US Patent 10217548 Coaxial cable

A coaxial cable includes a conductor, an insulation layer provided around the conductor, a shield layer provided around the insulation layer, and a sheath provided around the shield layer. The insulation layer includes a first insulation layer, a second insulation layer and a third insulation layer that are arranged in this order from a conductor side. The first insulation layer includes a non-solid extruded layer. The second layer includes a foamed layer not adhering to the first insulation layer. The third insulation layer includes a non-foamed layer adhering to the second insulation layer.