Leaky coaxial cable for 5G signal transmission

Abstract

The present invention provides a coaxial leaky cable for 5G signal transmission, including a leaky cable conductor with a hollow structure inside for transmitting signals, a polyolefin insulation layer and an outer conductor sequentially coated on the outside of the leaky cable conductor, and a plurality of slots for improving signal transmission are provided on the outer periphery of the outer conductor by laser grooving in the axial and / or radial directions at preset intervals. Since a graphene coating is applied to the outside of the inner conductor and the inside of the outer conductor, the conductor loss of the product is reduced, so that the cable can transmit a higher frequency; three-layer co-extrusion physical foaming technology is directly used on the inner conductor and the outer conductor to reduce the insulation equivalent dielectric constant. The use of laser grooving can achieve denser and more precise grooving. The cable of the present invention has excellent electrical and optical properties and better thermal conductivity, and has higher mechanical strength and is economical and practical.

Description

Technical Field

[0001] The present invention relates to the technical field of communication cables, and in particular to a coaxial leaky cable for 5G signal transmission. Background Art

[0002] Leaky coaxial cable is also called leaky coaxial cable, which consists of three parts: inner conductor, insulating medium and outer conductor with periodic slots. Electromagnetic waves are transmitted longitudinally in the leaky cable and radiated to the outside through the slots; the external electromagnetic field can also be sensed inside the leaky cable through the slots and transmitted to the receiving end. Leaky coaxial cable is suitable for various existing wireless communication systems, and its application scenarios include subways, railway tunnels and highway tunnels where wireless transmission is limited.

[0003] The current RF coaxial cable mainly uses foamed polyethylene insulation and a longitudinally wrapped copper tape outer conductor to form a radiating leaky coaxial cable with an operating frequency of 70MHz to 2620MHz. Due to the unreasonable structural design, the existing leaky cable cannot be used for effective transmission in the 5G frequency band.

[0004] Therefore, the prior art has defects and needs to be improved. Summary of the invention

[0005] The main purpose of the present invention is to propose a coaxial leaky cable for 5G signal transmission with reduced conductor loss, better transmission effect and better radiation of electromagnetic waves.

[0006] The technical solution proposed by the present invention for the above-mentioned technical problem is as follows: a coaxial leaky cable for 5G signal transmission, comprising a leaky cable conductor with a hollow structure inside for transmitting signals, the leaky cable conductor comprising an inner conductor and a first graphene coating coated on the outer periphery of the inner conductor with a first preset thickness, an inner skin layer, a foam layer, an outer skin layer, an outer conductor and a sheath layer sequentially coated on the outside of the first graphene coating; a second graphene coating is coated on the inner circumference of the outer conductor with a second preset thickness, and a plurality of slots for improving signal transmission are opened on the outer periphery of the outer conductor by laser grooving technology along the axial direction at preset intervals; a sheath identification portion for identifying the slot position of the outer conductor is arranged on the outer side of the sheath layer corresponding to the opposite side of the slot, the preset distance between each of the slots along the axial direction is 5 mm~20 mm, and the inclination angle of each of the slots is 40°~50°; the shape of the sheath identification portion includes triangle, square or arc.

[0007] By adopting the above technical solution, the outer surface of the inner conductor and the inner surface of the outer conductor are coated with graphene coating, which reduces the conductor loss of the product and enables the cable to transmit higher frequencies; the inner and outer conductors are directly subjected to three-layer co-extrusion physical foaming technology, and high-purity CO2 is injected during insulation extrusion to form uniform pores and reduce the equivalent dielectric constant of the insulation. The laser grooving method can achieve denser and more precise grooving.

[0008] Among them, the inner conductor is a metal tube, and the outer diameter of the metal tube is 5.0mm~13.5mm; the first preset thickness and the second preset thickness range are 0.1 micron~0.2 micron; a plurality of slots are radially opened on the outer circumference of the outer conductor, and each slot is evenly distributed at 120 degrees, and the sheath identification part is arranged on the opposite side of each slot outside the sheath layer.

[0009] By adopting the above technical solution, a graphene coating with a certain thickness is coated on the outside of the inner conductor and the inside of the outer conductor. The double-layer graphene coating makes the cable have excellent electrical and optical properties and better thermal conductivity, and higher mechanical strength. A sheath identification part is provided on the opposite side of each slot outside the sheath layer, through which the internal slot position can be clearly known, which is very practical.

[0010] The technical solution provided by the embodiment of the present invention has the following beneficial effects: due to the use of a double-layer graphene coating, the conductor loss is reduced, and the 5G signal with a frequency of 3.5~3.8GHz can be effectively transmitted. Secondly, by using CO2 gas for foaming, the pores are more uniform, and the foaming degree can reach more than 75%. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of a coaxial leaky cable provided in Embodiment 1 of the present invention.

[0012] Figure 2 It is a structural schematic diagram of another embodiment of the coaxial leaky cable provided by the present invention.

[0013] Figure 3 It is a schematic structural diagram of an outer conductor provided by the present invention having slots provided along the axial direction.

[0014] Figure 4 It is a structural schematic diagram of the angle and distance between each slot hole provided in the axial direction of the outer conductor provided by the present invention.

[0015] Figure 5 It is a schematic structural diagram of the sheath identification portion of the sheath layer provided by the present invention along the axial direction.

[0016] Figure 6It is a schematic structural diagram of a sheath identification portion provided outside the sheath layer and slots provided in the radial direction of the outer conductor provided by the present invention. DETAILED DESCRIPTION

[0017] In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Typical embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0018] It should be noted that the terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only. Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0019] Terms including ordinal numbers such as "first", "second" etc. used in this specification may be used to describe various constituent elements, but these constituent elements are not limited by these terms. The purpose of using these terms is only to distinguish one constituent element from other constituent elements. For example, without departing from the scope of the present invention, the first constituent element may be named as the second constituent element, and similarly, the second constituent element may also be named as the first constituent element. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0020] The general idea of ​​the present invention is: laser grooving technology is used on the outer circumference of the outer conductor to periodically open multiple slots at preset intervals in the axial direction, and the slots are inclined at a certain angle. Three-layer co-extrusion physical foaming technology is directly used on the inner conductor and the outer conductor. High-purity CO2 is injected during insulation extrusion to form uniform bubbles, reduce the insulation equivalent dielectric constant, reduce conductor loss, improve transmission effect, and better radiate electromagnetic waves.

[0021] In order to better understand the above-mentioned technical scheme, the above-mentioned technical scheme will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical scheme of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0022] refer to Figure 1In a specific embodiment of the present invention, the coaxial leaky cable includes a leaky cable conductor 100 with a hollow structure inside for transmitting signals, a polyolefin insulation layer 200 and an outer conductor 300 sequentially coated on the outside of the leaky cable conductor 100, and a plurality of slots 301 for improving signal transmission are provided on the outer circumference of the outer conductor 300 by laser grooving along the axial direction and / or radial direction at preset intervals. The outermost layer of the coaxial leaky cable also includes a sheath layer 400, and the sheath layer 400 is coated on the outside of the outer conductor 300, and a sheath identification portion 401 for identifying the slot position of the outer conductor 300 is provided on the opposite side of the sheath layer 400 corresponding to the slot 301. Further in combination with the attached Figure 2 As shown, the leaky cable conductor 100 includes an inner conductor 101 and a first graphene coating 102 coated on the outer periphery of the inner conductor 101 with a first preset thickness. The first preset thickness is between 0.2 microns and 2 microns, or thinner, and the first graphene coating 102 makes the cable more conductive and has higher mechanical strength. The polyolefin insulation layer 200 includes an inner layer 201, a foam layer 202 and an outer layer 203 extruded at one time by an extruder, and the inner layer 201, the foam layer 202 and the outer layer 203 are sequentially coated on the outer periphery of the first graphene coating 102. A second graphene coating 302 is also provided between the outer conductor 300 and the outer skin layer 203. The second graphene coating 302 is coated on the inner circumference of the outer conductor 300 with a second preset thickness, and the second preset thickness is between 0.2 microns and 2 microns. By coating the graphene coating on the outside of the inner conductor and the inside of the outer conductor, and coating different thicknesses of the graphene coating at different positions, such as the first graphene coating having a coating thickness of 2 microns and the second graphene coating having a coating thickness of 0.2-0.5 microns, the technical effect of minimizing the conductor loss of the product and enabling the cable to transmit a higher frequency can be achieved. The three-layer co-extrusion physical foaming technology is directly adopted in the inner conductor and the outer conductor. By injecting high-purity CO2 during insulation extrusion, uniform pores can be formed in the foam layer 202, thereby reducing the insulation equivalent dielectric constant. The polyolefin insulation layer of the present invention is usually a polyethylene material, and the foaming method can be a physical foaming method. The physical foaming injection gas is CO2, so that the foaming degree of the foam layer 202 is 70% to 90%.

[0023] Further, see Appendix Figure 3 and attached Figure 4 As shown, there are periodic slots on the outer conductor 300, and one embodiment of the periodic slots is to be opened along the axial direction of the outer circumference of the outer conductor 300, wherein, see the attached Figure 4The preset distance p between each slot 301 is 5 mm to 20 mm, and the inclination angle a of each slot 301 is 40° to 50°. The present invention adopts laser slotting technology, and the optimal distance of the slotting period p can be controlled at 8 mm, and the angle between the slotting angle and the horizontal axis of the cable is 45°, which is the optimal angle. The present invention is provided with periodic slots along the axial direction on the outer conductor, which can achieve more dense and more precise slotting and ensure better transmission signals.

[0024] See attached Figure 5 As shown, the shape of the sheath identification part 401 provided on the outer periphery of the sheath layer 400 includes a triangle, a square or an arc. The sheath identification part is used to identify the slot position of the outer conductor, and is usually provided on the opposite side of the slot. Its shape and color are not limited, and the color may be consistent with the sheath color or inconsistent with the sheath color. As long as it can provide a striking reminder of the internal slot position, it improves the practicality of the user.

[0025] Furthermore, the inner conductor of the present invention can be a smooth copper tube or a corrugated copper tube, with a nominal outer diameter of 5.0mm~13.5mm; the first and second graphene coatings: the thickness is between 0.2-2 microns, generally 0.0025mm or thinner. Inner cortex: thickness 0.1~0.2mm; foaming layer: foaming degree 70%~90%; outer cortex: 0.1~0.2mm; the outer conductor is a copper strip, with a thickness of 0.1mm and an outer diameter of 20~50mm; the sheath layer is made of polyolefin, with an outer diameter of 23~55mm and a thickness of 1.4~2.0mm. The design of the above technical solution solves the technical problems of high conductor loss rate, low cable transmission frequency, and high insulation equivalent dielectric constant in the prior art.

[0026] Based on the same concept, the present invention also provides another implementation scheme, see the attached Figure 6As shown, the coaxial leaky cable includes a leaky cable conductor 100 with a hollow structure inside and used for transmitting signals. The leaky cable conductor 100 includes an inner conductor 101 and a first graphene coating 102 coated on the outer periphery of the inner conductor 101 with a first preset thickness, an inner skin layer 201, a foam layer 202, an outer skin layer 203, an outer conductor 300 and a sheath layer 400 sequentially coated on the outer periphery of the first graphene coating 102; a second graphene coating 302 is coated on the inner periphery of the outer conductor 300 with a second preset thickness. , multiple slots 301 for improving signal transmission are provided on the outer circumference of the outer conductor 300 at preset intervals in the axial direction and radial direction; a sheath identification portion 401 for identifying the slot position of the outer conductor 300 is provided on the outer side of the sheath layer 400 corresponding to the slot 301, and the preset distance between each slot 301 in the axial direction is 8mm, and the inclination angle of each slot 301 is 45°; the shape of the sheath identification portion 401 can be triangular, square or arc-shaped, and the color is not limited. The first preset thickness and the second preset thickness range from 0.1 micron to 0.2 micron; another embodiment of the present invention is that three slots 301 are also provided on the outer circumference of the outer conductor 300 in the radial direction, and each radially slotted slot 301 is also provided in the attached Figure 4 The axial direction of the cable is opened, and each slot 301 opened in the radial direction is evenly distributed at 120 degrees, and three sheath identification parts 401 are arranged on the opposite side of each slot 301 outside the sheath layer 400, which penetrate the outer circumference of the sheath layer 400 axially, forming a triangular distribution on the outer circumference. With such a design, a cable capable of transmitting higher frequencies and faster transmission speeds can be achieved, and the triangular distribution outside the sheath layer 400 also strengthens the strength of the leaky cable, prolongs its service life, and reduces the friction loss problem on the ground.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A coaxial leaky cable for 5G signal transmission, characterized in that: The invention comprises a leaky cable conductor (100) having a hollow structure inside and used for transmitting signals, wherein the leaky cable conductor (100) comprises an inner conductor (101) and a first graphene coating (102) coated on the outer periphery of the inner conductor (101) with a first preset thickness, an inner skin layer (201), a foam layer (202), an outer skin layer (203), an outer conductor (300) and a sheath layer (400) sequentially coated on the outer periphery of the first graphene coating (102); a second graphene coating (302) is coated on the inner periphery of the outer conductor (300) with a second preset thickness, and the first preset thickness and the second preset thickness are in the range of 0.1 micrometer to 0.2 micrometer; a plurality of slots (301) for improving signal transmission are formed on the outer periphery of the outer conductor (300) by laser in an axial direction at preset intervals, and a plurality of slots (301) are also formed on the outer periphery of the outer conductor (300) by laser in a radial direction, and the slots (301) are evenly distributed at 120 degrees; A sheath identification portion (401) for identifying a slotted position of the outer conductor (300) is provided on the outside of the sheath layer (400) at the opposite side of each slot hole (301); a preset distance between each slot hole (301) in the axial direction is 5 mm to 20 mm; and an inclination angle of each slot hole (301) is 40° to 50°; the shape of the sheath identification portion (401) includes a triangle, a square or an arc.

2. The coaxial leaky cable according to claim 1, characterized in that: The inner conductor (101) is a metal tube, and the outer diameter of the metal tube is 5.0 mm to 13.5 mm.

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