Patent ID: 8455761

Claim:
A coaxial cable comprising: an insulator having void portions continuing in a longitudinal direction; a central conductor covered with the insulator; and an outer conductor arranged on an outer circumference of the insulator, wherein: each of the void portions is formed to have a circular or elliptical cross section, the void portions are evenly arranged in the insulator in a set of eight, in a cross section perpendicular to the longitudinal direction of the coaxial cable, a void ratio of each of the void portions is 6.8% or less, and a void ratio of the entire void portions is 43% to 54%, where the void ratio of the entire void portions is a proportion of the void portions to a sum of a total area of all the void portions and an area of the insulator, and a ratio of a diameter of the insulator to a diameter of the central conductor is 2.4 to 2.7.