RU2731624C1 - Symmetric four-pair cable with film-nano-tube insulation of cores - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering and can be used in makeups of symmetric communication cables within a shared network or structured cable systems. In four-pair cable containing cores in film-polymer insulation, twisted into pairs with different pitching strands into common layer, with outer polymer shell isolation of each core. Outer polymer shell of each core is made in the form of nanotubes of the same size over the entire cross-section of each core, wherein a part of the nanotubes is perforated. Outer film is in contact with nanotubular insulation of each core throughout the section; each core along the entire length of the balanced cable.

EFFECT: invention provides creation of such design of symmetric four-pair cable, which allows to reduce relative dielectric permeability of cable cores insulation, to reduce capacitance of steam and, hence, dielectric losses and capacitive component of influence between pairs.

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Description

Technology area

The invention relates to the field of electrical engineering and can be used in the construction of symmetrical communication cables for public networks and structured cable systems.

State of the art

Known design of a four-pair cable containing copper conductors in dielectric insulation, twisted into pairs with different pitch in a common outer dielectric sheath ("Structured cable systems" AB Semenov, SK Strizhakov, IR Suncheley; DMK publishing house; M. 2002, 4th edition, p. 109, fig. 3.4 and 3.5). The disadvantage of this design is the rather high value of the relative dielectric constant of the cable core insulation.

Depending on the category, various types of cable core insulation are used: for Category 1 cable cores, polyethylene with a relative dielectric constant of 2.3 is used as core insulation; for cables of category 3, a dielectric material with a relative dielectric constant of 2.3 is used; for cables of category 5, cellular polyethylene with a sheath is used as core insulation - film-porous polyethylene with a relative dielectric constant of 2.0; For cables of category 6, Teflon core insulation with a relative dielectric constant of 2.0 is used.

The known design of a four-pair cable, consisting of two fours, where each four is twisted from two pairs, with a film-porous insulation of cores and an outer polymer sheath ("Structured cable systems" AB Semenov, SK Strizhakov, I.R. . Suncheley; DMK publishing house; M. 2002, 4th edition, p. 106, fig. 3.2b). The disadvantage of this design is also the high value of the relative dielectric constant of the core insulation.

The closest in technical essence to the claimed invention is the construction of a four-pair cable described in the brochure of Teldor, Wires and Cables, Russia Ltd. 2006, 223 c., P. 35 (website: www.teldor.com.). The cable consists of four unshielded twisted (twisted) pairs, twisted together, protected by a PVC sheath for internal fixed installation; core diameter 0.51 mm, polyolefin insulation (film-porous film insulation), outer diameter of insulated core 0.9 mm; outer cable diameter 5.0 mm. Considering the maximum signal propagation speed equal to 0.7 times the speed of light, the relative dielectric constant of the core insulation is 2.0, which is also a high value and is the main disadvantage of this cable.

The essence of the invention

The task for the implementation of which this technical solution is directed is the creation of such a structure of a symmetrical four-pair cable, which allows to reduce the relative dielectric constant of the cable core insulation, to reduce the capacitance of the pairs and, consequently, the dielectric losses and the capacitive component of the influence between pairs.

To solve this problem, in a four-pair cable containing cores in film-polymer insulation, twisted into pairs with different twisting steps into a common layer, with an outer polymer sheath, the insulation of each core is made in the form of nanotubes of the same size along the entire cross section of each core, and some of the nanotubes are perforated , and the outer film is in contact with the nanotube insulation of each core along the entire cross section of each core along the entire length of the symmetrical cable.

List of figures

FIG. 1 shows the structure of a symmetrical four-pair cable with film-nanotube insulation of cores. The cable contains: symmetrical pairs - 1, cores - 2, nanotube core insulation - 3, outer core insulation film - 4, in contact with the nanotubular insulation, outer polymer cable sheath - 5.

FIG. 2 shows an enlarged design of an insulated core of a symmetrical cable with film-nanotubular insulation of cores. It contains: core - 2, nanotubes along the entire cross section of the core - 6, perforated nanotubes - 7, outer insulation film - 4 in contact with the nanotubes along the entire cross section of the core along the entire length of the symmetrical cable.

Implementation of the invention

The proposed design of a symmetrical four-pair cable with film-nanotube insulation of cores contains symmetrical pairs 1, cores 2, nanotube insulation of core 3, outer film of core insulation 4, outer polymer sheath of the cable - 5. Insulation 3 of each core 2 is made in the form of nanotubes 6, 7 along the entire section of each core 2. Outer film 4 is in contact with the nanotube insulation 3 of each core 2 along the entire cross section of each core and along the entire length of the symmetrical cable, with some of the nanotubes being perforated 7.

Thanks to the claimed design, the relative dielectric constant of the core insulation is significantly reduced due to the nanotubes, inside which the relative dielectric constant is 1.0 (the relative dielectric constant of the air is 1). Depending on the number of nanotubes and perforated nanotubes, the relative permittivity can be changed over a fairly wide range, decreasing the insulation thickness and decreasing dielectric losses. The dielectric constant of the dielectric material is 2.3, taking into account the film-nanotube insulation when filling through holes of the nanotubes and contacting the veins in the volume of 100% of the entire volume of the conductor insulation, we obtain the relative dielectric constant of the entire conductor insulation equal to 1.9. As a result, the attenuation coefficient decreases due to a decrease in losses in the insulation of the conductors, the wave resistance and the capacitive component of the influence between pairs, and due to a decrease in the thickness of the insulation and, therefore, the distance between the conductors in a pair, the inductance of the circuit also decreases.

Claims (1)

Symmetrical four-pair cable with film-nanotube insulation of cores, containing cores in film-polymer insulation, twisted into pairs with different twisting steps into a common layer with an outer polymer sheath, characterized in that the insulation of each core is made in the form of nanotubes of the same size along the entire cross-section of each core, and part nanotubes are perforated along the entire cross-section of the core along the entire length of the symmetrical cable, and the outer film contacts the nanotube insulation of each core along the entire cross-section of each core along the entire length of the symmetrical cable.

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