A communication cable that has a reduced diameter while ensuring a required magnitude of characteristic impedance. The communication cable contains a twisted pair that contains a pair of insulated wires, twisted with each other and a sheath covering the twisted pair. Each of the insulated wires, contains a conductor that has a tensile strength of 400 MPa or higher and an insulation coating that covers the conductor. The sheath is made of an insulating material having a dielectric tangent of 0.0001 or higher. The communication cable 1 has a characteristic impedance of 10010.

A data communications cable may communicatively coupled two components associated with an information handling system. For example, the data communications cable may include: a differential pair of conductors; a first dielectric material, associated with a first relative permittivity, surrounding the differential pair of conductors; and a second dielectric material, associated with a second relative permittivity, surrounding the first dielectric material. For instance, the first relative permittivity may be greater than the second relative permittivity, and a distance between the differential pair of conductors may vary plus or minus an amount with a length of the data communications cable.

A lead has at least a first and a second conductor. The first conductor and the second conductor each have an electrically conducting core that is surrounded by an electrical insulator. The electrical insulator of the first conductor if formed from a first material, and the electrical insulator of the second conductor is formed from a second material. The first material differs from the second material.

Electrical field grading material which comprises a non-polar elastomeric polymer, a phyllosilicate filler and a carbon black filler, wherein any carbon black filler present in the electric field grading material has a dibutyl phthalate (DBP) absorption number from 30 to 80 ml/100 g. The above material may be used in electrical cable accessories, particularly electrical cable joints or terminations for medium or high voltage cable. The electrical field grading material according to the present invention has varioresistive properties, particularly a significant variation of electrical conductivity as a function of the applied voltage within a reduced voltage range, so as to guarantee a high value of conductivity above a critical value of the electrical field, and therefore to ensure an even distribution of the electrical field lines within the material.

A data transmission cable includes a first wire and a second wire adjacent to each other, each of the first wire and the second wire has a central conductor and a cover layer enclosing the conductor, and the conductor of the first wire has an outer diameter same as the conductor of the second wire. The ratio of the center distance between the first wire and the second wire to the outer diameter of the conductor is in the range of 1.7 to 2.35.

The present invention provides a polypropylene cable protective layer and a preparation method thereof. The polypropylene cable protective layer sequentially includes a dielectric layer, a buffer layer and an insulating layer from the inside to the outside, and the thickness of the dielectric layer accounts for 5%?12% of the thickness of the polypropylene cable protective layer; the thickness of the buffer layer accounts for 17%?25% of the thickness of the polypropylene cable protective layer; the dielectric layer, the buffer layer and the insulating layer are respectively obtained by the wrapping of a polypropylene film A, a polypropylene film B and a polypropylene film C. The polypropylene cable protective layer of the present invention forms a dielectric gradient, and realizes the improvement of the insulation strength and voltage level of the power cable, and the increase of the transmission capability.

An insulated wire having an electrical wire structure capable of reducing an outer diameter while an insulating property and a flame-retardant property are highly kept is provided. In the insulated wire including: a conductor; and a coating layer arranged on an outer periphery of the conductor, the insulated wire has a flame-retardant property that allows the insulated wire to pass a vertical tray flame test (VTFT) on the basis of EN 50266-2-4, has a direct-current stability that allows the insulated wire to pass a direct-current stability test in conformity to EN 50305.6.7, has a diameter of the conductor that is equal to or smaller than 1.25 mm, and has a thickness of the coating layer that is smaller than 0.6 mm.

An insulated wire having an electrical wire structure capable of reducing a diameter while a direct-current stability property and a flame-retardant property are highly kept is provided. In the insulated wire including: a conductor; a flame-retardant semiconductive layer arranged on an outer periphery of the conductor; an insulating layer arranged on an outer periphery of the flame-retardant semiconductive layer; and a flame-retardant layer arranged on an outer periphery of the insulating layer, an oxygen index of the flame-retardant semiconductive layer defined by JIS K7201-2 is larger than 40, and a volume resistivity of the flame-retardant semiconductive layer defined by JIS C2151 is equal to or smaller than 5.010.sup.15 (cm).

A data transmission cable includes a first wire and a second wire adjacent to each other, each of the first wire and the second wire has a central conductor and a cover layer enclosing the conductor, and the conductor of the first wire has an outer diameter same as the conductor of the second wire. The ratio of the center distance between the first wire and the second wire to the outer diameter of the conductor is in the range of 1.7 to 2.35.

A communication cable that has a reduced diameter while ensuring a required magnitude of characteristic impedance. The communication cable contains a twisted pair that contains a pair of insulated wires twisted with each other and a sheath covering the twisted pair. Each of the insulated wires contains a conductor that has a tensile strength of 400 MPa or higher and an insulation coating that covers the conductor. A gap G is formed between the sheath and the insulated wires constituting the twisted pair. The communication cable has a characteristic impedance of 10010 .