Composite radio frequency coaxial cable

Abstract

The utility model relates to a composite radio frequency coaxial cable. The cable comprises an inner conductor which is of a spiral tubular structure; the optical fiber is embedded in the inner conductor, and an optical fiber filling ointment is filled between the optical fiber and the inner conductor; the insulating layer is arranged on the outer side of the inner conductor; the shielding layer is arranged on the outer side of the insulating layer; and the sheath layer is arranged on the outer side of the shielding layer. According to the utility model, the optical cable and the radio frequency coaxial cable are of an integrated structure, optical waves and radio frequency signals can be transmitted simultaneously, the advantages of the radio frequency coaxial cable structure and the optical cable transmission performance are combined, and the problems of easy damage, signal interference, low construction efficiency, poor compatibility with the existing system and the like of the optical cable in the prior art are solved; efficient and stable transmission of light wave and radio frequency signals is achieved, and meanwhile construction cost and difficulty are reduced.

Description

Technical Field

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

[0002] With the rapid development of communication technologies, especially 5G networks, the demand for high-bandwidth and high-reliability signal transmission in communication systems is increasing. In various application scenarios such as 5G base station construction and intelligent building communication systems, it is often necessary to transmit optical signals and radio frequency signals simultaneously.

[0003] Existing technologies typically employ the method of laying optical fibers and radio frequency coaxial cables separately to achieve dual signal transmission, but this has the following significant drawbacks:

[0004] The separate deployment of optical fiber and radio frequency (RF) cables results in a complex cabling system structure, large space occupation, cumbersome construction process, increased construction time and labor costs, especially in space-constrained locations. Secondly, in practical engineering applications, due to the relatively low mechanical strength of optical fibers, they are easily damaged by bending, compression, and other external forces during laying or operation, thus affecting the stability of optical signal transmission. Thirdly, although some existing optoelectronic composite cables integrate optical fiber and RF coaxial cable into a single sheath, unreasonable structural design leads to mutual interference between optical and electrical signals, and insufficient mechanical protection measures for the optical fiber make it difficult to withstand external impacts and bending in complex environments. Furthermore, some composite cables differ significantly in structural dimensions from standard RF coaxial cables, making them incompatible with existing communication systems and requiring adaptation and modification of existing equipment, further increasing system modification costs and technical implementation difficulties.

[0005] Traditional optical fiber composite cable technologies mainly include the following structural forms: one is that the optical fiber and the radio frequency cable are laid completely separately; the other is that the optical fiber and the radio frequency cable are twisted together and arranged in the same sheath. However, these solutions have the following drawbacks:

[0006] Optical signals and radio frequency signals are transmitted through separate transmission units. When deployed in close proximity in space, they are easily affected by external electromagnetic interference, especially the photosensitive elements in the optical receiving module.

[0007] Optical fibers are quite brittle, especially when passing through building gaps, being laid in bends, or in high-frequency vibration scenarios, they are very prone to micro-bending, cracks, or even fiber breakage, which seriously affects communication quality.

[0008] The overall outer diameter of split-type or multi-core cables is relatively large, which is not conducive to flexible wiring in space-constrained environments. Summary of the Invention

[0009] Therefore, this utility model provides a composite radio frequency coaxial cable, which integrates optical fiber and radio frequency coaxial cable into one structure, enabling simultaneous transmission of optical waves and radio frequency signals. It combines the advantages of radio frequency coaxial cable structure and optical fiber transmission performance, solving the problems of easy damage to optical fiber, signal interference, low construction efficiency and poor compatibility with existing systems in the prior art, achieving efficient and stable transmission of optical waves and radio frequency signals, while reducing construction costs and difficulties.

[0010] To solve the above-mentioned technical problems, this utility model provides a composite radio frequency coaxial cable, comprising:

[0011] The inner conductor has a helical tubular structure;

[0012] An optical fiber is embedded inside the inner conductor, and the space between the optical fiber and the inner conductor is filled with optical fiber filling grease.

[0013] An insulating layer is disposed on the outside of the inner conductor;

[0014] A shielding layer is disposed on the outside of the insulating layer;

[0015] A sheath layer is disposed on the outside of the shielding layer.

[0016] In one embodiment of this utility model, the inner conductor is a spiral tubular structure formed by welding metal strips and then corrugating them.

[0017] In one embodiment of this utility model, the material of the metal strip includes one of copper, aluminum, aluminum alloy, or copper alloy.

[0018] In one embodiment of this utility model, the thickness of the metal strip is 0.1-0.3 mm.

[0019] In one embodiment of this utility model, the pitch of the inner conductor is 3-10mm, and the tolerance of the crest and trough of the crest is within ±0.5mm.

[0020] In one embodiment of this utility model, the gap between the inner diameter of the inner conductor and the outer diameter of the optical fiber is 1-10 mm.

[0021] In one embodiment of this utility model, the thickness of the insulating layer is 1-10 mm, including polytetrafluoroethylene, polyethylene or foamed polyethylene.

[0022] In one embodiment of this utility model, the shielding efficiency of the shielding layer is ≥100dB, including an aluminum foil shielding layer, a copper foil shielding layer, a metal mesh layer, or a corrugated metal shielding layer.

[0023] In one embodiment of this utility model, the thickness of the sheath layer is 1-3 mm, and its material includes low-smoke halogen-free polyolefin.

[0024] In one embodiment of this utility model, the optical fiber includes single-mode optical fiber, multimode optical fiber, optical fiber bundle tube, semi-finished optical cable, or finished optical cable.

[0025] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art:

[0026] The present invention discloses a composite radio frequency coaxial cable that integrates an optical fiber channel within a spiral-structured metal tubular inner conductor, embedding the optical fiber at the center of the cable structure. The shielding performance of the metal conductor enhances the resistance to electromagnetic interference, and the tubular structure provides radial protection for the optical fiber, preventing bending damage. This enables stable and efficient synchronous transmission of optical waves and radio frequency signals, while simplifying the wiring and construction process, reducing installation space requirements, and improving the reliability and economy of the overall communication system.

[0027] The optical fiber in this composite RF coaxial cable is encased within the inner conductor, providing excellent mechanical protection for the fiber. The spiral tubular structure and welded corrugated design of the inner conductor effectively disperse external pressure and tension, preventing damage from compression, stretching, and bending, thus extending the cable's lifespan and improving the reliability of optical signal transmission.

[0028] This composite RF coaxial cable is designed without altering the structural dimensions of existing RF coaxial cables. Therefore, it can directly replace traditional RF coaxial cables during installation and use, without requiring large-scale modifications to existing equipment and wiring. This not only reduces usage costs but also improves compatibility with existing communication systems, facilitating widespread application.

[0029] This composite RF coaxial cable allows for the simultaneous laying of optical fiber and RF coaxial cable during construction, avoiding the cumbersome process of laying two types of cables separately, saving construction time and costs, and greatly improving construction efficiency. This advantage is particularly evident in large-scale communication engineering projects.

[0030] The spiral tubular structure of the inner conductor of this composite RF coaxial cable increases the overall bending performance of the cable, making it easier to bypass obstacles and bend during installation, adapting to various complex wiring environments and further improving the convenience of installation. Attached Figure Description

[0031] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0032] Figure 1 This is a cross-sectional view of the composite radio frequency coaxial cable of this utility model.

[0033] Figure 2 This is a front view of the composite radio frequency coaxial cable of this utility model.

[0034] Explanation of reference numerals in the instruction manual:

[0035] 1. Optical fiber; 2. Inner conductor; 3. Insulation layer; 4. Shielding layer; 5. Sheath layer. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0037] In this utility model, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this utility model, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.

[0038] In this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number; "above," "below," "within," etc. are understood to include the stated number. In the description of this utility model, if "first" or "second" is used, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0039] In this utility model, unless otherwise explicitly defined, terms such as "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model based on the specific content of the technical solution.

[0040] Reference Figure 1 , Figure 2 As shown, the present invention provides a composite radio frequency coaxial cable, comprising:

[0041] Inner conductor 2 has a helical tubular structure;

[0042] Optical fiber 1 is embedded inside the inner conductor 2, and optical fiber filling grease is filled between it and the inner conductor 2;

[0043] Insulating layer 3 is disposed on the outside of the inner conductor 2;

[0044] Shielding layer 4 is disposed on the outside of insulating layer 3;

[0045] Sheath layer 5 is disposed on the outside of shielding layer 4.

[0046] With the above setup, the optical fiber 1 (optical cable) is placed in the hollow inner conductor 2 of the radio frequency coaxial cable, which can effectively protect the optical fiber 1 from damage and resist compressive and tensile mechanical stress.

[0047] The inner conductor 2 of the spiral tubular structure can play a stress dispersion role. That is, when the cable bends, the optical fiber 1 can undergo elastic deformation with the inner conductor 2, and the minimum bending radius is only 2 / 3 of that of the traditional optical cable. In addition, the optical fiber 1 is placed in the inner conductor 2 of the spiral tubular structure, which can improve the compressive strength, and greatly improve the overall cable's compressive strength, impact resistance and tensile strength.

[0048] Furthermore, this composite RF coaxial cable meets the transmission requirements of both optical and RF signals, enabling the simultaneous transmission of optical and electromagnetic signals without mutual interference. The inner metal conductor 2 protects the internal optical signal transmission from external interference while also shielding it from external electromagnetic interference. The shielding layer 4 protects the internal RF signal transmission from external interference while also shielding it from external electromagnetic interference.

[0049] In one embodiment, the inner conductor 2 is a spiral tubular structure formed by welding metal strips and then corrugating them.

[0050] It should be noted that the inner conductor 2 is made of metal strip by precision welding; the metal strip is cleaned and formed into an approximately cylindrical structure by a U-shaped forming mold, then welded into a sealed tubular structure at the welding mold, and then corrugated; the optical fiber 1, together with high-viscosity optical fiber filling grease, is inserted into the spiral tube of the inner conductor 2 at the U-shaped forming mold; the optical fiber filling grease plays a certain role in vibration and impact resistance of the optical fiber 1, and at the same time plays a role in preventing moisture intrusion.

[0051] Specifically, the oxidation induction period (10℃ / min, 190℃) of the optical fiber filling grease is ≥20min, which means the time required for the material to begin to undergo an oxidation reaction at a specific heating rate (10℃ / min) and a constant temperature (190℃).

[0052] Relative permittivity εr: less than or equal to 2.30 at a frequency of 1 MHz and a temperature of 23℃ ± 2℃; Dielectric loss factor tgδ: less than or equal to 1 × 10⁻⁶ at a frequency of 1 MHz and a temperature of 23℃ ± 2℃. -3Volume resistivity ρv: greater than or equal to 1×10⁻⁶ at a temperature of 23℃±2℃. 13 Ω·cm;

[0053] Density (20℃) ≤0.88g / cm³ 3 The mass per unit volume of the ointment, measured at 20℃.

[0054] Before welding the spiral-shaped inner conductor 2, the optical fiber 1 is filled with high-viscosity optical fiber filling grease to ensure that the optical fiber 1 is in the center position and avoid stress concentration.

[0055] In one embodiment, the metal strip is made of copper, aluminum, aluminum alloy, or copper alloy, or other metal materials with good electrical conductivity.

[0056] In one embodiment, the thickness of the metal strip is 0.1-0.3 mm. Furthermore, the pitch of the inner conductor 2 is 3-10 mm, and the tolerance for the crests and troughs of the rolled edges is within ±0.5 mm. These features further enhance the stress dispersion effect of the inner conductor 2, significantly improving its ability to disperse bending, impact, and lateral pressure loads while ensuring mechanical strength.

[0057] In one embodiment, the gap between the inner diameter of the inner conductor 2 and the outer diameter of the optical fiber 1 is 1-10 mm, and the physical isolation between the optical signal and the radio frequency signal is achieved by using an air layer (optical fiber filling grease).

[0058] In one embodiment, the insulation layer 3 has a thickness of 1-10 mm and includes polytetrafluoroethylene, polyethylene, or foamed polyethylene.

[0059] In one embodiment, the shielding layer 4 has a shielding efficiency of ≥100dB, blocking the leakage of radio frequency signals to the optical fiber 1, and includes an aluminum foil shielding layer 4, a copper foil shielding layer 4, a metal mesh layer, or a corrugated metal shielding layer 4.

[0060] In one embodiment, the thickness of the sheath layer 5 is 1-3 mm, and its material includes low smoke halogen-free polyolefin (LSZH) that meets the flame retardant rating in GB / T 17737.1.

[0061] In one embodiment, the inner diameter of the inner conductor 2 is adapted to single-mode optical fiber, multimode optical fiber, fiber optic bundle tube, semi-finished optical cable or finished optical cable, and is made into a spiral protective structure by precision welding process and corrugation to protect the internal optical fiber 1, while shielding the signal from affecting the signal transmission of optical fiber 1.

[0062] The composite RF coaxial cable of this invention is essentially the same as traditional RF coaxial cables in terms of installation and use. Because its structural dimensions are identical to traditional RF coaxial cables, it can be directly applied to existing communication equipment and lines. During installation, simply connect both ends of the cable to the corresponding equipment interfaces, ensuring a secure connection and good contact.

[0063] This composite RF coaxial cable can transmit optical waves and RF signals simultaneously without interference between them. Optical waves are transmitted through the optical fiber, while RF signals are transmitted through the space between the inner conductor 2 and the shielding layer 4 of the RF coaxial cable. This achieves efficient and stable transmission of multiple signals, meeting the needs of modern communication systems for simultaneous transmission of various signals.

[0064] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although this utility model has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A composite radio frequency coaxial cable, characterized in that, include: The inner conductor (2) has a helical tubular structure; An optical fiber (1) is embedded inside the inner conductor (2), and optical fiber filling grease is filled between the optical fiber (1) and the inner conductor (2). An insulating layer (3) is disposed on the outside of the inner conductor (2); A shielding layer (4) is disposed on the outside of the insulating layer (3); A sheath layer (5) is disposed on the outside of the shielding layer (4).

2. The composite radio frequency coaxial cable according to claim 1, characterized in that, The inner conductor (2) is a spiral tubular structure formed by welding metal strips and then rolling.

3. A composite radio frequency coaxial cable according to claim 2, characterized in that, The metal strip is made of one of the following materials: copper, aluminum, aluminum alloy, or copper alloy.

4. A composite radio frequency coaxial cable according to claim 2 or 3, characterized in that, The thickness of the metal strip is 0.1-0.3 mm.

5. A composite radio frequency coaxial cable according to claim 4, characterized in that, The inner conductor (2) has a groove pitch of 3-10 mm and a groove peak and trough tolerance of ±0.5 mm.

6. A composite radio frequency coaxial cable according to claim 1, characterized in that, The gap between the inner diameter of the inner conductor (2) and the outer diameter of the optical fiber (1) is 1-10 mm.

7. A composite radio frequency coaxial cable according to claim 1, characterized in that, The insulation layer (3) has a thickness of 1-10 mm and includes polytetrafluoroethylene, polyethylene or foamed polyethylene.

8. A composite radio frequency coaxial cable according to claim 1, characterized in that, The shielding layer (4) has a shielding efficiency of ≥100dB and includes an aluminum foil shielding layer (4), a copper foil shielding layer (4), a metal mesh layer, or a corrugated metal shielding layer (4).

9. A composite radio frequency coaxial cable according to claim 1, characterized in that, The thickness of the sheath layer (5) is 1-3 mm, and its material includes low-smoke halogen-free polyolefin.

10. A composite radio frequency coaxial cable according to claim 1, characterized in that, The optical fiber (1) includes single-mode optical fiber, multimode optical fiber, optical fiber bundle tube, semi-finished optical cable or finished optical cable.

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