Patent ID: 6963032

Claim:
A foamed coaxial cable with high precision comprising: an internal conductor having a plurality of electrically conductive wires twisted with each other; a foamed insulator with a low dielectric constant made of a porous tape body formed on an outer periphery of the internal conductor; an external conductor made of a number of electrically conductive thin wires braided on an outer periphery of the foamed insulator; and an outer sheath made of resin having heat resistance formed on an outer periphery of the external conductor, wherein the precision of external diameter of the internal conductor is 4/1000 mm or less; the precision of external diameter size of the foamed insulator is ±0.02 mm, the precision of external diameter size of the external conductor is ±2% of the center value of the external diameter of the external conductor, the external conductor is formed in a completely circular-shape; and the precision of the characteristic impedance value between the internal conductor and the external conductor having the foamed insulator interposed therebetween is ±1 Ω.