JPH07263937A - Antenna system for moving body communication - Google Patents

Abstract

PURPOSE:To provide the antenna system which communicates with a moving body without using an LCX cable and reduces the transmission loss to perform the service in a wide range. CONSTITUTION:In the antenna system, an antenna equipment 17 where an inner conductor contact pin 23 and an outer conductor contact part 24 are perpendicularly provided on the upper face of a device main body 21 incorporating a matching device and an antenna element 25 is attached to the side face of the main body 21 is attached in a desired position of a coaxial cable 12 which is laid in the place where it is difficult for a radio wave to propagate. The contact pin 23 pierces an insulating sheath 16, etc., of the coaxial cable 12 in order and has the front end part screwed into an inner conductor 13 and electrically connected. The contact part 24 pierces the insulating sheath 16, etc., of the coaxial cable 12 in the same manner and has the front end part thrust into an outer conductor 15 and surely connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna system for mobile communication, particularly in a place where radio waves are hard to propagate,
The present invention relates to a system for communicating with a mobile body without using a leaky coaxial cable.

[0002]

2. Description of the Related Art Recently, car phones, mobile phones, pagers, etc. have been remarkably widespread, and secure communication with mobile radio in places where radio waves are difficult to propagate, such as in tunnels, underground malls, and reinforced concrete buildings. There is an urgent need.

Conventionally, as a communication system for the purpose of servicing a mobile body in a radio wave non-propagation zone, a radio wave transmission / reception system using a leaky coaxial cable (LCX cable) has been widely used due to its stable characteristics and easy control. Has been. FIG. 4 shows a communication system using an LCX cable. In the figure, reference numeral 1 is an outdoor antenna, 2 is a coaxial cable, 3 is a relay amplifier installed in a radio wave non-propagation zone such as underground, 4 is a distributor, and 5 is an LCX cable. Are shown respectively.

Further, as shown in an enlarged view in FIG. 5, the LCX cable 5 has an insulator 7 made of a polyethylene string 7a and a polyethylene pipe 7b and an aluminum tape on the outer circumference of an inner conductor 6 made of a copper or aluminum pipe. It has a structure in which an outer conductor 8 vertically attached and a sheath 9 of polyethylene or the like are sequentially provided, and a special radio wave leakage hole called a slot 10 is zigzagly formed in the outer conductor 8. In addition, the code | symbol 11 in the figure has shown the messenger wire.

[0005]

As described above, the LCX cable conventionally used in the mobile communication system is as follows.
Since the signal is transmitted and received through the slot 10 of the outer conductor 8 by leaking the signal to the outside as a radio wave, the frequency of the transmission signal is 1 GHz.
When it is increased to a certain degree, the transmission loss becomes very large, making it difficult to construct a wide range system. Further, since it has a messenger wire 11 and has a gourd-shaped cross section, not only is it heavy, but the laying method is limited to the method of suspending it by the messenger wire 11 and there is a problem that it is difficult to lay it. Furthermore, since it is configured to radiate radio waves from the slots 10 of the outer conductor 8 which are continuously arranged along the longitudinal direction of the cable, some slots are provided at each position along the cable. The radio waves radiated from 10 were overlapped, and there were many unnecessary losses in terms of energy. Then, it is conceivable to widen the interval at which the slots 10, which are the radiation points of radio waves, are arranged to reduce the above-mentioned loss by that amount.
It was almost impossible from the structure of CX cables and system theory.

The present invention has been made in order to solve these problems and uses an LCX cable to communicate with a mobile unit without using a leaky coaxial cable (LCX cable) to reduce transmission loss. It is an object of the present invention to provide an antenna system capable of performing the same service as in the case.

[0007]

A mobile communication antenna system according to the present invention comprises an apparatus main body having a matching circuit incorporated therein,
An antenna device having an inner conductor contact pin and an outer conductor contact portion projecting from the device body in the same direction, and an antenna device, the antenna device being attached to a desired position of a coaxial cable, and the inner conductor of the antenna device. The contact pin is connected to the inner conductor by sequentially penetrating the insulating sheath of the coaxial cable, the outer conductor, and the insulator, and the outer conductor contact portion is pierced by the insulating sheath of the coaxial cable to be connected to the outer conductor. It is characterized by

[0008]

In the antenna system of the present invention, the antenna device provided with the matching circuit and the antenna element is directly attached to a desired position of the ordinary coaxial cable laid in the radio wave non-propagation zone, and the antenna device protrudes from the main body of the antenna device. At the same time that the provided inner conductor contact pin penetrates the outer portion of the coaxial cable and comes into contact with the inner conductor, the outer conductor contact portion projecting in the same direction as the contact pin has an insulating sheath of the coaxial cable. Is pierced and is brought into contact with the outer conductor. In this way, the inner conductor contact pin and the outer conductor contact portion of the antenna device are securely connected to the inner conductor and the outer conductor of the coaxial cable, respectively, and these ends are passed through the matching circuit incorporated in the main body of the antenna device to form the antenna. Since it is connected to the element, it is possible to freely perform radio wave communication with a moving body such as an automobile or a train in a radio wave non-propagation zone. In addition, the system is constructed by appropriately attaching the antenna device only to the required portions of the coaxial cable, and unnecessary radio waves are not emitted, so that energy is not wasted.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram schematically showing an embodiment of a mobile communication antenna system according to the present invention.
FIG. 4 is an enlarged view showing a cross section of a main part (shown by A).

In these drawings, reference numeral 12 denotes a coaxial cable laid in a radio wave non-propagation area such as underground or in a tunnel. As shown in FIG. 2, this cable is an inner conductor 13 made of, for example, a copper wire. An outer conductor 1 of a laminated tape formed by laminating an insulating material 14 such as foamed polyethylene and a copper braid or a polyester tape on a copper tape on the outer periphery of
5 is provided in order, and a sheath 16 made of polyethylene, polyvinyl chloride or the like is provided on the outermost side. An antenna device 17, which will be described in detail below, is appropriately attached to a desired position of the coaxial cable 12 so as to transmit and receive radio waves. In FIG. 1, reference numeral 18 is an outdoor antenna, 19 is a relay amplifier, and 20 is a distributor.

The antenna device 17, as shown in FIG.
A box-shaped antenna device main body 21 in which a matching device (not shown) is built-in and whose upper surface is formed into a concave curved surface, and a peripheral surface of a sharp pointed end which is vertically projected on the upper surface Part 22
And an inner conductor contact pin 23 formed with an inner conductor contact pin 23 and a circular ring formed in a sawtooth shape with a sharp tip protruding from the upper surface of the apparatus main body 21 so as to concentrically surround the base of the inner conductor contact pin 23. Outer conductor contact portion 24 of
And a dipole type antenna element 25 vertically attached to the side surface of the device main body 21. Connected to each section. Then, the inner conductor contact pin 23
The insulating sheath 16 of the coaxial cable 12, the outer conductor 15, and the insulator 14 are sequentially pierced in order to form a sharp screw portion 2 at the tip.
2 is screwed into the inner conductor 13, and the outer conductor contact portion 24 is connected to the insulating sheath 16 of the coaxial cable 12.
The outer conductor 15 is pierced by the end of the coaxial cable 12 and the inner conductor contact pin 23 and the outer conductor contact portion 24 are reliably connected to the inner conductor 13 and the outer conductor 15 of the coaxial cable 12, respectively.

In the antenna system of the embodiment thus constructed, the antenna device 17 attached to the coaxial cable 12 enables free radio communication with a moving body such as a car or a train even in a radio wave non-propagation zone. be able to. Further, since the upper surface of the antenna device body 21 is formed in a concave curved surface, the upper surface of the device body 21 is attached to the coaxial cable 12 with the antenna device 17 attached.
It is in close contact with the outer peripheral surface without gaps, and is compact and difficult to come off.
Furthermore, since the system is constructed by appropriately attaching the antenna device 17 to the required portion of the coaxial cable 12, unnecessary radio waves are not emitted and energy is wasted less. Therefore, it is possible to provide a much wider range of transmission / reception services as compared with the conventional communication system using the LCX cable. Further, the coaxial cable 12 used in the present invention can be laid relatively freely without being restricted by the LCX cable, and the laying is easy. Furthermore, since a distributor is not used for each antenna, it is economically advantageous as compared with other antenna devices.

In the embodiment, the antenna element 2
Although a dipole type antenna is used as the antenna 5, it is not limited to this, and a Yagi antenna can be used. That is, as the antenna element 25, a more ideal one can be selected and used from the directivity, gain, frequency and the like.

[0015]

As described above, in the antenna system according to the present invention, the antenna device directly attached to the coaxial cable laid in the service range where the radio wave is hard to propagate can be used for the desired radio wave communication with the moving body. You can do it freely in place. Further, according to the system of the present invention, unnecessary radio waves are not emitted and energy is not wasted, so that a much wider range of transmission / reception services can be provided as compared with the conventional communication system using the LCX cable. it can. Furthermore, since no distributor is used, there are great economic advantages.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an embodiment of an antenna system for mobile communication of the present invention.

FIG. 2 is a lateral cross-sectional view showing an enlarged main part of the embodiment.

FIG. 3 is an enlarged perspective view showing an antenna device used in the embodiment.

FIG. 4 is a diagram schematically showing a conventional communication system using an LCX cable.

FIG. 5 is a perspective view showing an example of the structure of an LCX cable.

[Explanation of symbols]

 12 ... Coaxial cable 13 ... Inner conductor 14 ... Insulator 15 ... Outer conductor 16 ... Insulation sheath 17 ... Antenna device 21 ... Antenna device body 23 ... Inner conductor contact Pin 24 ………… External conductor contact part 25 ………… Antenna element

Claims (4)

[Claims] 1. An antenna device including a device main body having a matching circuit built-in, an inner conductor contact pin and an outer conductor contact portion projecting from the device main body in the same direction, and an antenna element, wherein a desired coaxial cable is provided. And the inner conductor contact pin of the antenna device is connected to the inner conductor by sequentially penetrating the insulating sheath of the coaxial cable, the outer conductor, and the insulator, and connecting the outer conductor contact portion to the inner conductor. An antenna system for mobile communication, characterized in that an insulating sheath of a coaxial cable is pierced and connected to an external conductor. 2. The outer conductor contact portion of the antenna device has an annular shape with a sharp saw-toothed tip, and is concentrically provided around the base of the inner conductor contact pin. 1. The mobile communication antenna system according to 1. 3. The antenna system for mobile communication according to claim 1 or 2, wherein a mounting surface of the inner conductor contact pin of the antenna device body is formed into a curved shape in conformity with the outer peripheral shape of the coaxial cable. 4. The mobile communication antenna system according to claim 1, wherein the antenna element is of a dipole type or a Yagi type.