Co-axial Cables

Additional Details

As the frequency of signals are in Megahertz the mutual capacitance between two conductors should be minimum to reduce the loss of signal .Polyethylene with dielectric constant of 2.3 is the most ideally suited for insulation for these cables. Air has got the minimum dielectric constant of 1.0 and efforts are made to approach it by making the Polyethylene porous. Earlier chemical foaming was used, where the chemicals added in Polyethylene evaporated out during coating due to high temp, leaving the insulation porous. To day Nitrogen is injected in molten Polyethylene to form foam Polyethylene which has got dielectric constant of 1.70.