5g radio frequency coaxial cable and method of making same

Abstract

The present application relates to the technical field of cable, especially to a 5G radio frequency coaxial cable and a preparation method thereof, which comprises, from inside to outside, an inner conductor, an inner skin layer, a foamed insulation layer, an outer skin layer, an outer conductor and a protective sleeve layer; the inner conductor is a spiral corrugated inner conductor, the outer conductor is a spiral corrugated outer conductor, and the spiral direction of the inner conductor is the same as that of the outer conductor; the inner surface and the outer surface of the inner skin layer are both spiral, and the spiral of the inner surface of the inner skin layer and the spiral of the inner conductor are matched with each other after the inner skin layer is in close contact with the inner conductor; the inner surface of the protective sleeve layer is spiral, and the spiral of the inner surface of the protective sleeve layer and the spiral of the outer conductor are matched with each other after the protective sleeve layer is in close contact with the outer conductor. The present application provides a 5G radio frequency coaxial cable, which has good softness, high bending performance, is suitable for use in complex environments such as narrow space, tower top and more right-angle turns, and has good electrical performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cable, in particular to a 5G radio frequency coaxial cable and a preparation method thereof. BACKGROUND

[0002] The development of mobile communication is becoming more and more rapid, and the radio frequency coaxial cable used by mobile communication base station is developing towards multiple scenes, low cost, high performance and the like. The radio frequency coaxial cable used by mobile communication base station in the prior art is composed of four parts of an inner conductor, an insulating layer, an outer conductor and a sheath. Taking a 7 / 8" cable as an example, as shown in FIG. Figure 1 The inner conductor is a spiral corrugated copper pipe structure; the insulating layer is composed of physical foamed polyethylene of a skin / bubble / skin structure or a skin / bubble structure; the outer conductor is composed of an annular corrugated copper pipe; and the sheath is composed of polyethylene or low-smoke halogen-free flame-retardant polyolefin. Since the outer conductor is an annular corrugated structure, the minimum repeated bending radius thereof is 90 mm, which is not conducive to the use in complex environments such as narrow space tower top and many right-angle turns. Therefore, it is urgent to develop a 5G radio frequency coaxial cable suitable for use in complex environments. SUMMARY

[0003] The present application relates to the technical field of cable, in particular to a 5G radio frequency coaxial cable and a preparation method thereof.

[0004] The technical solution adopted by the present application to solve the technical problem is that a 5G radio frequency coaxial cable comprises, from inside to outside, an inner conductor, an inner skin layer, a foamed insulating layer, an outer skin layer, an outer conductor and a protective sheath layer; the inner conductor is a spiral corrugated inner conductor, the outer conductor is a spiral corrugated outer conductor, and the spiral direction of the inner conductor is the same as that of the outer conductor; the inner surface and the outer surface of the inner skin layer are both spiral-shaped, and the spiral shape of the inner surface of the inner skin layer cooperates with the spiral shape of the inner conductor after the inner skin layer is in close contact with the inner conductor; and the inner surface of the protective sheath layer is spiral-shaped, and the spiral shape of the inner surface of the protective sheath layer cooperates with the spiral shape of the outer conductor after the protective sheath layer is in close contact with the outer conductor. The inner conductor and the outer conductor are both spiral corrugated structures, the inner skin layer is in close contact with the inner conductor, and the protective sheath layer is in close contact with the outer conductor, so that the 5G radio frequency coaxial cable has good softness, high bending performance, is suitable for use in complex environments such as narrow space tower top and many right-angle turns, and has good electrical performance.

[0005] Further, specifically, the inner surface of the foamed insulating layer is spiral-shaped, and the spiral shape of the inner surface of the foamed insulating layer cooperates with the spiral shape of the outer surface of the inner skin layer.

[0006] Further, specifically, the outer surface of the inner conductor is formed with a spiral groove, and the outer surface of the outer conductor is formed with a spiral groove.

[0007] Further, specifically, the width of the copper band of the inner conductor is smaller than the width of the copper band of the outer conductor, and the thickness of the copper band of the inner conductor and the thickness of the copper band of the outer conductor are both 0.10mm-0.35mm.

[0008] Further, specifically, the thickness of the inner skin layer is 0.03-0.1mm.

[0009] Further, specifically, the foamed insulation layer is an insulation layer formed by polyethylene, a nucleating agent, and physical foaming of a gas, the gas being a mixture of CO2 and C4F8, or a mixture of N2 and C4F8, and the full-closed pore foaming degree is 80-84%.

[0010] Further, specifically, the thickness of the outer skin layer is 0.05mm-0.1mm.

[0011] A manufacturing method of a 5G radio frequency coaxial cable, for manufacturing the 5G radio frequency coaxial cable as described above, the manufacturing method comprising the following steps:

[0012] Step one, raw material detection: including detection of the copper band of the inner conductor and the copper band of the outer conductor;

[0013] Step two, manufacturing of the inner conductor: the copper band of the inner conductor detected in step one is put on a first banding rack, the surface of the copper band of the inner conductor is cleaned, the cleaned copper band of the inner conductor is precisely cut to make the width of the copper band of the inner conductor consistent, the precisely cut copper band of the inner conductor is formed, the formed copper band of the inner conductor is a tightly connected round tube with the seam upward, then the copper band of the inner conductor is welded to form a closed and smooth copper tube inner conductor, the copper tube inner conductor is calibrated, the outer surface of the copper tube inner conductor is embossed to form a spiral groove, and the outer surface of the copper tube inner conductor is embossed to form a spiral groove.

[0014] Step three, extruding the inner skin layer: the inner skin layer is extruded on the outer surface of the inner conductor in step two, the inner conductor in step two is put on a wire laying rack, the inner conductor is straightened, the straightened inner conductor is drawn and cleaned, the inner skin layer is heated by using low-density polyethylene, the inner skin layer is uniformly extruded on the outer surface of the drawn and cleaned inner conductor, the inner skin layer is tightly contacted with the inner conductor when the inner skin layer is extruded on the outer surface of the inner conductor, and the inner conductor with the extruded inner skin layer is cooled after the extrusion of the inner skin layer on the outer surface of the inner conductor is completed.

[0015] Step four, extruding the foamed insulation layer and the outer skin layer: extruding the foamed insulation layer and the outer skin layer on the inner skin layer of step three, the foamed insulation layer is an insulation layer formed by polyethylene, nucleating agent and physical foaming of gas, the polyethylene includes high density polyethylene and low density polyethylene, the weight percentage of the high density polyethylene, the low density polyethylene and the nucleating agent is 75% of high density polyethylene, 23% of low density polyethylene and 2% of nucleating agent respectively;

[0016] The high density polyethylene, the low density polyethylene and the nucleating agent are weighed according to the proportion and heated to a molten state to form a molten insulation, the gas is injected into the molten insulation, and the mixing is mixed to form a supersaturated gas material mixture, the gas material mixture is extruded on the surface of the inner skin layer to form a foamed insulation layer, at the same time, the outer skin layer is made of polyethylene material, the polyethylene is heated, and the heated polyethylene is extruded on the foamed insulation layer to form the outer skin layer, and then gradient cooling is performed through air cooling and then water cooling to ensure crystallization of the formed insulation layer, and finally blow drying is performed.

[0017] Step five: the outer conductor is made: the copper strip of the outer conductor detected in step one is placed through a second strip placing frame, the copper strip of the outer conductor is surface cleaned, the cleaned copper strip of the outer conductor is precisely cut to make the width of the copper strip of the outer conductor consistent, the precisely cut copper strip of the outer conductor is formed into a pipe, the pipe is tightly connected to form a round pipe, then welding is performed to form a closed smooth copper pipe outer conductor, the copper pipe outer conductor is calibrated, the inner conductor extruded with the foamed insulation layer and the outer skin layer in step four is placed into the calibrated copper pipe outer conductor, and the outer surface of the copper pipe outer conductor is embossed to form a spiral embossed outer conductor with spiral grooves, the spiral direction of the outer conductor is the same as the spiral direction of the inner conductor in step one.

[0018] Step six: extruding the protective sleeve layer: the protective sleeve material is linear low density polyethylene or low smoke halogen-free flame-retardant polyolefin, the linear low density polyethylene or the low smoke halogen-free flame-retardant polyolefin is dried and melted, the melted polyethylene sheath material or low smoke halogen-free flame-retardant polyolefin sheath material is extruded on the outer surface of the outer conductor of step five, the protective sleeve layer is extruded on the outer surface of the outer conductor and also subjected to vacuumizing treatment, the protective sleeve layer is in close contact with the outer surface of the outer conductor to complete the manufacturing of the protective sleeve layer, then the protective sleeve layer is cooled in a hot water tank with a temperature of 35°C, and then cooled in a cold water tank with a normal temperature, to form the outer conductor radio frequency coaxial cable.

[0019] Preferably, the embossing in the second step is performed by an embossing blade on an embossing device, and the thickness of the embossing blade is 2.2-2.45mm.

[0020] Further, specifically, the purity of the gas in the fourth step is 99.99%, and the gas is a mixture of CO2 and C4F8 or a mixture of N2 and C4F8, and the gas is in a liquid state before being injected into the molten insulator and is in a gaseous state after being injected into the molten insulator and being gasified at a high temperature.

[0021] The 5G radio frequency coaxial cable has the advantages that the inner conductor is a spiral corrugated inner conductor, the outer conductor is a spiral corrugated outer conductor, the inner skin layer is in close contact with the inner conductor, and the protective sheath layer is in close contact with the outer conductor, the inner and outer surfaces of the inner skin layer are spiral-shaped, and the inner surface of the protective sheath layer is spiral-shaped, so that the cable has good softness and high bending performance, can be bent arbitrarily, is suitable for use in complex environments such as narrow space tower tops and many right-angle turns, has good electrical performance, is highly practical, and ensures the performance of the cable while improving the bending performance. BRIEF DESCRIPTION OF DRAWINGS

[0022] The application will be further described below in combination with the drawings and examples.

[0023] Figure 1 is a schematic view of a prior art structure.

[0024] Figure 2 is a schematic view of the structure of the optimal embodiment of the application.

[0025] In the drawing, 1 is an inner conductor, 2 is an inner skin layer, 3 is a foamed insulating layer, 4 is an outer skin layer, 5 is an outer conductor, and 6 is a protective sheath layer. DETAILED DESCRIPTION

[0026] The application will be further described below in combination with the drawings and examples.

[0027] In the description of the present application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0028] In the description of the present application, it needs to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] As Figure 2 shown is the most preferred embodiment of the present application, a 5G radio frequency coaxial cable, from inside to outside, includes an inner conductor 1, an inner skin layer 2, a foamed insulation layer 3, an outer skin layer 4, an outer conductor 5 and a protective sleeve layer 6; the inner conductor 1 is a spiral corrugated inner conductor, the outer conductor 5 is a spiral corrugated outer conductor, the spiral direction of the inner conductor 1 is the same as that of the outer conductor 5; the inner surface and the outer surface of the inner skin layer 2 are both spiral, the spiral of the inner surface of the inner skin layer 2 cooperates with the spiral of the inner conductor 1 after the inner skin layer 2 is in close contact with the inner conductor 1; the inner surface of the protective sleeve layer 6 is spiral, the spiral of the inner surface of the protective sleeve layer 6 cooperates with the spiral of the outer conductor 5 after the protective sleeve layer 6 is in close contact with the outer conductor 5. The inner conductor 1 and the outer conductor 5 are both provided with a spiral corrugated structure, the inner skin layer 2 is in close contact with the inner conductor 1, and the protective sleeve layer 6 is in close contact with the outer conductor 5, so that the cable has good softness and high bending performance, and is suitable for use in complex environments such as narrow space, tower top and many right-angle turns, and has good electrical performance.

[0030] In the embodiment, the spiral direction of the inner conductor 1 can be leftward or rightward.

[0031] In the embodiment, the inner surface of the foamed insulation layer 3 presents a spiral shape, and the spiral shape of the inner surface of the foamed insulation layer 3 cooperates with the spiral shape of the outer surface of the inner sheath layer 2. The foamed insulation layer 3 is an insulation layer formed by polyethylene, a nucleating agent and physical foaming of a gas, which is a mixture of CO2 and C4F8 or a mixture of N2 and C4F8, and the full-closed cell foaming degree is 80-84%.

[0032] In the embodiment, the outer surface of the inner conductor 1 is formed with a spiral groove, and the outer surface of the outer conductor 5 is formed with a spiral groove. The width of the copper strip of the inner conductor 1 is smaller than the width of the copper strip of the outer conductor 5, and the thickness of the copper strip of the inner conductor 1 and the thickness of the copper strip of the outer conductor 5 are both 0.10-0.35 mm.

[0033] In the embodiment, the thickness of the inner sheath layer 2 is 0.03-0.1 mm, and the thickness of the outer sheath layer 4 is 0.05-0.1 mm.

[0034] A manufacturing method of a 5G radio frequency coaxial cable, used for manufacturing the 5G radio frequency coaxial cable as described above, and the manufacturing method comprises the following steps:

[0035] Step one, raw material detection: including detection of the copper strip of the inner conductor 1 and the copper strip of the outer conductor 5; detecting whether the copper strip of the inner conductor 1 meets the requirements, i.e. the width and thickness of the copper strip of the inner conductor 1; detecting whether the copper strip of the outer conductor 5 meets the requirements, i.e. the width and thickness of the copper strip of the outer conductor 5.

[0036] In step one, it also includes detection of whether the liquid gas material meets the requirements, i.e. whether the purity value of the liquid gas reaches 99.99%; and it also includes detection of the material of the foamed insulation layer and the material of the sheath layer.

[0037] Step two, manufacturing of the inner conductor 1: the copper strip of the inner conductor 1 detected in step one is placed on a first strip placing rack, the surface of the copper strip of the inner conductor 1 is cleaned, the cleaned copper strip of the inner conductor 1 is precisely cut to make the width of the copper strip of the inner conductor 1 consistent, the precisely cut copper strip of the inner conductor 1 is formed into a pipe, the formed pipe has a pipe joint upwardly and is tightly connected, then the pipe is welded to form a closed and smooth copper pipe inner conductor 1, the copper pipe inner conductor 1 is calibrated, the outer surface of the copper pipe inner conductor 1 is embossed after calibration, and the outer surface of the copper pipe inner conductor 1 is embossed into a spiral groove spiral embossed inner conductor;

[0038] Specifically, the copper strip of the inner conductor 1 is conveyed to the first precision cutting device after surface cleaning by the first cleaning device. The copper strip is cut by the high-precision cutter on the first precision cutting device to cut off the edges of the copper strip, so that the width of the copper strip of the inner conductor 1 is consistent, facilitating welding. The precision-cut inner conductor 1 copper strip is conveyed to the first forming equipment. The first forming equipment forms the precision-cut inner conductor 1 copper strip into a round tube with upwardly directed and closely connected pipe joints. Then, the first welding unit adopts automatic argon arc welding technology to weld the pipe joints, forming a closed and smooth copper pipe inner conductor 1. The copper pipe inner conductor 1 is conveyed to the first traction equipment after being calibrated by the calibration die. The first traction equipment controls the speed of the copper pipe inner conductor 1 entering the first corrugating equipment. At the same time, by controlling the rotating speed of the first corrugating equipment, the corrugating blade on the first corrugating equipment corrugates the copper pipe inner conductor 1. The outer surface of the copper pipe inner conductor 1 is corrugated into a spiral corrugated copper pipe inner conductor 1 with spiral grooves.

[0039] In step two, the corrugating is performed by the corrugating blade on the corrugating equipment. The thickness of the corrugating blade is 2.2-2.45 mm, forming a spiral corrugated copper pipe inner conductor 1 with spiral grooves. The inner conductor 1 after corrugating is not easy to be folded when being wound on a reel, thereby improving the stability of the manufacturing process and ensuring the quality of the product. Further, the depth of the spiral grooves formed by the corrugating blade on the inner conductor 1 is 2.2-2.5 mm, further improving the softness of the cable.

[0040] Step three, extruding the inner skin layer 2: The inner skin layer 2 is extruded on the outer surface of the inner conductor 1 after drawing and cleaning. The inner skin layer 2 is made of low-density polyethylene and is heated to be uniformly extruded on the outer surface of the inner conductor 1. The inner skin layer 2 is tightly contacted with the inner conductor 1 after being extruded on the outer surface of the inner conductor 1. After the extrusion of the inner skin layer 2 on the outer surface of the inner conductor 1 is completed, the inner conductor 1 with the extruded inner skin layer 2 is cooled;

[0041] Specifically, the inner conductor 1 is straightened by the straightener, the straightened inner conductor 1 is conveyed to the first drawing die for drawing, and then is cleaned by the second cleaning device, the cleaned inner conductor 1 enters the first extruding machine, the inner skin layer 2 is heated by using low-density polyethylene, the inner skin layer 2 is uniformly extruded and coated on the outer surface of the inner conductor 1 by the first extruding machine, the use of low-density polyethylene can improve the attenuation performance of the cable, the head of the first extruding machine is also provided with the first vacuum pumping device, the inner skin layer 2 is in close contact with the inner conductor 1, and the inner conductor 1 with the inner skin layer 2 is cooled after the extrusion coating of the inner skin layer 2 on the outer surface of the inner conductor 1 is completed; further, the head of the first extruding machine is also provided with a control valve at the connection with the first vacuum device, the control valve is used to control the adsorption effect between the inner skin layer 2 and the inner conductor 1, in the embodiment of the application, the inner skin layer 2 is tightly adsorbed on the inner conductor 1, and due to the closed vacuum pumping treatment, the inner skin layer 2 is thinned, the transmission performance is optimized, and the phenomenon that the inner skin layer 2 is broken or the inner skin layer 2 cannot be in close contact with the inner conductor 1 in the production process is avoided.

[0042] The inner conductor 1 with the inner skin layer 2 is cooled in step three by 2-3 air compression cooling devices, and the compressed air must be separated from oil and water to ensure the dryness of the surface of the inner skin layer 2. Compared with the water cooling method used in the prior art, the spiral groove on the outer surface of the inner conductor 1 of the application will not have residual water, and will not cause the VSWR index of the product to deteriorate.

[0043] In step four, the foamed insulation layer 3 and the outer skin layer 4 are coated on the inner skin layer 2 in step three, the foamed insulation layer 3 is an insulation layer formed by polyethylene, nucleating agent and physical foaming gas, the polyethylene includes high-density polyethylene and low-density polyethylene, and the weight percentage of the high-density polyethylene, the low-density polyethylene and the nucleating agent is 75% of high-density polyethylene, 23% of low-density polyethylene and 2% of nucleating agent respectively.

[0044] The high-density polyethylene, the low-density polyethylene and the nucleating agent are weighed according to the proportion, and are heated to a molten state to form a molten insulation body, the gas is injected into the molten insulation body and is mixed to form a supersaturated gas-material mixture, the gas-material mixture is extruded and coated on the surface of the inner skin layer 2 to form the foamed insulation layer 3, and the outer skin layer 4 is formed by using polyethylene material, the polyethylene is heated, the heated polyethylene is extruded and coated on the foamed insulation layer 3 to form the outer skin layer 4, and then air cooling and water cooling are performed for gradient cooling to ensure that the formed insulation layer is crystallized and finally dried.

[0045] Specifically, the high-density polyethylene, low-density polyethylene and nucleating agent are weighed according to the proportion and put into the second extruder for heating to form a molten insulator, the gas is injected into the molten insulator through the injector of the second extruder under the pressure of the pump, then the molten insulator with the injected gas is conveyed to the third extruder, the third extruder mixes and blends the molten insulator with the injected gas to form a supersaturated gas-material mixture, the inner conductor 1 with the inner skin layer 2 coated in step three is conveyed to the die of the third extruder, the gas-material mixture is extruded through the die of the third extruder to form the foamed insulating layer 3 on the surface of the inner skin layer 2, the die of the third extruder is a double-layer co-extrusion structure, and the outer skin layer 4 is made of polyethylene material, the polyethylene is heated in the fourth extruder, the fourth extruder is connected with the die of the third extruder, and the heated polyethylene is extruded through the die of the third extruder to form the outer skin layer 4 on the foamed insulating layer 3, then the product is subjected to gradient cooling through the air cooling device and then the cold water tank to ensure the crystallization of the formed insulating layer, and finally the product is dried through the drying device.

[0046] In step four, the purity of the gas is 99.99%, the gas is a mixture of CO2 and C4F8 or a mixture of N2 and C4F8, the gas is in a liquid state before being injected into the molten insulator, and the gas is in a gaseous state after being injected into the molten insulator and then gasified at high temperature, the full-closed cell foaming degree can be as high as 80-84%, which is higher than that of the product in the prior art, thereby improving the attenuation performance of the cable, reducing the weight of the foamed insulating layer, reducing the cost, and improving the material utilization.

[0047] Step five: outer conductor 5 manufacturing: the copper strip of the outer conductor 5 detected in step one is placed on the second strip placing rack, the copper strip of the outer conductor 5 is cleaned, the cleaned copper strip of the outer conductor 5 is precisely cut to make the width of the copper strip of the outer conductor 5 consistent, the precisely cut copper strip of the outer conductor 5 is formed into a pipe, the pipe is tightly connected in a circular tube shape with the pipe seam upward, then the copper pipe is welded to form a closed and smooth copper pipe outer conductor 5, the copper pipe outer conductor 5 is calibrated, the inner conductor 1 with the foamed insulating layer 3 and the outer skin layer 4 extruded in step four is placed in the calibrated copper pipe outer conductor 5, and the outer surface of the copper pipe outer conductor 5 is embossed to form a spiral corrugated outer conductor 5 with spiral grooves; the spiral direction of the outer conductor 5 is the same as the spiral direction of the inner conductor 1 in step one; compared with the annular embossed outer conductor 5 in the prior art, the spiral corrugated outer conductor 5 with spiral grooves further improves the flexibility of the 5G radio frequency coaxial cable.

[0048] Specifically, the copper strip of the outer conductor 5 is cleaned by the third cleaning device and then transmitted to the second fine cutting device. The copper strip is cut by a high-precision cutter to cut off the edges of the copper strip of the outer conductor 5, so that the width of the copper strip is consistent, facilitating welding. The fine-cut outer conductor 5 copper strip is transmitted to the second forming equipment. The second forming equipment forms the fine-cut outer conductor 5 copper strip into a tightly connected and round tubular shape with the pipe joint upward, and longitudinally wraps the inner conductor 1 with the foamed insulation layer 3 and the outer skin layer 4 of step four. Then, the second welding unit adopts automatic argon arc welding technology to weld the pipe joint, forming a closed and smooth copper pipe outer conductor 5. The copper pipe outer conductor 5 is subjected to two-draw through the second drawing die. After drawing, the outer diameter of the copper pipe outer conductor 5 is smaller than that of the smooth copper pipe outer conductor 5 before drawing. After drawing, the second traction equipment controls the speed of the smooth copper pipe outer conductor 5 entering the texturing equipment, and the second traction equipment provides pressure between the smooth copper pipe outer conductor 5 and the inner conductor 1 with the foamed insulation layer 3 and the outer skin layer 4 of step four. At the same time, by controlling the rotating speed of the second texturing equipment, the texturing blade on the second texturing equipment is textured on the copper pipe outer conductor 5. The copper pipe outer conductor 5 is textured into a spiral textured copper pipe outer conductor 5. The spiral direction of the outer conductor 5 is the same as the spiral direction of the inner conductor 1 in step one.

[0049] Step six: extruding a protective sheath layer 6: The protective sheath material is linear low-density polyethylene or low-smoke halogen-free flame-retardant polyolefin. The linear low-density polyethylene or low-smoke halogen-free flame-retardant polyolefin is dried and melted. The melted polyethylene sheath material or low-smoke halogen-free flame-retardant polyolefin sheath material is extruded and wrapped on the outer surface of the outer conductor 5 of step five. When the protective sheath layer 6 is extruded and wrapped on the outer surface of the outer conductor 5, vacuumizing treatment is also performed. After the protective sheath layer 6 is in close contact with the outer surface of the outer conductor 5, the production of the protective sheath layer 6 is completed. Then, the protective sheath layer 6 is cooled in a hot water tank with a temperature of 35℃, and then cooled in a cold water tank with a normal temperature, to produce a 5G radio frequency coaxial cable.

[0050] Specifically, the protective sheath material linear low-density polyethylene or low-smoke halogen-free flame-retardant polyolefin is dried by a drying equipment and melted in the fifth extruder. The melted polyethylene sheath material or low-smoke halogen-free flame-retardant polyolefin sheath material is extruded and wrapped on the outer surface of the outer conductor 5 of step five by a sheath extrusion die head. The head of the fifth extruder is also provided with a second vacuumizing device. After the protective sheath layer 6 is in close contact with the outer surface of the outer conductor 5, the production of the protective sheath layer 6 is completed. Then, the protective sheath layer 6 is cooled in a hot water tank with a temperature of 35℃, and then cooled in a cold water tank with a normal temperature, to produce a 5G radio frequency coaxial cable. Further, the head of the fifth extruder is connected with the second vacuumizing device and is also provided with a control valve. The control valve is used to control the adsorption effect between the protective sheath layer 6 and the outer conductor 5. In the embodiment of the present application, the protective sheath layer 6 is tightly adsorbed on the outer conductor 5, which greatly reduces the bending radius of the 5G radio frequency coaxial cable, from the original 90mm repeated bending radius to 55mm.

[0051] In the embodiment of the present application, the power of the first vacuum device and the second vacuum device is 2.2KW. The inner skin layer 2 is in close contact with the inner conductor 1, and the sheath layer is in close contact with the outer conductor 5, which further improves the flexibility of the 5G radio frequency coaxial cable.

[0052] For example, taking a 7 / 8" cable as an example, the 5G radio frequency coaxial cable of the prior art (as shown in Figure 1 ) and the embodiment of the present application are tested. The above tests all adopt the conventional test method in the art, which is not specifically limited here. The test results are shown in Table 1

[0053] Table 1 is the performance test results of the 5G radio frequency coaxial cable

[0054]

[0055] As can be seen from Table 1, the voltage standing wave ratio of the embodiment of the present application is less than that of the prior art. After a single bending, when the bending radius is 90mm (industry standard), the voltage standing wave ratio of the embodiment of the present application is less than that of the prior art. When the bending radius is 55mm, the voltage standing wave ratio of the embodiment of the present application is less than that of the prior art. In addition, in the prior art, when the bending radius is 55mm, when the standing wave test frequency band is 1880MHZ-2180MHZ, 2300MHZ-2500MHZ, 2500MHZ-2700MHZ, 4800MHZ-5000MHZ, the voltage standing wave ratio is greater than 1.2, which does not meet the specified value of the industry standard. The voltage standing wave ratio of the cable of the present application is still less than 1.2 when the bending radius is 55mm, and the voltage standing wave ratio of the present embodiment is large in each frequency band. It can be seen that the electrical performance of the 5G radio frequency coaxial cable of the present application is good, the bending performance is improved, the electrical performance of the cable is ensured, and the voltage standing wave ratio in the 4800MHZ-5000MHZ frequency band is 1.14, which meets the requirements of the transmission frequency of 5G.

[0056] The 5G radio frequency coaxial cable of the present application, the inner conductor 1 is a spiral corrugated inner conductor, the outer conductor 5 is a spiral corrugated outer conductor, the inner skin layer 2 is in close contact with the inner conductor 1, the protective sleeve layer 6 is in close contact with the outer conductor 5, the inner and outer surfaces of the inner skin layer 2 are spiral, and the inner surface of the protective sleeve layer 6 is spiral, so that the cable has good flexibility and high bending performance. The cable can be arbitrarily bent and is suitable for use in complex environments such as narrow space tower top, right angle turning and the like, has good electrical performance, high practicability, and improves the bending performance while ensuring the electrical performance of the cable.

[0057] With the above ideal embodiments according to the present application as the inspiration, through the above description, relevant staff can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A 5G radio frequency coaxial cable characterized by: It comprises, from inside to outside, an inner conductor (1), an inner skin layer (2), a foamed insulation layer (3), an outer skin layer (4), an outer conductor (5) and a protective jacket layer (6); The inner conductor (1) is a spiral corrugated inner conductor, the outer conductor (5) is a spiral corrugated outer conductor, and the spiral direction of the inner conductor (1) is the same as that of the outer conductor (5); The inner surface and the outer surface of the inner skin layer (2) are both spiral, and the spiral of the inner surface of the inner skin layer (2) cooperates with the spiral of the inner conductor (1) after the inner skin layer (2) is in close contact with the inner conductor (1); The inner surface of the protective jacket layer (6) is spiral, and the spiral of the inner surface of the protective jacket layer (6) cooperates with the spiral of the outer conductor (5) after the protective jacket layer (6) is in close contact with the outer conductor (5); The inner surface of the foamed insulation layer (3) is spiral, and the spiral of the inner surface of the foamed insulation layer (3) cooperates with the spiral of the outer surface of the inner skin layer (2); The foamed insulation layer (3) is an insulation layer formed by polyethylene, nucleating agent and gas physical foaming, the gas is a mixture of CO2 and C4F8 or a mixture of N2 and C4F8, and the full-closed pore foaming degree is 80-84%.

2. The 5G radio frequency coaxial cable of claim 1, wherein: The outer surface of the inner conductor (1) is formed with a spiral groove, and the outer surface of the outer conductor (5) is formed with a spiral groove.

3. The 5G radio frequency coaxial cable of claim 2, wherein: The width of the copper band of the inner conductor (1) is smaller than that of the outer conductor (5), and the thickness of the copper band of the inner conductor (1) and the outer conductor (5) is both 0.10-0.35 mm.

4. The 5G radio frequency coaxial cable of claim 1, wherein: The thickness of the inner skin layer (2) is 0.03-0.1 mm.

5. The 5G radio frequency coaxial cable of claim 1, wherein: The thickness of the outer skin layer (4) is 0.05-0.1 mm.

6. A method of making a 5G radio frequency coaxial cable, the method comprising: The manufacturing method of the 5G radio frequency coaxial cable comprises the following steps: ​ Step one, raw material detection: including the detection of the copper band of the inner conductor (1) and the copper band of the outer conductor (5); Step two, manufacturing of the inner conductor (1): the copper band of the inner conductor (1) detected in step one is put on a first banding frame, the surface of the copper band of the inner conductor is cleaned, the cleaned copper band of the inner conductor (1) is precisely cut to make the width of the copper band of the inner conductor (1) consistent, the precisely cut copper band of the inner conductor (1) is formed, the formed copper band of the inner conductor (1) is formed into a pipe with a gap upwards and closely connected, then welded into a closed and smooth copper pipe inner conductor, the copper pipe inner conductor is calibrated, the outer surface of the copper pipe inner conductor is corrugated after calibration, and the outer surface of the copper pipe inner conductor is corrugated into a spiral corrugated inner conductor with a spiral groove; Step three, extruding the inner skin layer (2): the inner skin layer (2) is coated outside the inner conductor (1) in step two, the inner conductor (1) in step two is put on the wire rack, the inner conductor (1) is straightened, the straightened inner conductor (1) is drawn and cleaned, the inner skin layer (2) is heated by low-density polyethylene, the inner skin layer (2) is uniformly extruded and coated on the outer surface of the inner conductor (1) after drawing and cleaning, the inner skin layer is extruded and coated on the outer surface of the inner conductor, and the inner skin layer (2) is tightly contacted with the inner conductor (1), the inner skin layer (2) is extruded and coated on the outer surface of the inner conductor (1), and the inner conductor (1) with the inner skin layer (2) is cooled; Step four, extruding the foamed insulation layer (3) and the outer skin layer (4): the foamed insulation layer (3) and the outer skin layer (4) are coated outside the inner skin layer (2) in step three, the foamed insulation layer (3) is an insulation layer formed by polyethylene, nucleating agent and gas physical foaming, the polyethylene includes high-density polyethylene and low-density polyethylene, the weight percentage of the high-density polyethylene, the low-density polyethylene and the nucleating agent is respectively 75% of the high-density polyethylene, 23% of the low-density polyethylene and 2% of the nucleating agent; The high-density polyethylene, the low-density polyethylene and the nucleating agent are weighed according to the proportion, heated to a molten state to form a molten insulator, the gas is injected into the molten insulator, and the gas material mixture is mixed to form a supersaturated gas material mixture, the gas material mixture is extruded and coated on the surface of the inner skin layer (2) to form the foamed insulation layer (3), and the outer skin layer (4) is made of polyethylene material, the polyethylene is heated, the heated polyethylene is extruded and coated on the foamed insulation layer (3) to form the outer skin layer (4), and then air cooling and water cooling are performed for gradient cooling to ensure that the crystallization of the formed insulation layer, and finally dried; Step five: the outer conductor (5) is made: the copper strip of the outer conductor (5) detected in step one is put on the second wire rack, the surface of the copper strip of the outer conductor (5) is cleaned, the cleaned copper strip of the outer conductor (5) is precisely cut to make the width of the copper strip of the outer conductor (5) consistent, the precisely cut copper strip of the outer conductor (5) is formed, the copper strip of the outer conductor (5) is formed into a pipe joint upward and closely connected round pipe, and then welded into a closed smooth copper pipe outer conductor, the copper pipe outer conductor is calibrated, the inner conductor (1) with the foamed insulation layer (3) and the outer skin layer (4) in step four is put into the calibrated copper pipe outer conductor, and the outer surface of the copper pipe outer conductor is embossed, the outer surface of the copper pipe outer conductor is embossed into a spiral type corrugated outer conductor with spiral grooves; the spiral direction of the outer conductor (5) is the same as the spiral direction of the inner conductor (1) in step one; Step six: extruding the protective sheath layer (6): the protective sheath layer (6) is made of linear low-density polyethylene or low-smoke halogen-free flame-retardant polyolefin, the linear low-density polyethylene or the low-smoke halogen-free flame-retardant polyolefin is dried and melted, and the melted polyethylene sheath material or low-smoke halogen-free flame-retardant polyolefin sheath material is extruded and coated on the outer surface of the outer conductor (5) in step five, the protective sheath layer (6) is extruded and coated on the outer surface of the outer conductor (5) and is also subjected to vacuumizing treatment, the protective sheath layer (6) is in close contact with the outer surface of the outer conductor (5) to complete the production of the protective sheath layer (6), and then the outer conductor (5) is cooled in a hot water tank with a temperature of 35℃ and then in a cold water tank with a normal temperature, thereby producing the outer conductor (5) radio frequency coaxial cable.

7. The method of producing a 5G radio frequency coaxial cable according to claim 6, wherein: In the step two, the embossing is performed by an embossing blade on an embossing device, and the thickness of the embossing blade is 2.2-2.45 mm.

8. The method of producing a 5G radio frequency coaxial cable of claim 6, wherein: In the step four, the purity of the gas is 99.99%, and the gas is a mixture of CO2 and C4F8 or a mixture of N2 and C4F8, the gas is in a liquid form before being injected into the molten insulator, and is in a gaseous form after being injected into the molten insulator and being gasified at a high temperature.

Images