A low-loss radio frequency coaxial cable

Abstract

This utility model discloses a low-loss radio frequency coaxial cable, including a cable structure comprising a cable body and an insulating layer disposed on the cable body. The cable body includes a center conductor formed by stranding multiple copper wires, and a graphene film is deposited on the center conductor. The insulating layer includes an inner layer sleeved on the graphene film, and an outer layer sleeved on the inner layer. The inner layer is made of foamed polytetrafluoroethylene (PTFE), and the outer layer is made of solid PTFE. By setting the insulating layers, and with the dielectric constant of the inner layer increasing from low to high, a gradient insulation structure is achieved from the inside to the outside, optimizing impedance matching and effectively reducing phase delay and loss of transmitted signals. The graphene film, due to its excellent conductivity and stability, reduces the surface roughness of the center conductor, reducing skin effect loss during signal transmission. The inner shielding layer utilizes the high conductivity of copper foil and the electromagnetic shielding properties of graphene to effectively block electromagnetic interference.

Description

Technical Field

[0001] This utility model relates to the field of radio frequency coaxial cable technology, and in particular to a low-loss radio frequency coaxial cable. Background Technology

[0002] As the core carrier for radio frequency (RF) signal transmission, RF coaxial cables have irreplaceable and widespread applications in fields such as communications, radar, and test and measurement. In the communications field, from the construction of mobile communication base stations and the networking of wireless communication systems to indoor wireless signal coverage (such as signal transmission in subway tunnels and large buildings), and even the high-frequency signal interaction of satellite communications, all rely on their stable transmission. In the radar field, advanced equipment such as phased array radar and millimeter-wave radar rely on RF coaxial cables to achieve precise signal transmission and reception and processing, ensuring the efficient operation of detection and tracking functions. In the test and measurement field, network analyzers, spectrum analyzers, and other equipment need to use them to transmit signals when testing RF circuits and devices to ensure accurate and reliable test results.

[0003] However, traditional RF coaxial cables have many performance bottlenecks: at the conductor level, due to the skin effect and the inherent resistance of the material, electrical energy is significantly lost as it is converted into heat during signal transmission; the insulating medium suffers from signal attenuation and dispersion due to unstable dielectric constant and the absorption of signals by the material; in terms of electromagnetic interference, complex external electromagnetic environments can easily intrude, and the cable itself is also prone to signal leakage, interfering with surrounding equipment; in terms of temperature stability, changes in ambient temperature or the cable itself heating up will change the conductor resistance and dielectric constant, further degrading transmission performance, making it difficult for traditional cables to meet the increasingly stringent requirements for low-loss transmission.

[0004] In view of this, the present invention is proposed to solve the above-mentioned technical problems. Utility Model Content

[0005] The purpose of this invention is to provide a low-loss radio frequency coaxial cable to solve the technical problems of significant energy loss due to the conversion of electrical energy into heat energy and unstable dielectric constant of the insulating medium in existing low-loss radio frequency coaxial cables.

[0006] The technical solution of this utility model is: a low-loss radio frequency coaxial cable, including a cable structure;

[0007] The cable structure includes a cable body and an insulation layer disposed on the cable body. The cable body includes a center conductor, which is formed by multiple strands of copper wire twisted together. A graphene film is coated on the center conductor. The insulation layer includes an inner layer sleeved on the graphene film and an outer layer sleeved on the inner layer. The inner layer is foamed polytetrafluoroethylene, and the outer layer is solid polytetrafluoroethylene.

[0008] Furthermore, a shielding layer is provided on the insulating layer, the shielding layer including an inner shielding layer, an intermediate shielding layer and an outer shielding layer sequentially disposed on the insulating layer.

[0009] Furthermore, the inner shielding layer is composed of stacked copper foil and graphene sheets, and the layers of copper foil and graphene sheets are bonded together by conductive adhesive.

[0010] The intermediate shielding layer is made of copper alloy wire mesh;

[0011] The outer shielding layer is a conductive rubber layer;

[0012] The middle shielding layer and the outer shielding layer are tightly bonded together by heat pressing.

[0013] Furthermore, it also includes a sheath, which includes a buffer layer fitted on the outer shielding layer, a protective layer fitted on the buffer layer, the buffer layer being squeezed and wrapped around the outer shielding layer, and the buffer layer and the protective layer being firmly bonded together by a secondary injection molding process.

[0014] Furthermore, radio frequency connectors are welded to both ends of the cable structure.

[0015] Furthermore, multiple strands of silver alloy wire are also interspersed among the multiple copper wires.

[0016] Furthermore, a monitoring layer is provided between the outer shielding layer and the buffer layer. The monitoring layer includes a flexible printed circuit board and multiple micro sensors, including a temperature sensor, a strain sensor, and a humidity sensor. The multiple micro sensors are uniformly soldered on the flexible printed circuit board, which has a cylindrical structure. The flexible printed circuit board is electrically connected to the outer shielding layer through conductive adhesive, and the flexible printed circuit board is electrically connected to external monitoring equipment.

[0017] Furthermore, the insulation layer thickness is 0.4-3.2 mm.

[0018] By adopting the above technical solution, this utility model has the following beneficial effects:

[0019] 1. By setting an insulating layer with a dielectric constant that increases from low to high from the inner to the outer layer, an insulating structure with a gradient change from the inside to the outside is achieved, optimizing impedance matching and effectively reducing phase delay and loss of transmitted signals.

[0020] 2. By using a graphene film, which has excellent conductivity and stability, the surface roughness of the central conductor is reduced, thus reducing skin effect loss during signal transmission.

[0021] 3. The inner shielding layer utilizes the high conductivity of copper foil and the electromagnetic shielding properties of graphene to effectively block electromagnetic interference. The alloy wire mesh of the middle shielding layer ensures flexibility while further enhancing the shielding effect. The outer shielding layer uses a conductive rubber layer, which has good flexibility and sealing properties, and can prevent external moisture, dust and other factors from affecting the internal structure of the cable, while also enhancing the shielding ability against low-frequency electromagnetic interference. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but do not constitute an undue limitation of the present invention. Obviously, the drawings described below are merely some embodiments; those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0023] Figure 1 This is a schematic diagram of the structure of the low-loss radio frequency coaxial cable provided in the embodiments of this application;

[0024] Figure 2 A schematic diagram of the cable structure of the low-loss radio frequency coaxial cable provided in the embodiments of this application;

[0025] Figure 3 A schematic diagram of the cable body of the low-loss radio frequency coaxial cable provided in the embodiments of this application;

[0026] Figure 4 A schematic diagram of the cable body and insulation layer of the low-loss radio frequency coaxial cable provided in the embodiments of this application;

[0027] Figure 5 This is a schematic diagram of the shielding layer of the low-loss radio frequency coaxial cable provided in the embodiments of this application.

[0028] Reference numerals: 1. Cable structure; 2. RF connector; 11. Cable body; 12. Insulation layer; 13. Shielding layer; 14. Sheath; 111. Center conductor; 112. Graphene film; 131. Inner shielding layer; 132. Middle shielding layer; 133. Outer shielding layer.

[0029] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0030] The specific embodiments of this utility model will be described in further detail with reference to the accompanying drawings.

[0031] See Figures 1 to 5As shown, this application embodiment provides a low-loss radio frequency coaxial cable, including a cable structure 1. The cable structure 1 includes a cable body 11 and an insulation layer 12 disposed on the cable body 11. The cable body 11 includes a center conductor 111, which is formed by stranding multiple copper wires. It has high conductivity and good flexibility to ensure the efficiency and stability of signal transmission. Under some special requirements, silver-plated copper wires can also be used. The silver plating layer can further reduce the surface resistance of the center conductor 111 and reduce the loss during signal transmission. Its diameter is generally between 0.5-3mm and can be adjusted according to the cable specifications and transmission frequency. A graphene film 112 is coated on the center conductor 111. The insulation layer 12 includes an inner layer sleeved on the graphene film 112 and an outer layer sleeved on the inner layer. The inner layer is foamed polytetrafluoroethylene and the outer layer is solid polytetrafluoroethylene. The graphene film 112 has excellent conductivity and stability, reduces the surface roughness of the center conductor 111, and reduces skin effect loss during signal transmission.

[0032] It should be noted that the insulation layer 12 is cylindrical in shape and tightly wraps around the outside of the cable body 11, providing electrical isolation and mechanical support for the cable body 11. Both the inner and outer layers of the insulation layer 12 adopt a spiral structure, with the inner layer having a low dielectric constant and the outer layer having a high dielectric constant, achieving a gradient insulation structure from the inside to the outside. This optimizes impedance matching and effectively reduces the phase delay and loss of transmitted signals. The inner and outer layers are tightly bonded together through a precise co-extrusion process, ensuring a seamless connection between the insulation materials with different dielectric constants and the cable body 11, thus guaranteeing the reliability of the insulation performance.

[0033] See some possible implementations. Figure 2 and Figure 5 As shown, a shielding layer 13 is fitted onto the insulating layer 12. The shielding layer 13 includes an inner shielding layer 131, a middle shielding layer 132, and an outer shielding layer 133 sequentially fitted onto the insulating layer 12. The inner shielding layer 131 is composed of stacked copper foil and graphene sheets, and the layers of copper foil and graphene sheets are bonded together with conductive adhesive to ensure good electrical connection. The middle shielding layer 132 is a copper alloy wire mesh, and the outer shielding layer 133 is a conductive rubber layer. The middle shielding layer 132 and the outer shielding layer 133 are tightly bonded together by heat pressing.

[0034] In the above scheme, the inner shielding layer 131 utilizes the high conductivity of copper foil and the electromagnetic shielding performance of graphene to effectively block electromagnetic interference. The alloy wire mesh of the middle shielding layer 132 ensures flexibility while further improving the shielding effect. The outer shielding layer 133 uses a conductive rubber layer, which has good flexibility and sealing performance, and can prevent external moisture, dust and other factors from affecting the internal structure of the cable. At the same time, it enhances the shielding ability against low-frequency electromagnetic interference, protects the internal signal transmission of the cable body 11 from external electromagnetic interference and prevents internal signal leakage.

[0035] In some possible implementations, the low-loss radio frequency coaxial cable provided in this application embodiment further includes a sheath 14. The sheath 14 includes a buffer layer sleeved on the outer shielding layer 133. A protective layer is sleeved on the buffer layer. The buffer layer is squeezed and wrapped on the outer shielding layer 133. The buffer layer and the protective layer are firmly bonded together by a secondary injection molding process, so that the buffer layer and the protective layer have good adhesion and ensure the structural stability of the sheath 14.

[0036] In the above scheme, the buffer layer is thermoplastic polyurethane, which can buffer external impact and protect the internal structure of the cable. The protective layer is polycarbonate with added carbon fiber reinforcement, which improves the mechanical strength and wear resistance of the sheath 14, and at the same time gives the sheath 14 a certain antistatic property. The sheath 14 has a cylindrical structure. The thickness of the buffer layer is 0.3-1.2mm, and the thickness of the protective layer is 0.4-1.5mm. The appropriate selection is made according to the cable's operating environment and mechanical strength requirements.

[0037] See some possible implementations. Figure 2 As shown, both ends of the cable structure 1 are welded with radio frequency connectors 2. The welding is done by ultrasonic welding, which can achieve an electrical connection with extremely low resistance without damaging the graphene film 112 on the surface of the central conductor 111, thus ensuring efficient signal transmission.

[0038] In some possible implementations, multiple strands of silver alloy wire are also interspersed between the multiple copper wires to improve the flexibility of the conductor, reduce AC resistance, and reduce signal transmission loss.

[0039] In some possible implementations, a monitoring layer is also provided between the outer shielding layer 133 and the buffer layer for real-time monitoring of the working status and environmental parameters inside the cable. The monitoring layer includes a flexible printed circuit board and multiple micro sensors, including temperature sensors, strain sensors, and humidity sensors. Multiple micro sensors are uniformly soldered on the flexible printed circuit board, which has a cylindrical structure. The flexible printed circuit board is electrically connected to the outer shielding layer 133 through conductive adhesive for signal transmission. The flexible printed circuit board is also electrically connected to external monitoring equipment to realize real-time data transmission and processing.

[0040] In some possible implementations, the thickness of insulation layer 12 is 0.4-3.2 mm, which can be precisely adjusted according to cable characteristics and operating frequency.

[0041] Working principle

[0042] When an RF signal is applied to the center conductor 111, the skin effect loss is reduced due to the graphene film 112 on the surface of the center conductor 111 and the stranded structure, enabling efficient signal transmission. The unique spiral gradient structure of the insulating layer 12 optimizes impedance matching, reducing signal phase delay and loss.

[0043] The multi-layer composite structure of the shielding layer 13 works together, with the inner shielding layer 131 consisting of a copper foil-graphene composite layer, the middle shielding layer 132 consisting of a copper alloy wire braided mesh, and the outer shielding layer 133 consisting of a conductive rubber layer. These layers effectively shield external electromagnetic interference from different frequency bands and angles, while preventing internal signal leakage.

[0044] During cable operation, the micro-sensors in the monitoring layer monitor parameters such as temperature, strain, and humidity inside the cable in real time. When these parameters become abnormal, the data is transmitted to external monitoring equipment via a flexible printed circuit board, so that staff can promptly identify potential problems with the cable, carry out maintenance and handling, and ensure that the cable is always in good working condition, thereby achieving stable and reliable transmission of radio frequency signals under low-loss conditions.

[0045] This specific embodiment is merely an explanation of the utility model and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of protection of this utility model.

Claims

1. A low-loss radio frequency coaxial cable, characterized by, Including cable structure (1); The cable structure (1) includes a cable body (11) and an insulation layer (12) disposed on the cable body (11). The cable body (11) includes a center conductor (111), which is formed by twisting multiple copper wires. A graphene film (112) is coated on the center conductor (111). The insulation layer (12) includes an inner layer sleeved on the graphene film (112) and an outer layer sleeved on the inner layer. The inner layer is foamed polytetrafluoroethylene, and the outer layer is solid polytetrafluoroethylene.

2. The low-loss radio frequency coaxial cable according to claim 1, characterized in that, A shielding layer (13) is provided on the insulating layer (12), and the shielding layer (13) includes an inner shielding layer (131), a middle shielding layer (132) and an outer shielding layer (133) sequentially disposed on the insulating layer (12).

3. The low-loss radio frequency coaxial cable according to claim 2, characterized in that, The inner shielding layer (131) is made of stacked copper foil and graphene sheets, and the layers of copper foil and graphene sheets are bonded together by conductive adhesive. The intermediate shielding layer (132) is a copper alloy wire mesh; The outer shielding layer (133) is a conductive rubber layer; The intermediate shielding layer (132) and the outer shielding layer (133) are tightly bonded together by hot pressing.

4. The low-loss radio frequency coaxial cable according to claim 2 or 3, characterized in that, It also includes a sheath (14), which includes a buffer layer fitted on the outer shielding layer (133), a protective layer fitted on the buffer layer, the buffer layer being squeezed and wrapped on the outer shielding layer (133), and the buffer layer and the protective layer being firmly bonded together by a secondary injection molding process.

5. The low-loss radio frequency coaxial cable according to claim 1, characterized in that, The cable structure (1) has radio frequency connectors (2) welded to both ends.

6. The low-loss radio frequency coaxial cable according to claim 5, characterized in that, Multiple strands of silver alloy wire are also provided between the multiple copper wires.

7. The low-loss radio frequency coaxial cable according to claim 4, characterized in that, A monitoring layer is also provided between the outer shielding layer (133) and the buffer layer. The monitoring layer includes a flexible printed circuit board and multiple micro sensors, including a temperature sensor, a strain sensor and a humidity sensor. The multiple micro sensors are uniformly soldered on the flexible printed circuit board, and the flexible printed circuit board has a cylindrical structure. The flexible printed circuit board is electrically connected to the outer shielding layer (133) through conductive adhesive, and the flexible printed circuit board is electrically connected to an external monitoring device.

8. The low-loss radio frequency coaxial cable according to claim 6, characterized in that, The insulation layer (12) has a thickness of 0.4-3.2 mm.

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