Coaxial Cable and Method of Construction Thereof

Abstract

A coaxial cable and method of construction thereof are provided. The coaxial cable includes an elongate central conductive member; a dielectric insulative layer encasing the central conductive member; an outer protective sheath, and a braided EMI shield layer including hybrid yarn sandwiched between the dielectric insulative layer and the outer protective sheath. The hybrid yarn includes an elongate nonconductive filament and an elongate continuous conductive wire filament. The wire filament is interlaced in electrical communication with itself or other wire filaments along a length of the EMI shield layer to provide protection to the central conductive member against at least one of EMI, RFI or ESD. The method includes providing a central conductive member; forming a dielectric insulative layer surrounding the central conductive member; braiding an EMI shield layer including hybrid yarn about the insulative layer, and forming an outer protective sheath about the braided EMI shield layer.

What is claimed is: 
     
         1 . A coaxial cable, comprising:
 a central conductive member;   a dielectric insulative layer surrounding said central conductive member;   an outer protective sheath; and   a braided EMI shield layer sandwiched between said dielectric insulative layer and said outer protective sheath, said braided EMI shield layer being braided with hybrid yarn, said hybrid yarn including at least one electrically conductive wire filament twisted or served with at least one nonconductive filament.   
     
     
         2 . The coaxial cable of  claim 1  wherein said braided EMI shield layer is braided entirely with said hybrid yarn. 
     
     
         3 . The coaxial cable of  claim 1  wherein said at least one nonconductive filament provides enhanced elastic spring-back to said braided EMI layer. 
     
     
         4 . The coaxial cable of  claim 1  wherein said at least one nonconductive filament provides enhanced impact-resistance to said braided EMI layer. 
     
     
         5 . The coaxial cable of  claim 1  wherein said outer protective sheath is reduced in thickness relative to an outer sheath of a prior art coaxial cable. 
     
     
         6 . The coaxial cable of  claim 1  wherein the mass of said coaxial cable is reduced relative to the mass of a prior art coaxial cable. 
     
     
         7 . The coaxial cable of  claim 1  wherein at least one of said at least one nonconductive filament is a multifilament. 
     
     
         8 . The coaxial cable of  claim 7  wherein at least one of said at least one nonconductive filament is a monofilament. 
     
     
         9 . A method of constructing a coaxial cable, comprising:
 providing an electrically conductive member;   forming an insulative layer about the electrically conductive member;   braiding a shield layer about the insulative layer;   forming an outer protective sheath about the shield layer; and   further including braiding the shield layer at least in part from hybrid yarn including at least one electrically conductive wire filament twisted or served with at least one nonconductive filament.   
     
     
         10 . The method of  claim 9  further including braiding the shield layer entirely from the hybrid yarn. 
     
     
         11 . The method of  claim 9  further including providing the hybrid yarn having a plurality of nonconductive filaments. 
     
     
         12 . The method of  claim 11  further including providing at least one of the plurality of nonconductive filaments as a multifilament. 
     
     
         13 . The method of  claim 12  further including providing at least one of the plurality of nonconductive filaments as a monofilament. 
     
     
         14 . The method of  claim 9  further including reducing the thickness of the outer protective sheath relative to an outer sheath of a prior art coaxial cable. 
     
     
         15 . The method of  claim 9  further including reducing the total mass of the coaxial cable relative to the mass of a prior art coaxial cable.