Leaky coaxial cable

Abstract

The utility model discloses a leaky coaxial cable, which is provided with an inner conductor, an insulating layer, an outer conductor and an outer protective layer in sequence from inside to outside, the outer conductor is groove-shaped, the design of upper and lower parts is adopted, the upper and lower parts of the groove-shaped are moved up and down and / or left and right according to radiation intensity and radiation area, and under the condition of certain signal input, the leaky coaxial cable can be used as a leaky coaxial cable. By increasing the groove types and changing the positions of the groove types, increasing the radiation area of the cable and / or increasing the radiation signal intensity and enhancing the signal coverage of the leaky coaxial cable, the radiation intensity and / or the radiation area of signals are / is increased, and the leaky coaxial cable is used for transmitting signals and completing signal reception and coverage.

Description

Technical Field

[0001] The utility model belongs to the technical field of communication cables, and particularly relates to a leaky coaxial cable. Background Art

[0002] Leaky coaxial cables are generally used for laying in tunnels or indoor space tunnels and buildings. During the longitudinal propagation of signals along the cable, part of the signal completes the information exchange between the internal signal and the external signal along the slotted part of the cable outer conductor, and has achieved radial signal coverage of the cable in the signal laying area. Due to the rapid development of wireless transmission this year, the frequency band has been continuously expanded and the requirements have been continuously improved. Leaky coaxial cables serve as the transmission channels of wireless signals. The design of leaky cables is required to continuously enhance the ability of radiating signals and / or increase the radiation area while meeting the width usage.

[0003] The invention with announcement number CN114421168A discloses a leaky coaxial cable, which is formed by arranging a double row of slot groups on the outer conductor along the axial direction of the cable, and the center of the double row of slot groups coincides with the central axis of the cable, each row of slot groups includes a plurality of slot arrays periodically arranged along the axial direction of the outer conductor, the pitch P of each slot array is the same and is selected according to the frequency of use, the gain G generated by the double row of slot groups meets the requirements, and the coupling loss can be reduced. At the same time, the radiation direction is controlled by adjusting the slot angle α, so that the energy is concentrated in the receiving direction to increase the effective field strength, reduce the waste of invalid energy, and increase the use distance of the cable. However, this slotting method cannot increase the radiation efficiency and meet the high specifications of the frequency band width. Utility Model Content

[0004] The purpose of the utility model is to provide a leaky coaxial cable to address the deficiencies of the prior art, increase the radiation area of ​​the cable and / or increase the radiation signal strength, and enhance the signal coverage of the leaky coaxial cable.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0006] A leaky coaxial cable comprises an inner conductor, an insulating layer, an outer conductor and an outer sheath arranged in sequence from the inside to the outside, the outer conductor is provided with periodically arranged slots, and the slots in one period are divided into upper and lower parts and move up and down and / or horizontally, the center line spacing of the upper and lower parts is denoted as d, and the value range is 0<d≤10,

[0007] The horizontal movement distance of the upper and lower parts in one cycle is recorded as m, and the value range is 0≤m≤P / 2, where P is the slot design pitch.

[0008] The upper and lower parts of the groove are identical repeating structures, or staggered structures within a period.

[0009] The distance from the highest point to the lowest point of the groove is recorded as D, and D=(0.26~3.5)×D 1 , D 1 is the cable diameter.

[0010] The inner conductor is made of 0.01-0.35 mm copper strip welded corrugated, 0.1-0.5 mm smooth copper tube, copper clad aluminum, copper clad steel or copper alloy metal.

[0011] The insulating layer is made of physically foamed polyethylene, chemically foamed polyethylene, physically foamed polytetrafluoroethylene, and physically foamed polypropylene, with a relative dielectric constant of 1 to 2.4. The insulating layer is attached to the inner conductor, and the thickness of the insulating layer is 2-20 mm.

[0012] The outer conductor is made of 0.005-0.15mm slotted metal material, and the copper strip is longitudinally wrapped outside the cable insulation layer through a longitudinal wrapping mold. The slot shape is input into the electrical equipment or the mold is made, and the outer conductor is slotted with the copper strip. The slot shape is a straight slot, an elliptical slot, a U-shaped slot, an L-shaped slot or a combined slot.

[0013] The outer sheath has a thickness of 0.2-3.5 mm and is made of flame-retardant or non-flame-retardant polyolefin, and is covered on the outer conductor of the cable using extrusion or wrapping equipment.

[0014] The beneficial effects of the utility model are:

[0015] (1) The utility model discloses a leaky coaxial cable, which is provided with an inner conductor, an insulating layer, an outer conductor and an outer sheath in sequence from the inside to the outside. The outer conductor is slotted and designed in two parts, and the upper and lower parts of the slot are moved up and down and / or left and right according to the radiation intensity and the radiation area. Under the condition of a certain signal input, the radiation area of ​​the cable and / or the radiation signal strength are increased by adding slots and changing the position of the slots, thereby strengthening the signal coverage of the leaky coaxial cable, thereby increasing the radiation intensity and / or radiation area of ​​the signal, and transmitting the signal to complete the signal reception and coverage.

[0016] (2) The cable structure includes an inner conductor, an insulator, an outer conductor, and an outer sheath. This structure is easy to produce and operate, has excellent compression and tensile properties, and can guarantee a service life of at least 15 years. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the cross section of the cable of the utility model;

[0018] Figure 2 This is a schematic diagram of the groove structure of the utility model Figure 1 ;

[0019] Figure 3 This is a schematic diagram of the groove structure of the utility model Figure 2 ;

[0020] Figure 4 This is a schematic diagram of the groove structure of the utility model Figure 3 ;

[0021] Figure 5 This is a schematic diagram of the groove structure of the utility model Figure 4 ;

[0022] Figure 6 This is a schematic diagram of the groove structure of the utility model Figure 5 ;

[0023] Figure 7 This is a schematic diagram of the radiation intensity of a single-layer slot type of the utility model;

[0024] Figure 8 This is a schematic diagram of the radiation intensity of the slots in the upper and lower parts of the utility model;

[0025] Fig. 9 This is a process flow chart of the utility model. DETAILED DESCRIPTION

[0026] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0027] The utility model provides a leaky coaxial cable, such as Figures 1 to 9 shown.

[0028] A leaky coaxial cable comprises an inner conductor 1, an insulating layer 2, an outer conductor 3 and an outer sheath 4 which are arranged in sequence from the inside to the outside. The outer conductor 3 is provided with periodically arranged slots 6, and the slots in one period are divided into upper and lower parts and move up and down and / or horizontally. The spacing between the center lines of the upper and lower parts of the slots is recorded as d, and the value range is 0<d≤10. The horizontal movement distance of the upper and lower parts in one period is recorded as m, and the value range is 0≤m≤P / 2, where P is the slot design pitch. The distance from the highest point to the lowest point of the slot is recorded as D, and D=(0.26~3.5)×D 1 , D 1 is the cable diameter. The slot shape of the slot 6 is a straight slot, an elliptical slot, a U-shaped slot, an L-shaped slot or a combination slot, such as a combination of a circular and a straight slot. The inner conductor is made of copper strip welding corrugation, a smooth copper tube, copper-clad aluminum, copper-clad steel or copper alloy metal; the insulation layer is made of physical foamed polyethylene, chemical foamed polyethylene, physical foamed polytetrafluoroethylene, physical foamed polypropylene or physical foamed mixed gas, with a relative dielectric constant of 1 to 2.4; the outer conductor is made of a slotted metal strip of 0.005 to 0.15 mm, and a series of slots are opened on the metal strip according to the frequency band used, such as Figure 1-7As shown, by designing production equipment and wrapping it longitudinally on the insulator, the cable has the ability to transmit signals; the outer sheath is made of flame retardant or non-flame retardant polyolefin. In this embodiment, flame retardant polyolefin is used, which can have flame retardant and fireproof functions.

[0029] The upper and lower parts of the slot can be identical repeating structures, or staggered structures within a period; the specific structure can be determined according to the radiation efficiency within the frequency band of use:

[0030] η=(A / B)*100%,

[0031] In the formula, A is the radiation power in one cycle, and B is the input power in one cycle;

[0032] If the input power B is 120dBμV in one cycle and the radiation power A is 40dB in one cycle, the radiation efficiency η=(40 / 120)*100%=33.3%. For example, at the frequency of 3400MHz, the radiation power of the single-layer slot is 39.8dB, and the radiation power of the upper and lower distributed slot is 55.2dB, and the radiation efficiency increases by 12.8%. The single-layer radiation power of the slot using the angle is 42dB, and the radiation power of the upper and lower distributed slot is 55dB, and the radiation intensity increases by 10.8%.

[0033] A method for manufacturing a leaky coaxial cable comprises the following steps:

[0034] (1) When the inner conductor is a corrugated copper tube, the copper strip is installed on a tape unwinder, the copper strip is cut into the use width by a cutter, the copper tube is welded into a copper tube by argon arc welding, and the corrugated copper tube is produced by a corrugating machine or purchased metal materials are used;

[0035] (2) The foamed material is fed into the extrusion equipment, the inner conductor is passed through the extruder head, and the melted and mixed foamed material is evenly coated on the inner conductor to form an insulating layer. The concentricity of the insulating layer and the inner conductor is not less than 93%;

[0036] (3) Input the designed slot shape into the slot milling equipment, which is recognized by the software in the equipment. The laser slot milling equipment cuts the metal strip on the 0.005-0.15mm metal strip according to the upper and lower structures and the front and back order of the designed graphics according to the graphics recognized by the equipment, or produces a cutter according to the designed graphics, installs it on the mechanical punching machine, adjusts the pitch, and punches and mills the metal strip to form a milled metal strip;

[0037] (4) The milled metal strip is passed through a longitudinal wrapping die and longitudinally wrapped outside the insulating layer to form an outer conductor;

[0038] (5) Through extrusion equipment or wrapping equipment, the coated outer conductor is evenly covered with an outer sheath with a thickness of 0.2-3.5mm to form a finished cable.

[0039] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] In order to better understand the present utility model patent, the following examples are given in conjunction with the accompanying drawings to further illustrate the technical solution of this implementation.

[0041] Reference Figure 1 The leaky coaxial cable structure is composed of an inner conductor 1, an insulating layer 2, an outer conductor 3 and an outer sheath 4 from the inside to the outside, and a slot 6 is provided on the outer conductor; the inner conductor 1 is coated with an insulating layer 2, the slotted outer conductor 3 is tightly wrapped outside the insulating layer 2, the slotted outer conductor 3 is extruded with an outer sheath 4, and a marking line 5 is provided outside the outer sheath 4.

[0042] Reference Figure 2 to Figure 6 As shown, the distance between the highest point and the lowest point of the slot is D, the distance between the center lines of the upper and lower slots is d, and the longitudinal spacing between the upper and lower slots is m. The slot is moved up, down, left, and right according to the radiation intensity, that is, the frequency band requirements, and D=(0.18~3.14)×D 1 , 0≤m≤P / 2,0<d≤10, adjust the radiation intensity, that is, the radiation area, D 1 Cable diameter Figure 1 shown.

[0043] The signal is transmitted in the signal transmission channel composed of the inner conductor and the outer conductor. Some slots are opened on the outer conductor according to certain rules. During the longitudinal transmission of the signal in the cable, the signal is coupled from the slot of the outer conductor to the external space, and the signal in the external space is coupled to the inside of the cable through the slot, so as to achieve mutual transmission of signals through the leaky coaxial cable.

[0044] The outer conductor and the inner conductor form a signal transmission channel. The outer conductor serves to shield external interference signals. The platform and the terminal transmit information using a specific frequency through the slots on the outer conductor to complete signal reception and coverage.

[0045] The leaky coaxial cable and its manufacturing method are characterized by sequentially arranging an inner conductor, an insulating layer, an outer conductor and an outer sheath from the inside to the outside. The outer conductor uses a slotted metal strip and is designed with an upper and lower part. The upper and lower parts of the slot are moved up and down and / or left and right according to the radiation intensity, that is, the radiation area. Under the condition of a certain signal input, the radiation intensity, that is, the radiation efficiency and the radiation range of the signal can be increased to increase the radiation intensity and / or radiation area of ​​the signal, which is used to transmit the signal and complete signal reception and coverage.

[0046] If the words "first", "second" and so on are used in this patent to limit components, those skilled in the art should know that the use of "first" and "second" is only for the convenience of describing the utility model and simplifying the description, and the above words have no special meaning.

[0047] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. The utility model may have various changes and improvements without departing from the spirit and scope of the utility model. These changes and improvements fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

[0048] In the description of the present invention, it is necessary to understand that the terms "front", "rear", "left", "right", "center", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the protection content of the present invention.

Claims

1. A leaky coaxial cable, characterized in that: It includes an inner conductor, an insulating layer, an outer conductor and an outer sheath arranged in sequence from the inside to the outside. The outer conductor is provided with periodically arranged slots, and the slots in one period are divided into upper and lower parts and move up and down and / or horizontally. The center line spacing of the upper and lower parts is recorded as d, and the value range is 0<d≤10. The horizontal movement distance of the upper and lower parts in one cycle is recorded as m, and the value range is 0≤m≤P / 2, where P is the slot design pitch.

2. A leaky coaxial cable according to claim 1, characterized in that: The upper and lower parts of the groove are identical repeating structures, or staggered structures within a period.

3. A leaky coaxial cable according to claim 1, characterized in that: The distance from the highest point to the lowest point of the slot is recorded as D, and D=(0.26~3.5)×D1, where D1 is the cable diameter.

4. A leaky coaxial cable according to any one of claims 1 to 3, characterized in that: The inner conductor is made of copper strip welded corrugation, smooth copper tube, copper clad aluminum, copper clad steel or copper alloy metal.

5. A leaky coaxial cable according to claim 4, characterized in that: The insulating layer is made of physically foamed polyethylene, chemically foamed polyethylene, physically foamed polytetrafluoroethylene, and physically foamed polypropylene, and the relative dielectric constant is between 1 and 2.

4.

6. A leaky coaxial cable according to claim 4, characterized in that: The slot opening shape is a straight slot, an elliptical slot, a U-shaped slot, an L-shaped slot or a combined slot.

7. A leaky coaxial cable according to claim 4, characterized in that: The outer sheath has a thickness of 0.2-3.5 mm and is made of flame-retardant or non-flame-retardant polyolefin.

8. A leaky coaxial cable according to claim 4, characterized in that: The outer conductor is made of a slotted metal strip with a thickness of 0.005-0.15 mm.

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