KR100761597B1 - A broadband leaky coaxial cable - Google Patents

Abstract

The present invention discloses a leaky coaxial cable for vertical polarization. The vertically polarized leakage coaxial cable according to the present invention includes a leaky coaxial cable in which electromagnetic waves are radiated to the outside atmosphere by the application of a signal voltage, comprising: an inner conductor; A dielectric that compactly surrounds the inner conductor with a centerline; And an outer conductor that compactly surrounds the dielectric and has a plurality of radiating slots arranged at equal intervals along the center line, wherein the radiating slot is spaced apart from the first slot and the first slot having a predetermined length. A plurality of second slots spaced apart from each other and symmetrically inverted in the longitudinal direction are arranged along a center line in a repeated zigzag shape to radiate electromagnetic waves to the outside.

According to the present invention, various slot groups can be formed by discontinuous zigzag radial slots in the longitudinal direction of the outer conductor, and it is easy to expand the frequency bandwidth for vertical polarization.

Broadband, Polarized, Slotted, Leakage Coaxial Cable

Description

A broadband leaky coaxial cable

The following drawings, which are attached to this specification, illustrate exemplary embodiments of the present invention, and together with the detailed description of the present invention, serve to further understand the technical spirit of the present invention. It should not be construed as limited to.

1 is a perspective view schematically showing the structure of a leaky coaxial cable according to the prior art;
Figure 2 shows the electric field pattern of the leaky coaxial cable according to the prior art.

Figure 3 is a perspective view schematically showing the structure of a leaky coaxial cable according to a preferred embodiment of the present invention.
4 is a perspective view showing another form of a slot group formed in the leaky coaxial cable of FIG.
5 is a perspective view showing another form of a slot group formed in the leaky coaxial cable of FIG .

<Description of Major Reference Marks in Drawing>

100 ... Leakage coaxial cable 110 ... Inner conductor

120 ... Dielectric 130 ... External conductor

141, 142, 143, 144 ... radiation slot

150 ... shell 200 ... signal generator

The present invention relates to a wideband leakage coaxial cable, and more particularly, to provide a wideband leakage coaxial cable capable of widening without additional slots by improving the slot structure of the leaky coaxial cable.

Generally, a leaky coaxial cable (Leaky Coaxial) is used in a place where a radio frequency (hereinafter referred to as RF) cannot be sufficiently transmitted and received by a discrete antenna such as a tunnel, underground railway, underground building, and an enclosed space. Cable) is used. Here, the leaky coaxial cable serves as a transmission line and an antenna at the same time.

Leakage coaxial cable is a cable that allows radio waves to be radiated through a plurality of slots provided along a longitudinal direction, and can freely design characteristic frequencies by adjusting slot periods or shapes, and shading radio waves of any shape. It is easy to lay in the area.

These leaky coaxial cables could only be used in the FM, Pager, and Cellular bands. However, as mobile services have recently evolved to broadband frequencies, leaky coaxial cables for wideband RF (e.g., RFCX and RFCL) can carry up to the UHF band. Is being used.

The leakage coaxial cable for wideband RF is designed to form a radiation mode corresponding to various frequency bands, and is applied to a system capable of communicating with a central control station or an external base station. Here, the above-described system uses a bandwidth including up-link and down-link frequency ranges, that is, frequency bands in the forward and reverse directions.

The structure and electric field pattern of the aforementioned leaky coaxial cable will be described with reference to FIGS. 1 and 2 as follows.

As shown in FIG. 1, the leaky coaxial cable 10 comprises an inner conductor 1, an insulator 2, an outer conductor 3 and an outer sheath 4 from the center. The outer conductor 3 here is perpendicular to the longitudinal direction and forms slots 4 spaced at regular intervals. The slot 4 is a rectangular groove having a predetermined length.

When a signal voltage is applied between the inner conductor 1 and the outer conductor 3 of the leaky coaxial cable 10 by using the signal generator 20, electromagnetic waves are radiated through the slot 4. The radiation pattern of the electric field will be described with reference to FIG. 2.

As shown in FIG. 2, the radiation direction of the electromagnetic field according to the distribution of the radiated electromagnetic field of the leaky coaxial cable 10 forms a predetermined angle θ with the vertical axis of the leaky coaxial cable 10, whereby electromagnetic waves radiate to the outside. do. Here, the angle θ formed between the vertical axis of the leaky coaxial cable 10 and the traveling direction of the electromagnetic wave may radiate a uniform electromagnetic wave having a small fluctuation of a signal when approaching zero. On the other hand, the radiation angle and the single mode frequency band can be adjusted according to the pitch p between the slots 4, and outside of this band, signal distortion occurs by the second to Nth harmonic modes.

In order to use the aforementioned leaky coaxial cable more efficiently in a wireless terminal based on vertical polarization, a technique related to a vertically polarized leaky coaxial cable capable of radiating an electric field of vertical polarization has been proposed. A leaky coaxial cable for generating vertical polarization by arranging slots in a 'c' shape is disclosed. Japanese Laid-Open Patent Publication No. 2003-273641 discloses a technique for generating vertical polarization by tilting a slot in an axial direction.

However, the leaky coaxial cable disclosed in U.S. Patent No. 5,809,429 has a weakness in that it is difficult to form various slot groups for broadband, and the technique disclosed in Japanese Patent Laid-Open No. 2003-273641 includes a horizontal polarization component to provide a tunnel. There is a problem of deterioration in the properties.

The present invention was devised in view of the above-described conventional problems, and improves the geometry of the slot formed in the outer conductor of the leaky coaxial cable, thereby making it possible to vertically polarize the wireless terminal based on vertical polarization to facilitate bidirectional communication. It is an object of the present invention to provide a leaky coaxial cable.

The vertically polarized leakage coaxial cable according to the present invention for achieving the above object, the leakage coaxial cable in which electromagnetic wave (Electromagnetic Wave) is radiated to the outside atmosphere by the application of a signal voltage, the inner conductor; A dielectric covering the inner conductor compactly with a center line; And an outer conductor that compactly surrounds the dielectric and has a plurality of radiating slots arranged at equal intervals along the center line, wherein the radiating slot includes a first slot having a predetermined length and the first slot. A plurality of second slots spaced at predetermined intervals and symmetrically inverted in the longitudinal direction are arranged in a zigzag shape in a repeated zigzag shape to radiate electromagnetic waves to the outside.

Preferably, one end or the other end of both side second slots adjacent to the first slot extends a predetermined length in a longitudinal direction, and both side second slots are symmetric about the first slot.

In addition, one end or the other end of both side first slots adjacent to the second slot extends a predetermined length in a longitudinal direction, and both side first slots are symmetric about the second slot.

According to the present invention, the first slot and the second slot are rectangular grooves having a predetermined width in a square shape, and the angle between two sides symmetrical at the center of the rectangular grooves is an obtuse angle.

Preferably, the outer cover for covering the outer conductor; further comprises.

According to the present invention, the wave according to the traveling direction of the electromagnetic wave is a vertically polarized wave.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to the common or dictionary meanings, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, which can be replaced at the time of the present application It should be understood that there may be various equivalents and variations.
Figure 3 is a perspective view schematically showing the structure of a leaky coaxial cable according to a preferred embodiment of the present invention, Figure 4 is a perspective view showing another form of the slot group formed in the leaky coaxial cable of Figure 3, Figure 5 is It is a perspective view which shows another form of the slot group formed in the leaky coaxial cable of FIG.

In an embodiment of the present invention, the electromagnetic wave is an electric wave according to the direction in which the wave proceeds due to the interaction of the electric field and the magnetic field, and the polarization is the progression of the electromagnetic wave. It is a wave along the direction. In addition, the plane by the wave propagation direction and the vector of an electromagnetic field is called a polarization plane.

In this case, a wave in which the polarization plane is perpendicular to the earth is defined as a vertically polarized wave, and a wave in which the polarization plane is horizontal to the earth is defined as a horizontally polarized wave.

The leaky coaxial cable according to the present invention is a structure capable of radiating electromagnetic waves into the atmosphere, the structure of the leaky coaxial cable with reference to FIG.

As shown in FIG. 3, the leakage coaxial cable 100 includes an inner conductor 110, a dielectric 120 that compactly surrounds the inner conductor 110 with a center line, and the dielectric 120 compactly. It consists of an outer conductor 130 to be surrounded, a radiation slots 141, 142, 143, 144 formed in the outer conductor 130 and an outer shell 150 that surrounds the outer conductor 130 compactly. . In this case, the dielectric 120, the outer conductor 130, and the outer shell 150 are sequentially stacked concentrically on the inner conductor 110.

The inner conductor 110 is a conductive wire of a metallic material. As the metal material, a copper tube, an interlocking wire, or a copper aluminum wire may be selectively adopted, and is a transmission line of electromagnetic energy transmitted and received on the leaky coaxial cable 100.

The dielectric 120 is a dielectric layer interposed between the inner conductor 110 and the outer conductor 120 to insulate between the inner and outer conductors 110 and 130 and to prevent loss of electromagnetic wave energy. As the dielectric material, a foamed plastic or a plastic composite insulator is selectively adopted.

The outer conductor 130 is grounded by a ground wire as an electromagnetic shielding layer made of a conductive metal material. As the metal material, a copper tube or a laminated aluminum tape may be selectively adopted.

The outer shell 150 is a corrosion protection layer of a plastic material to prevent corrosion of the outer conductor 130.

In this case, a plurality of radiating slots 141, 142, 143 and 144 are formed in the outer conductor 130 so that a part of the dielectric 120 may be regularly exposed along the center line, and the exposed radiating slots Through 141, 142, 143 and 144, electromagnetic energy can be radiated and absorbed.

Specifically, the plurality of radiating slots 141, 142, 143, 144 are formed in the outer conductor 130 at equal intervals of the same shape along a center line, and the first slot 141 and the second slot. A plurality of slots 142 are arranged along the longitudinal direction of the leaky coaxial cable 100 in a repeated zigzag shape.

The first slot 141 is a rectangular groove having a predetermined width of a square shape having a predetermined length, and an angle θ between two sides symmetrical at the center of the square groove is an obtuse angle approximating the horizontal.

The second slot 142 is spaced apart from the first slot 141 by a predetermined pitch and is symmetrically inverted in the longitudinal direction, and is arranged symmetrically in the longitudinal direction left and right about the first slot 141.

In the embodiment of the present invention, the first and second slots 141 and 142 are arranged along the longitudinal direction of the leaky coaxial cable 100 in the form of discrete zigzag lines spaced at regular equal intervals. Meanwhile, the first and second slots 141 and 142 are slot groups of one cycle in which slots are arranged, and the slot groups are repeatedly arranged along the longitudinal direction of the leaky coaxial cable 100. Radiating slots 141, 142, 143, 144 are formed in the outer conductor 130.

The slot group including the above-described first and second slots can be variously modified, which will be described below with reference to FIGS. 4 and 5.

As shown in FIG. 4, a slot group including modified second slots 142 ′ and 143 symmetric with respect to the first slot 141 may be configured. Specifically, second slots 142 ′ and 143 ′ deformed at predetermined intervals are formed at right and left sides of the first slot 141, and the first slot 141 is formed. The other end symmetrical with one end of the modified second slots 142 ′ and 143 ′ adjacent to is extended in a length direction by a predetermined length. In this case, one end of the modified second slots 142 ′ and 143 ′ adjacent to the first slot 141 may be symmetrically bent in the longitudinal direction to extend a predetermined length.

As another modification, the second slot 142 may be configured as a slot group including the modified first slots 141 'and 144' symmetrically about the second slot 142. In detail, first slots 141 ′ and 144 ′ deformed at predetermined intervals are formed at left and right sides of the second slot 142 in the longitudinal direction, and the second slot 142 is formed. The other end symmetrical to one end of the modified first slots 141 'and 144' adjacent to is extended in a length direction by a predetermined length. In this case, one end of the modified first slots 141 ′ and 144 ′ adjacent to the second slot 142 may be symmetrically bent in the length direction to extend a predetermined length.

When a signal voltage is applied to the input terminal of the leaky coaxial cable having the above-described configuration, the electric field and the electromagnetic wave are radiated through the radiation slot, which will be described below with reference to FIGS. 3 to 5.

Referring to the drawings, current flows through the inner conductor 110 and the outer conductor 130 of the leaky coaxial cable 100 by the signal voltage, and the current flows through the first slot 141 formed in the outer conductor 130 and The current distribution state is changed by the radiation slot including the second slot 142.

At this time, an electromagnetic field is formed around the radiation slot, and an electric field is emitted through the radiation slot. That is, the current energy by the signal voltage is converted into electric field energy and radiated to the atmosphere.

In an embodiment of the present invention, when the slot group including the first and second slots 141 and 142 is regularly arranged, electromagnetic waves having a wave of vertically polarized wave are externally transmitted through the radiation slot. Radiated. In addition, when the modified slot group according to another embodiment of the present invention is arranged regularly, the electromagnetic wave having a wave of the vertical polarization of the extended frequency bandwidth through the radiation slot is radiated to the outside.

In the above-described embodiment, the radiated electromagnetic wave is transmitted to a receiving terminal, that is, a wireless terminal based on vertical polarization including a mobile communication terminal in the form of a wave of vertical polarization. At this time, the wireless terminal can accept the vertical polarization of the leaky coaxial cable without deterioration of sensitivity.

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto and will be described below by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims.

As described above, the present invention can form a variety of slot groups by discontinuous zigzag radial slots in the longitudinal direction of the outer conductor, it is easy to expand the frequency bandwidth for vertical polarization.

In addition, two-way communication with a wireless terminal based on vertical polarization and wideband communication with reduced signal distortion including a specific frequency band are possible in an area where communication with a discrete antenna is not possible.

Claims (9)

In a leaky coaxial cable in which electromagnetic waves are radiated to the outside atmosphere by the application of a signal voltage, Inner conductor; A dielectric covering the inner conductor compactly with a center line; And And an outer conductor that surrounds the dielectric compactly and has a plurality of radial slots arranged at equal intervals along the center line. The radiation slots are arranged in a zigzag shape in which a first slot having a predetermined length having a predetermined length and a second slot symmetrically inverted in a longitudinal direction spaced apart from the first slot at a predetermined interval are arranged along the center line in a plurality of electromagnetic waves. Leakage coaxial cable for vertical polarization, characterized in that to radiate to the outside. The method of claim 1, Leakage coaxial cable for vertical polarization, characterized in that one end or the other end of the two second slots adjacent to the first slot is bent in the longitudinal direction to extend a predetermined length. The method of claim 2, The both side second slots are symmetrical about the first slot, characterized in that the leakage coaxial cable for vertical polarization. The method of claim 1, Leakage coaxial cable for vertical polarization, characterized in that one end or the other end of the first slot on both sides adjacent to the second slot is bent in the longitudinal direction to extend a predetermined length. The method of claim 4, wherein The two first slots are symmetrical about the second slot, characterized in that the leakage coaxial cable for vertical polarization. The method according to any one of claims 1 to 5, The first slot and the second slot is a vertically polarized leakage coaxial cable, characterized in that the rectangular groove having a predetermined width. The method of claim 6, Leak angle coaxial cable for the vertical polarization, characterized in that the angle between the two sides symmetrical from the center of the square groove. The method of claim 1, Leakage coaxial cable for vertical polarization, characterized in that it further comprises; an outer sheath covering the outer conductor. The method of claim 1, Wave according to the traveling direction of the electromagnetic wave (wave) is vertically polarized (Vertically Polarized Wave), characterized in that the vertically polarized leakage coaxial cable.

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