RU2610900C2 - Coaxial cable with nanotube insulation - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering and can be used in designs of coaxial communication cables. In a coaxial cable with a nanotube insulation having central metal conductor (1), polymer insulation layer (2) located on it and external metal conductor (3), the polymer insulation of which is made of n polymer layers of nanotubes (4, 5, 6), herewith each layer of the polymer insulation is characterized by a different diameter of nanotubes.

EFFECT: invention provides designing coaxial cables with an insulating material for any dimensions of coaxial pairs with a required low value of relative dielectric permeability.

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Description

Technical field

The invention relates to the field of electrical engineering and can be used in the construction of coaxial communication cables.

State of the art

There are known designs of coaxial cable containing a central copper conductor and an external copper conductor with insulation between them in the form of a solid monolithic, tape and two-layer, porous, cord-tubular, slotted, cord, washer and cap (D.Ya. Galperovich, A.A. Pavlov, NN Khrenkov. Radio-frequency cables. Energoatomizdat, M., 1990, Fig. 1.7 p. 15).

The disadvantage of these structures is the difficulty of obtaining a low value of relative permittivity for various sizes of coaxial pairs.

A known construction of a coaxial signal cable with composite porous insulation, including fluorocorbate polymer. The electrical central conductor is surrounded by a tape obtomat made of porous polytetrafluoroethylene, on which another layer of a similar material is not laid. On top of this porous layer, a metallized polymer tape is then applied around which a drain wire is wound, and a protective sheath of thermoplastic material is still applied on top (U.S. Patent 5210377, MKI H01B 11/18 Kennedy Fransis Hard., Hardie Willian G., Hegenbarth Jack J., WL Gore and Associates Coaxial electric signal cable Having a composite porous insulation. No. 827309. 3Apr. 29.01.92 Pub. 11.05.93 NKI 174/107).

The disadvantage of this design is the complexity of the presented three-layer insulation, which does not allow to obtain a small value of the relative dielectric constant.

The closest in technical essence is a coaxial cable containing a central metal conductor, one layer of porous polymer insulation located on it and an external metal conductor, n-1 layers of porous polymer insulation are additionally introduced into the structure, each of the layers of porous polymer insulation is perforated throughout length with different perforation steps in each layer and different sizes of perforation holes in each layer (RF patent IPC H01B 11/18 No. 2397564. Coaxial communication cable. Portnov E. L. Publish. 08/20/10. Bull. No. 23).

The disadvantage of this coaxial cable is the high value of the relative permittivity for any size of coaxial pairs.

SUMMARY OF THE INVENTION

The objective to which this technical solution is directed is to create a coaxial cable design that allows obtaining the required low value of relative permittivity from the insulation materials used in the construction of coaxial cables of insulating materials for any sizes of coaxial pairs.

To solve this problem, in a coaxial cable containing a central conductor, polymer insulation and an external conductor, polymer insulation is made of n layers of nanotubes, each polymer insulation layer having a different nanotube diameter.

List of drawings

In FIG. 1 shows the design of a coaxial cable.

The structure comprises a central conductor 1, a polymer insulation layer 2 located on it, and an external conductor 3, n a layer of polymer insulation nanotubes 4, 5, 6, each of the n layers of polymer insulation containing nanotubes of different diameters.

The implementation of the invention

To obtain the optimal sizes of coaxial pairs with the desired value of wave impedance with a minimum value of the attenuation coefficient, the relations between the inner diameter of the outer conductor and the diameter of the central conductor are selected: 3.6 for copper conductors, other values for other conductor materials. When transmitting maximum power over a coaxial pair, the ratios between the diameters of the coaxial conductors will be completely different, also these ratios will take other values at the maximum breakdown voltage.

In all cases, it is advisable that the relative dielectric constant of the insulation be close to unity (for example, 1.1; 1.2, etc.). Therefore, the number of layers n in each optimal case is limited by the ratio of the diameters of the conductors, the value of the wave resistance and the value of the relative permittivity. The choice of the thickness of each layer n is associated with the choice of the required value of wave impedance.

The choice of different layers of nanotubes and different sizes of nanotubes of different diameters in each layer will make it possible to more accurately select the necessary values of the relative permittivity of the polymer insulation of the coaxial pair and, therefore, to more accurately obtain the wave impedance of the coaxial pair.

Claims (1)

A coaxial cable with nanotube insulation, containing a central conductor, one polymer insulation layer located on it, and an external conductor, characterized in that the insulation consists of n polymer layers of nanotubes, each polymer insulation layer having a different nanotube diameter.

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