Broad band radiation type leak coaxial cable for subway and its production method

Abstract

The invention relates to a broadband radial pattern leaky coaxial cable used for subway and a manufacturing method thereof, and the leaky coaxial cable has the double functions of transmission line of information and duplexer. The structure of the leaky coaxial cable consists of an inner conductor, an insulation layer, an outer conductor and a jacket, wherein, the inner conductor is externally covered with the insulation layer which is externally covered with the outer conductor that is externally sheathed with the jacket, and the insulation layer that covers on the surface of the inner conductor adopts nitrogen or carbon dioxide physical foam to form a foamed polyethylene insulation layer; cambered slotted holes are opened on a clutch gold belt of the outer conductor covered outside the insulation layer. The manufacturing method comprises the steps: (1) a spiral wrinkle inner conductor is manufactured by longitudinal covering welding and embossing by using a copper strip; (2) the nitrogen or the carbon dioxide are adopted to be injected into the smelted polyvinyl plastics, and then the physical foamed polyethylene insulation layer is formed on the surface of the inner conductor by extrusion and cladding; (3) the slotted holes broken out by the clutch gold belt of the outer conductor are the cambered slotted holes; (4) the clutch gold belt of the outer conductor is covered on the insulation layer longitudinally, and the surface of the clutch gold belt of the outer conductor is crowded and covered with the jacket.

Description

technical field

[0001] The invention relates to a broadband radiating leaky coaxial cable for subways and a manufacturing method thereof, which has dual functions of an information transmission line and a transmitting and receiving antenna. It is specially used in subway tunnel wireless coverage systems such as Tetra, public security fire protection, GSM, TD-SCDMA, etc. Background technique

[0002] After more than 10 years of development of mobile communication, for the majority of users, there is an urgent need for the entire mobile communication network to achieve high-speed seamless coverage anytime, anywhere. With the vigorous promotion of information communication and multimedia, people have put forward higher requirements for services, hoping to have a variety of service options, and the expectations for high-speed data service mobility are also getting higher and higher. The function of 3G lies in high-speed data and The application of multimedia services, while hig...

Examples

Embodiment 1

[0026] 1. A copper strip with a thickness of 0.3mm is selected and welded longitudinally to form a copper tube, and then the corrugated inner conductor 1 with an outer diameter of Φ17.4±0.1mm is manufactured by embossing;

[0027] 2. Nitrogen or carbon dioxide with a purity of 99.99% is injected into the molten polyethylene insulator through a high pressure of 350bar, fully mixed at a high temperature of 180°C, and physically foamed, and then extruded and coated on the surface of the inner conductor 1 The insulating layer 2 is formed, the insulating layer 1 has uniform foaming pores, and the foaming pores are closed to each other, the outer diameter of the foamed cable core is uniform and consistent, the foaming degree reaches 80%, and the capacitance is stably controlled within the range of 77±1pF / m Inside;

[0028] 3. The outer conductor 4 uses a copper foil strip. First, the copper foil strip is programmed and continuously automatically controlled on a special punching mach...

Embodiment 2

[0031] 1. A copper strip with a thickness of 0.35mm is selected and welded longitudinally to form a copper pipe embossed and integrated to manufacture a spiral corrugated inner conductor 1 with an outer diameter of Φ17.4±0.1mm;

[0032] 2. Nitrogen or carbon dioxide with a purity of 99.99% is injected into the molten polyethylene insulator through a high pressure of 350bar, fully mixed at a high temperature of 190°C, and physically foamed, and then extruded and coated on the surface of the inner conductor 1 The insulating layer 2 is formed, the insulating layer 1 has uniform foaming pores, and the foaming pores are closed to each other, the outer diameter of the foamed cable core is uniform and consistent, the foaming degree reaches 80%, and the capacitance is stably controlled within the range of 77±1pF / m Inside;

[0033] 3. The outer conductor 4 uses a copper foil strip. First, the copper foil strip is programmed and continuously automatically controlled on a special punchin...

Embodiment 3

[0036] 1. A copper strip with a thickness of 0.4mm is selected and welded longitudinally to form a copper tube embossed and integrated to manufacture a spiral corrugated inner conductor 1 with an outer diameter of Φ17.4±0.1mm;

[0037]2. Nitrogen or carbon dioxide with a purity of 99.99% is injected into the molten polyethylene insulator through a high pressure of 350bar, fully mixed at a high temperature of 200°C, and physically foamed, and then extruded and coated on the surface of the inner conductor 1 The insulating layer 2 is formed, the insulating layer 1 has uniform foaming pores, and the foaming pores are closed to each other, the outer diameter of the foamed cable core is uniform and consistent, the foaming degree reaches 80%, and the capacitance is stably controlled within the range of 77±1pF / m Inside;

[0038] 3. The outer conductor 4 uses a copper foil strip. First, the copper foil strip is programmed and continuously automatically controlled on a special punching ...

technical field

[0001] The invention relates to a broadband radiating leaky coaxial cable for subways and a manufacturing method thereof, which has dual functions of an information transmission line and a transmitting and receiving antenna. It is specially used in subway tunnel wireless coverage systems such as Tetra, public security fire protection, GSM, TD-SCDMA, etc. Background technique

[0002] After more than 10 years of development of mobile communication, for the majority of users, there is an urgent need for the entire mobile communication network to achieve high-speed seamless coverage anytime, anywhere. With the vigorous promotion of information communication and multimedia, people have put forward higher requirements for services, hoping to have a variety of service options, and the expectations for high-speed data service mobility are also getting higher and higher. The function of 3G lies in high-speed data and The application of multimedia services, while hig...

Examples

Embodiment 1

[0026] 1. A copper strip with a thickness of 0.3mm is selected and welded longitudinally to form a copper tube, and then the corrugated inner conductor 1 with an outer diameter of Φ17.4±0.1mm is manufactured by embossing;

[0027] 2. Nitrogen or carbon dioxide with a purity of 99.99% is injected into the molten polyethylene insulator through a high pressure of 350bar, fully mixed at a high temperature of 180°C, and physically foamed, and then extruded and coated on the surface of the inner conductor 1 The insulating layer 2 is formed, the insulating layer 1 has uniform foaming pores, and the foaming pores are closed to each other, the outer diameter of the foamed cable core is uniform and consistent, the foaming degree reaches 80%, and the capacitance is stably controlled within the range of 77±1pF / m Inside;

[0028] 3. The outer conductor 4 uses a copper foil strip. First, the copper foil strip is programmed and continuously automatically controlled on a special punching mach...

Embodiment 2

[0031] 1. A copper strip with a thickness of 0.35mm is selected and welded longitudinally to form a copper pipe embossed and integrated to manufacture a spiral corrugated inner conductor 1 with an outer diameter of Φ17.4±0.1mm;

[0032] 2. Nitrogen or carbon dioxide with a purity of 99.99% is injected into the molten polyethylene insulator through a high pressure of 350bar, fully mixed at a high temperature of 190°C, and physically foamed, and then extruded and coated on the surface of the inner conductor 1 The insulating layer 2 is formed, the insulating layer 1 has uniform foaming pores, and the foaming pores are closed to each other, the outer diameter of the foamed cable core is uniform and consistent, the foaming degree reaches 80%, and the capacitance is stably controlled within the range of 77±1pF / m Inside;

[0033] 3. The outer conductor 4 uses a copper foil strip. First, the copper foil strip is programmed and continuously automatically controlled on a special punchin...

Embodiment 3

[0036] 1. A copper strip with a thickness of 0.4mm is selected and welded longitudinally to form a copper tube embossed and integrated to manufacture a spiral corrugated inner conductor 1 with an outer diameter of Φ17.4±0.1mm;

[0037]2. Nitrogen or carbon dioxide with a purity of 99.99% is injected into the molten polyethylene insulator through a high pressure of 350bar, fully mixed at a high temperature of 200°C, and physically foamed, and then extruded and coated on the surface of the inner conductor 1 The insulating layer 2 is formed, the insulating layer 1 has uniform foaming pores, and the foaming pores are closed to each other, the outer diameter of the foamed cable core is uniform and consistent, the foaming degree reaches 80%, and the capacitance is stably controlled within the range of 77±1pF / m Inside;

[0038] 3. The outer conductor 4 uses a copper foil strip. First, the copper foil strip is programmed and continuously automatically controlled on a special punching ...

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