direction of a messenger wire is not specifically limited.

  The hatched area indicates a wireless communication service area. The service area is formed along the road 8. For example, the wireless communication service area can be formed along the road by attaching the directional antenna according to Embodiment 1 to the messenger wire such that the direction of the directivity is along the road. become.

  Further, according to the first embodiment, it is possible to reduce the number of installed directional antennas as compared to the case where omnidirectional antennas are installed on the messenger wire.

  Here, when a directional antenna is installed on the messenger wire, it is considered necessary to consider at least the following two points. One of them is that the distance between communication cables or the like laid overhead (supported by a messenger wire) is relatively short, for example, about 30 cm, so that the antenna is configured to avoid interference with other messenger wires. That is. The other is that there is a possibility that the directionality of the antenna may be physically fluctuated by the vibration or rotation of the antenna in the horizontal direction (or vertical direction) under the influence of wind or the like. Is to suppress physical variation of directivity.

  FIG. 4 is a diagram for explaining a first point to be considered when a directional antenna is attached to a messenger wire. As shown in FIG. 4, it is assumed that the messenger wires 5A and 5B are stretched at a predetermined vertical interval (for example, 30 cm), and the antennas 20A and 20B are attached to the messenger wire 5A.

  The vertical size of the antenna 20A is smaller than the distance between the messenger wires 5A and 5B. Therefore, interference between the antenna 20A and the messenger wire 5B is avoided. On the other hand, the vertical size of the antenna 20B is larger than the interval between the messenger wires 5A and 5B. Therefore, the antenna 20B interferes with the messenger wire 5B. That is, FIG. 4 shows that in order to attach an antenna to a messenger wire, the shorter the vertical dimension of the antenna in the state of being installed on the messenger wire, the better.

  FIG. 5 is a diagram for explaining a second point to be considered when a directional antenna is attached to a messenger wire. Referring to FIG. 5, antenna 20 </ b> A is attached to be supported at point P on messenger wire 5. As shown in FIG. 5, the axis along the extending direction (major axis direction) of the messenger wire 5 is the X axis, the vertical axis is the Z axis, and the axis perpendicular to both the X axis and the Z axis is Y. Axis. It should be noted that the size of the antenna 20A in the vertical direction satisfies the above requirement.

  When the antenna 20A is attached to the messenger wire 5, the degree of freedom of the attachment position is increased. However, for example, when wind blows, the antenna 20A may vibrate in the X-axis direction or vibrate in the Y-axis direction. Furthermore, when the antenna 20A is suspended from the messenger wire by a string, the antenna 20A may rotate (vibrate) about the Z axis due to twisting of the string or the like. In such a case, since the position of the antenna 20A varies from the original installation position, the radiation direction of the radio wave (beam) from the antenna 20A also changes. That is, the directivity varies in various directions as shown in FIG. In this case, it is expected that it will be difficult to maintain the stability of communication.

  The antenna according to the present embodiment can solve such a problem. Hereinafter, the antenna of this embodiment will be described.

  FIG. 6 is a diagram showing a first configuration example of the directional antenna according to the first embodiment. FIG. 6A shows a state in which the directional antenna according to the first embodiment is attached to a messenger wire. As shown in FIG. 6A, the directional antenna 10 </ b> A includes a support member 11 and an antenna main body 12 formed on the surface of the support member 11.

  In the present embodiment, the support member 11 is formed in a hollow shape, and the antenna main body 12 is formed on the inner surface of the support member 11. However, the antenna main body 12 may be formed on the outer surface of the support member 11.

  The support member 11 includes attachment members 15 that are in contact with two locations of the messenger wire 5. By attaching the attachment member 15 to the messenger wire 5, the support member 11 is attached to the messenger wire 5.

  FIG. 6B is a diagram for explaining that the directivity variation of the directional antenna 10 </ b> A is suppressed by the attachment member 15. As shown in FIG. 6B, since the attachment members 15 are attached to two locations of the messenger wire 5, the directivity of the directional antenna 10A vibrates (rotates) around the Y axis and around the Z axis. It is suppressed. Therefore, even if the directivity fluctuates, the fluctuation can be limited to vibration (rotation) about the X axis.

  FIG. 7 is a diagram showing a second configuration example of the directional antenna according to the first embodiment. Referring to FIG. 7, directional antenna 10 </ b> B includes a support member 11 formed in a cylindrical shape and an antenna main body 12.

  The support member 11 is a cylindrical body that is open at both ends and is hollow. Therefore, the support member 11 can be passed through the messenger wire 5 as shown in FIG. The support member 11 is installed on the messenger wire 5 by suspending the support member 11 through the support member 11 on the messenger wire 5.

  Although the communication cable 4 is supported on the messenger wire 5 by the metal fitting 6, the inner diameter of the support member 11 (cylindrical body) is large enough to allow the messenger wire 5 and the communication cable 4 to pass through the support member 11. Yes. Further, the outer diameter of the support member 11 (cylindrical body) is smaller than the vertical interval (for example, 30 cm) of the messenger wire 5.

  The antenna main body 12 is formed on the surface of the support member 11. Similarly to the first configuration example, the antenna main body 12 is formed on the inner surface of the support member 11, but may be formed on the outer surface of the support member 11.

  FIG. 8 is a view showing a configuration of a mounting portion of the support member 11 to the messenger wire 5. FIG. 8 shows a state in which the support member 11 is viewed along the extending direction (long axis direction) of the support member 11.

  Referring to FIG. 8, support member 11 includes overlapping portions 11A and 11B on which irregularities are formed. As shown in FIG. 8 (A), when attaching the support member 11 to the messenger wire 5, an operation of overlapping the concave and convex portions of the overlapping portions 11A and 11B is performed. Thereby, a hollow cylindrical body is formed. As shown in FIG. 8 (B), a recessed portion is formed on the inner surface of the cylindrical body by the overlapped portions 11A and 11B. By storing the messenger wire 5 in this hollow portion, the support member 11 can be fixed in a state of being suspended from the messenger wire 5.

  7 and 8 also, the inner surface of the support member 11 is in contact with the messenger wire 5. That is, the support member 11 is configured to be attachable to the messenger wire 5 by contacting at least two places of the messenger wire 5. Therefore, similarly to the directional antenna 10A, even if the directivity of the directional antenna 10B varies, the variation should be limited to vibration (rotation) about the extending direction (X axis) of the messenger wire. Can do.

  Note that the attachment member 15 shown in FIG. 6 also has the same configuration as that shown in FIG. That is, the attachment member 15 is a cylindrical body, and is configured so that a messenger wire and a cable supported by the messenger wire can be passed therethrough. Therefore, according to Embodiment 1, when a directional antenna is attached to a messenger wire, interference between the cable supported by the messenger wire and the antenna main body can be prevented.

  Furthermore, according to Embodiment 1, in the state where the directional antenna is attached to the messenger wire, the vertical dimension of the directional antenna (in the case of the directional antenna 10B, the outer shape of the cylindrical body) is It is smaller than the interval between messenger wires adjacent in the vertical direction. Thereby, it is possible to prevent the directional antenna from interfering with messenger wires, cables and the like other than the messenger wire to which the directional antenna is attached.

  Next, the antenna main body 12 will be described. As will be described below, the antenna main body 12 includes a plurality of elements. By feeding power to the plurality of elements, the antenna body 12 functions as a directional antenna. That is, the plurality of elements are configured to be operable as directional antennas.

  FIG. 9 is a diagram illustrating a first example of the antenna main body 12. Referring to FIG. 9, antenna main body 12 includes a plurality of elements 13. When the support member 11 is developed on a plane, the plurality of elements 13 are two-dimensionally arranged on the surface of the support member 11. Specifically, in a state where the support member 11 is expanded in a plane, the plurality of elements 13 are arranged in the extending direction of the support member 11 (long axis direction of the support member 11) and in a direction perpendicular to the extending direction. Be placed. The plurality of elements 13 (antenna body 12) constitute an array antenna.

  FIG. 10 is a diagram showing power feeding to the antenna body 12 shown in FIG. Referring to FIG. 10, power is supplied to each of the plurality of elements 13 from the wireless device 14 (power feeding device). By controlling the feeding phase from the wireless device 14 to each of the plurality of elements 13, the gain direction (directivity) of the antenna body 12, that is, the array antenna, and the antenna gain and sidelobe shape (beam shape) can be arbitrarily set. It becomes possible to control. Note that various known methods can be applied to the method for controlling the feeding phase, and thus will not be described here.

  FIG. 11 is a diagram illustrating an example of directivity of the antenna main body 12 (array antenna). Referring to FIG. 11, for example, the extending direction of support member 11 (that is, the extending direction of messenger wire 5) is defined as the 0 ° direction and the 180 ° direction on the horizontal plane (see FIG. 11A). By controlling the feeding phase of each of the plurality of elements 13, as shown in FIG. 11A, the directivity in the 0 ° direction and the directivity in the 180 ° direction can be obtained, or as shown in FIG. 11B. In addition, directivity in only the 0 ° direction can be obtained. It is also possible to obtain only directivity in the 180 ° direction.

  In the horizontal plane, the directions orthogonal to the extending direction of the support member 11 (messenger wire 5) are defined as the + 90 ° direction and the −90 ° direction. As shown in FIG. 11C, by controlling the feeding phase of each of the plurality of elements 13, directivity in the + 90 ° direction, directivity in the −90 ° direction, and in the + 90 ° direction and the −90 ° direction. Directivity can be obtained.

  Further, by controlling the feeding phase to each of the plurality of elements 13, directivity in an arbitrary direction on the horizontal plane can be obtained. It is also possible to control the directivity in the vertical direction. Specifically, for example, directivity in a diagonally downward direction can be obtained. The same applies to the beam shape.

  FIG. 12 is a diagram illustrating a configuration example for obtaining directivity in the 0 ° direction. Referring to FIG. 12, power from radio device 14 is supplied to each of a plurality of elements 13 via feeder line FD (for example, a coaxial cable). In the example shown in FIG. 12, the feeding phase to each element is controlled by adjusting the length of the feeding line from the radio device 14 to each element 13, for example.

  In the above example, the plurality of elements 13 are two-dimensionally arranged. However, the plurality of elements 13 need not be limited to being two-dimensionally arranged, and may be arranged one-dimensionally. Further, the plurality of elements 13 are not necessarily limited to being arranged along the same direction as the extending direction of the support member 11, for example, along a direction inclined by a predetermined angle with respect to the extending direction of the support member 11. Then, it may be arranged on the surface of the support member 11 in a one-dimensional manner or in a two-dimensional manner. That is, the plurality of elements 13 are arranged along a certain direction, and the arrangement direction and arrangement pattern thereof are determined based on the directivity direction and the beam shape required for the directional antenna.

  As described above, in the first example of the antenna main body, an array antenna is constituted by a plurality of elements. Thereby, the antenna main-body part 12 can be made into a directional antenna. Furthermore, the directivity can be controlled in an arbitrary direction.

  FIG. 13 is a diagram illustrating a second example of the antenna body 12. Referring to FIG. 13, antenna main body 12 is a Yagi antenna, and includes a director 13A, a radiator 13B, and a reflector 13C. The director 13A, radiator 13B, and reflector 13C are formed in an arc shape along the inner surface of the support member 11.

  The radiator 13B radiates radio waves when the power from the wireless device 14 is supplied. The director 13A guides the radio wave radiated from the radiator 13B in a predetermined direction. The reflector 13C is provided on the side opposite to the director 13A with respect to the radiator 13B, and reflects the radio wave radiated from the radiator 13B toward the director 13A. As shown in FIG. 13, the extending direction of the support member 11 is achieved by superimposing the radio wave from the radiator 13B guided by the director 13A and the radio wave from the radiator 13B reflected by the reflector 13C. Sharp directivity can be obtained (this direction is set to 0 ° as in FIG. 11).

  In the second example, the number of elements constituting the antenna main body 12 is not particularly limited. For example, in the Yagi antenna, increasing the number of directors makes the directivity sharp and increases the gain. Thus, for example, the number of directors is determined based on the desired directivity (or desired gain).

  As described above, in the second example of the antenna main body 12, the Yagi antenna is configured by a plurality of elements. Thereby, the antenna main-body part 12 can be made into a directional antenna. Furthermore, since the elements (waveguide 13A, radiator 13B and reflector 13C) constituting the antenna body 12 can be formed along the inner surface of the cylindrical body, the antenna body 12 can be easily formed.

  As shown in these first and second examples, the antenna body 12 is configured as a directional antenna. Therefore, directivity in a desired direction can be obtained in a state where the directional antenna 10A or 10B is installed on the messenger wire. For example, by installing the directional antenna according to the first embodiment so that directivity can be obtained in the direction along the road, a wireless service using the road as a service area can be realized.

[Embodiment 2]
In the second embodiment, an antenna system for controlling the variation in directivity accompanying the displacement of the directional antenna according to the first embodiment will be described.

  In the directional antenna according to the first embodiment, the support member 11 is attached to at least two places of the messenger wire 5. Thereby, the physical fluctuation | variation of the directivity of the antenna is suppressed. However, there is a possibility that the directional antenna vibrates (rotates) around the messenger wire (which changes the directivity).

  In the antenna system according to the second embodiment, when the directional antenna is attached to the messenger wire, at least one of the horizontal position and the vertical position of the directional antenna (array antenna) is shifted from the original installation position. A displacement detecting device for detecting that the Furthermore, the antenna system according to the second embodiment includes a control device that controls the directivity of the array antenna based on the detection result of the detection device.

  Specifically, when the displacement detection device detects that the array antenna vibrates (rotates) about the messenger wire as the central axis, the control device controls the directivity of the array antenna in the direction opposite to the vibration direction. . As a result, even if the array antenna vibrates, its directivity can be controlled so as to be the directivity when the array antenna is installed at the original installation position (position without vibration). it can. Therefore, it is possible to obtain desired directivity even when the array antenna vibrates.

  FIG. 14 is a diagram showing a first configuration example of the antenna system according to the second embodiment. Referring to FIG. 14, the antenna system 100 includes a directional antenna 10 </ b> A, a radio device 14, and a gravity sensor 16. The gravity sensor 16 is installed on the inner surface of the support member 11 provided with the antenna body 12.

  When the directional antenna 10A vibrates around the messenger wire 5, the antenna main body 12 (array antenna) is inclined with respect to the vertical direction. When the antenna body 12 (array antenna) is tilted with respect to the vertical direction, the gravity sensor 16 detects the direction and magnitude of the tilt and outputs the detection result to the phase control device 18.

  The phase control device 18 supplies power to each element 13 based on the detection result of the gravity sensor 16 when power from the wireless device 14 is supplied to each of the plurality of elements 13 included in the antenna body 12. Control the phase of. The phase control device 18 controls the feeding phase to each element 13 so as to cancel the variation in the directivity of the array antenna due to the vibration of the directional antenna 10A. This makes it possible to obtain desired directivity even when the directional antenna 10A vibrates.

  The gravity sensor 16 corresponds to a displacement detection device that detects that the position of the antenna body 12 is shifted from the original installation position. However, the “displacement detection device” is not limited to the gravity sensor as long as it is a sensor that can detect the inclination of the object from the vertical direction, and for example, a gyro sensor can also be used.

  FIG. 15 is a diagram showing a second configuration example of the antenna system according to the second embodiment. Referring to FIG. 15, antenna system 101 differs from antenna system 100 in that it includes phase control device 19 instead of phase control device 18 and does not include gravity sensor 16. Since the configuration of other parts of antenna system 101 is the same as that of antenna system 100, the following description will not be repeated.

  In this configuration example, a reflector 17 for reflecting radio waves radiated from the antenna main body 12 is installed. The antenna main body 12 also receives this reflected wave. The position and inclination of the reflector 17 are determined so that the intensity of the reflected wave received by the antenna body 12 becomes a predetermined intensity when the antenna body 12 is installed at the original position. When the antenna body 12 is tilted with respect to the vertical direction due to vibration, the reception intensity of the reflected wave from the antenna body 12 changes.

  The phase control device 19 includes a detection device 21, a displacement detection device 22, a phase adjuster 23, a circulator 24, and a branching unit 25. Communication is performed by the wireless device 14 including the transmission device 26 and the reception device 27.

  The detector 21 detects a signal (for example, a signal intensity peak) synthesized via the phase adjuster 23 with respect to the reflected wave received by each element 13 of the antenna body 12. The displacement detection device 22 detects the displacement of the antenna body 12 based on the change in the signal intensity detected by the detection device 21, and sends a signal indicating the detection result to the phase adjuster 23.

  The phase adjuster 23 adjusts the feeding phase to each element 13 according to the signal from the displacement detection device 22, and cancels fluctuations in the beam direction due to vibration of the antenna body 12. The directivity of the array antenna is controlled.

  Since the phase adjuster 23 and the displacement detection device 22 constitute a feedback control system for the intensity of the received signal, the directivity of the array antenna can be maintained optimally.

  The circulator 24 guides the power output from the transmitter 26 to the antenna body 12 (each element 13) via the phase adjuster 23 and guides the signal from the phase adjuster 23 to the branching unit 25. The branching unit 25 branches the signal from the circulator 24 into the receiving device 27 and the detection device 21 in two.

  Thus, according to Embodiment 2, even if the directional antenna vibrates, it is possible to suppress the variation in directivity. Therefore, according to the second embodiment, in addition to the effect of the first embodiment, an effect that the stability of communication can be maintained can be obtained.

(Application example)
FIG. 16 is a diagram showing an example of a wireless communication system including a directional antenna according to the present embodiment. Referring to FIG. 16, a repeater 20 for wireless communication is provided at the corners of roads 31 and 32. The repeater 20 collects and distributes traffic information by supplying power to the antenna 10.

  Antenna 10 is a directional antenna according to the first embodiment. As the configuration of the antenna 10, the configuration of the directional antenna 10A or 10B can be adopted. In addition, when the relay machine 20 detects that the antenna 10 is vibrating, the relay machine 20 may control the antenna 10 so as to suppress the variation in directivity. Or you may provide the control apparatus which controls the directivity of a displacement detection apparatus and the antenna 10 separately from the relay machine 20. FIG.

  A vehicle 41 traveling on the road 31 and a vehicle 42 traveling on the road 32 perform wireless communication via the repeater 20 and the antenna 10. For example, when the vehicle 42 approaches the intersection of the roads 31 and 32, the vehicle 42 transmits information indicating that the vehicle has approached the wireless connection. The repeater 20 receives the information via the antenna 10 provided on the road 32 side, and transmits the information wirelessly via the antenna 10 provided on the road 31 side. As shown in FIG. 16, when there is a vehicle 41 traveling on the road 31, the vehicle 41 receives information that the vehicle 42 is approaching the intersection via the antenna 10 provided on the road 31 side.

  Similarly, when the vehicle 41 approaches the intersection of the roads 31 and 32, the vehicle 41 transmits information indicating that it has approached the intersection by radio. The vehicle 42 receives this information via the antenna 10 provided on the road 31 side, the repeater 20, and the antenna 10 provided on the road 32 side. By exchanging information that the vehicles 41 and 42 are approaching the intersection of the roads 31 and 32, the possibility that the vehicles 41 and 42 collide at the intersection of the roads 31 and 32 can be further reduced.

  Note that FIG. 16 is a diagram illustrating a case where vehicles exchange information with each other via a roadside device. However, a wireless communication system to which the antenna 10 is applied is a road-to-vehicle communication in which information is exchanged between the vehicle and the roadside device. May be used. In this case, the vehicle can receive, for example, traffic jam information or accident information transmitted from the traffic control center via the roadside machine.

  In addition, the directional antenna of this invention is comprised so that attachment to the horizontal member extended horizontally is possible. Therefore, the “horizontal member” is not limited to a messenger wire. For example, a rod-like member or the like may be used, or a string-like member may be used. Further, the use of the horizontal member is not limited to use such as cable support.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is the schematic diagram which showed the utility pole installation to which the directional antenna which concerns on Embodiment 1 is attached. It is an enlarged view of the messenger wire 5 shown in FIG. 1 and its peripheral part. 3 is a diagram illustrating an example of a service area for wireless communication formed by a directional antenna according to Embodiment 1. FIG. It is a figure explaining the 1st point which should be considered when attaching a directional antenna to a messenger wire. It is a figure explaining the 2nd point which should be considered when attaching a directional antenna to a messenger wire. 3 is a diagram showing a first configuration example of a directional antenna according to Embodiment 1. FIG. 6 is a diagram showing a second configuration example of a directional antenna according to the first embodiment. FIG. It is the figure which showed the structure of the attachment part to the messenger wire 5 in the supporting member 11. FIG. FIG. 3 is a diagram showing a first example of an antenna main body 12. It is the figure which showed the electric power feeding to the antenna main-body part 12 shown in FIG. It is the figure which showed an example of the directivity of the antenna main-body part 12 (array antenna). It is the figure which showed the structural example for obtaining the directivity of a 0 degree direction. FIG. 6 is a diagram showing a second example of the antenna main body 12. It is the figure which showed the 1st structural example of the antenna system according to Embodiment 2. FIG. It is the figure which showed the 2nd structural example of the antenna system according to Embodiment 2. FIG. It is the figure which showed an example of the radio | wireless communications system containing the directional antenna according to this Embodiment.

Explanation of symbols

  1 electric pole, 2 electric wires, 3 pole transformer, 4 communication cable, 5, 5A, 5B messenger wire, 6 metal fittings, 8, 31, 32 road, 10, 20A, 20B antenna, 10A, 10B directional antenna, 11 support Member, 11A, 11B Overlap, 12 Antenna body, 13 Element, 13A Waveguide, 13B Radiator, 13C Reflector, 14 Radio, 15 Mounting member, 16 Gravity sensor, 17 Reflector, 18, 19 Phase control Device, 20 repeater, 21 detector, 22 displacement detector, 23 phase adjuster, 24 circulator, 25 branching unit, 26 transmitter, 27 receiver, 41, 42 vehicle, 100, 101 antenna system, FD feeder line.

Claims (7)

A support member configured to be attachable to at least two horizontal members extending in a horizontal direction;
A directional antenna comprising: an antenna main body including a plurality of elements formed on a surface of the support member and arranged in a predetermined direction.   The directional antenna according to claim 1, wherein the support member is a cylindrical member formed in a hollow shape and having both ends opened.   The directional antenna according to claim 1, wherein the antenna main body is an array antenna. The plurality of elements are:
A radiator for emitting radio waves,
A director for guiding radio waves from the radiator in a predetermined direction;
The directional antenna according to claim 1, further comprising a reflector provided on a side opposite to the director with respect to the radiator and configured to reflect a radio wave from the radiator. A directional antenna according to claim 3,
A displacement detection device for detecting that at least one of a horizontal position and a vertical position of the array antenna is deviated from an original installation position in a state where the support member is attached to the horizontal member;
A control device that controls a feeding phase to each of the plurality of elements based on a detection result of the displacement detection device;
The control system corrects the directivity of the array antenna so that the directivity of the array antenna becomes directivity in a state where the array antenna is installed at the original installation position. The displacement detector is
The antenna system according to claim 5, further comprising a sensor that detects an inclination of the array antenna with respect to a vertical direction. While the array antenna radiates radio waves, the array antenna receives the radio waves reflected by a reflector provided at a predetermined position,
The antenna system according to claim 5, wherein the displacement detection device detects a displacement of the array antenna based on an electric field intensity of a reflected wave received by the array antenna.

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