Roll pattern metal outer conductor composite insulation radio frequency coaxial cable for 5G broadband communication

Abstract

The utility model relates to the technical field of communication transmission cables, in particular to a roller pattern metal outer conductor composite insulation radio frequency coaxial cable for 5G broadband communication, which sequentially comprises an inner conductor, an outer conductor, an outer conductor and an outer conductor from inside to outside, the composite insulating layer coats the outer surface of the inner conductor and comprises an inner skin insulating layer, a middle insulating layer and an outer skin insulating layer which are sequentially arranged from inside to outside, and the inner skin insulating layer, the middle insulating layer and the outer skin insulating layer are respectively made of three different thermoplastic polymers; the outer conductor is coated on the outer surface of the outer skin insulating layer; and the sheath layer is made of a high-temperature-resistant plastic material and coats the outer surface of the outer conductor. According to the roller pattern metal outer conductor composite insulation radio frequency coaxial cable for 5G broadband communication, the composite insulation layer is made of three different thermoplastic polymers, the heat resistance of the coaxial cable can be greatly improved, the communication performance is considered, the manufacturing cost is effectively reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of communication transmission cables, and in particular to a composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communications. Background Art

[0002] In current 5G mobile communication base station antenna and feeder systems, the increase in communication frequency has led to an increase in high-frequency signal spatial attenuation. To achieve the widest possible signal coverage, the communication signal power must be continuously enhanced. This also forces the transmission lines to operate at high power for extended periods, causing excessive heating of the RF coaxial cables.

[0003] Conventional RF coaxial cables, on the other hand, use physically foamed polyethylene insulation, typically consisting of three layers. The inner, thin, solid insulation layer near the cable's inner conductor is primarily made of low-density polyethylene (LDPE) or high-density polyethylene (HDPE), incorporating ethylene vinyl acetate (EVA) ester for adhesive properties. The outer, thin, solid insulation layer near the cable's outer conductor is also made of LDPE or HDPE. The thicker, foamed insulation layer in the middle is primarily a mixture of LDPE and HDPE with a nucleating agent, produced using a physical foaming continuous extrusion process. This insulation structure effectively balances attenuation, cost, and production efficiency requirements, but its heat resistance is limited. This is because the LDPE in the cable insulation softens at temperatures of 70°C or even lower. When the cable's feed power is increased, causing the cable's conductor temperature to rise sharply, the air bubbles in the insulation layer in close contact with and adjacent to the conductor collapse, dramatically deteriorating the cable's transmission performance.

[0004] To address the problem of conventional RF coaxial cables being unable to withstand the transmission demands of high-power 5G base station communications, the common approach is to reduce the coaxial cable's attenuation to minimize unnecessary internal heat generation. This results in the use of larger coaxial cables or coaxial cables with smooth outer conductors. However, using larger coaxial cables inevitably increases costs, while using smooth outer conductors reduces the cable's bending performance, hindering installation and routing. Another approach is to use high-temperature fluoroplastic insulation, but since fluoroplastics are much more expensive than conventional polyethylene-based insulation materials, the cost-performance ratio is severely unbalanced. Utility Model Content

[0005] The technical problem to be solved by the present invention is: in order to solve the technical problem of excessive heating of RF coaxial cables in the prior art, the present invention provides a composite insulated RF coaxial cable with a corrugated metal outer conductor for 5G broadband communication. The insulating layer of the present invention adopts a composite insulating layer and a corrugated outer conductor structure, which greatly improves the heat resistance of the coaxial cable and takes into account the communication performance, effectively reduces the manufacturing cost, and improves the production efficiency. It is suitable for the application of the current 5G high-power mobile communication base station antenna feeder system, and has good application prospects and economic benefits.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communication, which includes, from the inside to the outside: an inner conductor, which is a copper tube or copper-clad aluminum wire; a composite insulation layer, which is coated on the outer surface of the inner conductor, including an inner insulation layer, an intermediate insulation layer, and an outer insulation layer arranged from the inside to the outside, and the inner insulation layer, the intermediate insulation layer, and the outer insulation layer are respectively made of three different thermoplastic polymers; an outer conductor, which is coated on the outer surface of the outer insulation layer; and a sheath layer, which is made of high-temperature resistant plastic material and coated on the outer surface of the outer conductor.

[0007] The utility model discloses a composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communication. The composite insulation layer is made of three different thermoplastic polymers, which can greatly improve the heat resistance of the coaxial cable while taking into account the communication performance, effectively reducing the manufacturing cost and improving the production efficiency.

[0008] Furthermore, the inner skin insulation layer adopts a chemical foaming and extruding tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer thin-wall insulation layer.

[0009] Furthermore, the thickness of the endothelial insulation layer is 0.2 mm to 1.2 mm.

[0010] Furthermore, the intermediate insulating layer is formed by physical foaming and extrusion of a blend of high melt strength polypropylene and high density polyethylene.

[0011] Furthermore, the outer insulation layer is a poly(perfluoroethylene propylene) chemical foaming extruded insulation layer.

[0012] Furthermore, the foaming degree of the outer insulation layer is 10% to 40%.

[0013] Furthermore, the outer insulation layer is a chemically foamed and extruded poly(fluoroethylene propylene) (FEP) thin-wall insulation layer.

[0014] Furthermore, the outer insulation layer is maintained between 0.2 mm and 1.4 mm.

[0015] Furthermore, the inner insulating layer, the middle insulating layer and the outer insulating layer are formed by serial extrusion, that is, by continuous processing on the same production line.

[0016] Furthermore, the outer conductor is a welded copper tube or aluminum tube outer conductor and the outer surface is subjected to roller corrugation treatment.

[0017] The beneficial effects of the present utility model are:

[0018] 1. The inner insulation layer is made of chemically foamed and extruded tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) to form a thin-walled insulation layer. After foaming treatment, the insulation layer's heat resistance is improved while reducing dielectric loss.

[0019] 2. The middle insulation layer uses polypropylene (HMS-PP) / HDPE material to replace the traditional LDPE / HDPE mixed insulation layer, which can significantly improve the heat resistance of the middle insulation layer.

[0020] 3. The outer insulation layer is made of a material with heat resistance significantly higher than that of HMW-PP / HDPE mixture but lower than that of PFA, and lower dielectric loss but not as good as that of PFA, based on the actual use environment of RF coaxial cables. While fully considering improving the insulation heat resistance, it also takes into account the need to reduce costs.

[0021] 4. The outer conductor adopts welded copper tube or aluminum tube and roller corrugated the outer surface. The traditional smooth copper or aluminum tube is not used as the outer conductor in order to improve the bending performance of the coaxial cable. The traditional deep corrugation process is not used because although the corrugation process improves the bending performance of the coaxial cable, it reduces the effective outer diameter of the outer conductor of the coaxial cable, increases the attenuation performance of the coaxial cable, and at the same time increases the surface area of ​​the outer conductor, resulting in an increase in the amount of outer conductor used and an increase in manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 It is a front schematic diagram of the entirety of the composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communication in the present invention.

[0024] Figure 2 It is a side schematic diagram of a composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communication in the present invention.

[0025] In the figure: 1. Inner conductor; 2. Composite insulation layer; 21. Inner insulation layer; 22. Intermediate insulation layer; 23. Outer insulation layer; 3. Outer conductor; 4. Sheath layer. DETAILED DESCRIPTION

[0026] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They 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 orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0028] The utility model discloses a composite insulated radio frequency coaxial cable with a roller-corrugated metal outer conductor for 5G broadband communication.

[0029] Reference Figure 1 and Figure 2A composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communications. This patented solution is applicable to the HCTYZ-50-24 cable specified in the YDT 1667 standard. The cable comprises an inner conductor 1, a composite insulation layer 2, an outer conductor 3, and a sheath 4, arranged in this order. The inner conductor 1 can be a smooth copper tube with an outer diameter of 9.00 mm. The composite insulation layer 2 comprises, from inside to outside, an inner insulation layer 21, an intermediate insulation layer 22, and an outer insulation layer 23. The inner insulation layer 21 is a chemically foamed PFA insulation layer with a thickness of 0.2mm to 1.4mm, preferably 0.6mm, and a foaming degree of 23%. The intermediate insulation layer 22 is a physically foamed HMS-PP / HDPE blend with a thickness of 3mm to 9mm, preferably 6.1mm, and a foaming degree of 74%. The outer insulation layer 23 is a chemically foamed FEP insulation layer with a thickness of 0.2mm to 1.4mm, preferably 0.7mm, and a foaming degree of 25%. The cable insulation outer diameter can be 23.8mm. The outer conductor 3 is made of 0.23mm thick copper strip, welded using an argon arc welding roller machine, with a nominal outer diameter of 24.3mm. The jacket layer 4 can be made of a high-temperature resistant plastic material and covers the outer surface of the outer conductor 3.

[0030] Specifically, the primary material for the inner insulation layer 21 is PFA, with the brand TEFLON 340 being an option. The foaming material is ammonium polyphosphate (APP) powder, and the nucleating agent is a mixture of boron nitride (BN) and calcium tetraborate (CTB). Mechanically refined to a median particle size of 1-2 μm, the mixture ratio is 7:3, resulting in a foaming degree of 10%-35% for the inner insulation layer 21. PFA is primarily used for the inner insulation layer 21 because, within the electromagnetic field between the inner and outer conductors 3 of the cable, the surface of the inner conductor 1 has the highest electromagnetic field intensity, the greatest impact on cable attenuation, and the highest temperature. Therefore, a material with high temperature resistance is required. PFA has a melting point of 310°C, offering advantages such as high temperature resistance, low dielectric loss, and good adhesion to metals. In addition, the use of a mixture of boron nitride (BN) and calcium tetraborate (CTB) as a nucleating agent can make PFA foam more fully, with a foaming degree of up to 10% to 35%, thereby further reducing the insulating dielectric loss of the inner insulation layer 21, improving the attenuation performance of the cable, and reducing ineffective heat energy consumption.

[0031] Specifically, the middle insulating layer 22 is a physically foamed HMS-PP / HDPE blend. HMS-PP can be HMS20Z from Sinopec, and HDPE is not limited. The HMS-PP / HDPE blend ratio is 30% wt:70% wt. The physical foaming gas can be liquid CO2 or N2. The insulation layer is made of a HMS-PP / HDPE blend. Traditional insulation layers generally use LDPE. Since LDPE has average heat resistance, although the middle insulating layer 22 does not directly contact the conductor, it still affects the overall heat resistance of the cable. To improve the heat resistance of the overall insulation, polypropylene (HMS-PP) is used instead of the original LDPE, which can significantly improve the heat resistance of the middle insulating layer 22.

[0032] Specifically, the outer insulation layer 23 is primarily made of FEP, and Zhejiang Juhua cable insulation grade FEP can be used. The foaming material is mechanically refined hydrated magnesium silicate with a median particle size of (1-2) μm. Tube extrusion is used, and the extrusion draw ratio (DDR) is controlled at 10. FEP is used for the outer insulation layer 23 because the outer insulation layer is in close contact with the inner surface of the outer conductor 3 and is affected by the heat generated by the outer conductor 3 during cable use. However, since the electromagnetic field intensity on the inner surface of the outer conductor 3 is lower than that on the outer surface of the cable's inner conductor 1, and the outer conductor 3 generally has a lower DC resistance than the inner conductor 1, dissipating heat more easily, the outer conductor 3 has less impact on cable attenuation and conductor heat rise than the inner conductor 1. Therefore, the outer insulation layer 23 is made of fluorinated ethylene propylene (FEP), which has a heat resistance significantly higher than that of the HMW-PP / HDPE blend but lower than that of PFA, a lower dielectric loss but not as good as that of PFA, and a lower cost. The fluorinated ethylene propylene (FEP) material is manufactured using a chemical foaming extrusion process.

[0033] Specifically, the outer conductor 3 can be formed from a 0.23mm thick copper strip welded using an argon arc welding roller mill, resulting in a nominal outer diameter of 24.3mm. The outer conductor 3 is constructed from a welded copper or aluminum tube with a roller mill finish, rather than a conventional smooth copper or aluminum tube, to improve the coaxial cable's bending performance. The reason for not using the conventional deep corrugation process is that, while corrugation improves the coaxial cable's bending performance, it also reduces the effective outer diameter of the outer conductor 3, thereby increasing the cable's attenuation performance. This also increases the outer conductor 3's surface area, leading to an increase in the outer conductor 3's usage and manufacturing costs.

[0034] Compared with the standard coaxial cable with model HCTYZ-50-24 in the YDT 1667 standard, the peak power of the standard coaxial cable with model HCTYZ-50-24 is 80kW, while the peak power of the structural cable of the present application is increased to 100kW, an increase of about 20%.

[0035] Working Principle: The inner insulation layer uses chemically foamed extruded tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) to form a thin-walled insulation layer. After the foaming process, the insulation layer's heat resistance is improved while reducing the dielectric loss. The middle insulation layer 22 uses polypropylene HMS-PP / HDPE material to replace the traditional LDPE / HDPE mixed insulation layer, which can significantly improve the heat resistance of the middle insulation layer 22. The outer insulation layer is based on the actual use environment of the RF coaxial cable. The heat resistance is significantly higher than that of the HMW-PP / HDPE mixture but not as good as PFA, and the dielectric loss is lower but not as good as PFA. While fully considering the improvement of the insulation heat resistance, the need to reduce costs is also taken into account.

[0036] The outer conductor 3 is made of a welded copper tube or aluminum tube and the outer surface is roller-corrugated. The traditional smooth copper or aluminum tube is not used as the outer conductor 3 in order to improve the bending performance of the coaxial cable; the traditional deep corrugation process is not used because although the corrugation process improves the bending performance of the coaxial cable, the process reduces the effective outer diameter of the outer conductor 3 of the coaxial cable, increases the attenuation performance of the coaxial cable, and at the same time increases the surface area of ​​the outer conductor 3, resulting in an increase in the amount of outer conductor 3 and an increase in manufacturing costs.

[0037] Based on the above-mentioned ideal embodiment of the present invention, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the technical scope of the present invention. The technical scope of the present invention is not limited to the content of the specification, but must be determined according to the scope of the claims.

Claims

1. A composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communication, characterized in that: From inside to outside, it includes: The inner conductor (1) is made of a copper tube or a copper-clad aluminum wire; A composite insulating layer (2) is coated on the outer surface of the inner conductor (1), comprising an inner skin insulating layer (21), an intermediate insulating layer (22), and an outer skin insulating layer (23) arranged in sequence from the inside to the outside, wherein the inner skin insulating layer (21), the intermediate insulating layer (22), and the outer skin insulating layer (23) are respectively made of three different thermoplastic polymers; An outer conductor (3) coated on the outer surface of the outer insulation layer (23); A sheath layer (4) is made of a high-temperature resistant plastic material and is coated on the outer surface of the outer conductor (3); The inner skin insulation layer (21) is a thin-walled insulation layer of a chemically foamed and extruded tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer; The intermediate insulating layer (22) is formed by physical foaming and extrusion of a blend of high melt strength polypropylene and high density polyethylene; The outer skin insulation layer (23) is a polyperfluoroethylene propylene chemical foaming extruded insulation layer.

2. The 5G broadband communication composite insulated radio frequency coaxial cable with a rolled metal outer conductor according to claim 1, characterized in that: The thickness of the inner skin insulation layer (21) is 0.2 mm to 1.2 mm.

3. The 5G broadband communication composite insulated radio frequency coaxial cable with a rolled metal outer conductor as claimed in claim 1, characterized in that: The foaming degree of the outer skin insulating layer (23) is 10% to 40%.

4. The composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communication according to claim 3, characterized in that: The outer skin insulation layer (23) is a chemically foamed and extruded polyperfluoroethylene propylene (FEP) thin-wall insulation layer.

5. The composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communication according to claim 4, characterized in that: The outer insulation layer (23) is maintained between 0.2 mm and 1.4 mm.

6. The composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communication according to claim 1, characterized in that: The inner insulating layer (21), the middle insulating layer (22) and the outer insulating layer (23) are formed by serial extrusion, that is, they are continuously processed on the same production line.

7. The composite insulated radio frequency coaxial cable with a corrugated metal outer conductor for 5G broadband communication according to claim 1, characterized in that: The outer conductor (3) is a welded copper tube or aluminum tube outer conductor (3) and the outer surface is subjected to roller processing.

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