Abstract: The invention relates to a low loss foam composition and cable, such as a coaxial cable. The foam composition is formed by heating an olefinic polymer, such as a high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, or a combination thereof, into a molten state composition, optionally with a nucleating agent. The molten mixture is extruded under pressure through a die with a blowing agent comprising an atmospheric gas, such as carbon dioxide, nitrogen or air, and a co-blowing agent selected from hydrofluorocarbons, hydrochlorofluorocarbons, or perfluoro compounds, such as HFC-134a. The cable is formed by extruding the foam composition onto a signal carrying conductor and sheathing the foam-coated signal carrying conductor in an appropriate conducting shield.

Abstract: The invention relates to a low loss foam composition and cable, such as a coaxial cable. The foam composition is formed by heating an olefinic polymer, such as a high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, or a combination thereof, into a molten state composition, optionally with a nucleating agent. The molten mixture is extruded under pressure through a die with a blowing agent comprising an atmospheric gas, such as carbon dioxide, nitrogen or air, and a co-blowing agent selected from hydrofluorocarbons, hydrochlorofluorocarbons, or perfluoro compounds, such as HFC-134a. The cable is formed by extruding the foam composition onto a signal carrying conductor and sheathing the foam-coated signal carrying conductor in an appropriate conducting shield.

Abstract: An RF coaxial cable with clad conductors includes an inner tubular conductor having a first base layer formed of a relatively higher conductivity material, and a first bulk layer formed of a relatively lower conductivity material. The first base layer of higher conductivity material extends over an area greater than an area of the first bulk layer to form first margin regions composed of only the higher conductivity material. The first margin regions of the first base layer of the higher conductivity material are joined together to form the inner tubular conductor with only the first margin regions of the higher conductivity material being joined. Also included is a dielectric material surrounding the inner conductor, an outer tubular conductor formed in the same manner as the inner conductor.

Abstract: A corrugated coaxial cable including a core with at least one inner conductor and a highly expanded polymeric foam dielectric surrounding the inner conductor. This coaxial cable has a corrugated outer conductor closely encapsulating the foam dielectric. The corrugated coax cable is dimensioned to provide the cable with a velocity of propagation of greater than 90% of the speed of light.

Abstract: An RF coaxial cable with clad conductors includes an inner tubular conductor having a first base layer formed of a relatively higher conductivity material, and a first bulk layer formed of a relatively lower conductivity material. The first base layer of higher conductivity material extends over an area greater than an area of the first bulk layer to form first margin regions composed of only the higher conductivity material. The first margin regions of the first base layer of the higher conductivity material are joined together to form the inner tubular conductor with only the first margin regions of the higher conductivity material being joined. Also included is a dielectric material surrounding the inner conductor, an outer tubular conductor formed in the same manner as the inner conductor.

Abstract: A corrugated coaxial cable including a core with at least one inner conductor and a highly expanded polymeric foam dielectric surrounding the inner conductor. This coaxial cable has a corrugated outer conductor closely encapsulating the foam dielectric. The corrugated coax cable has a velocity of propagation of greater than 90% of the speed of light, resulting in improved signal propagation characteristics, especially in attenuation, while still maintaining the high flexibility and bending properties which are characteristic of corrugated coaxial cables designs.

Abstract: A fluid detection system includes a cable which is capable of being dried easily after coming into contact with the fluid being detected and displays a measurable change in characteristic impedance immediately upon contact with the fluid. The cable comprises an inner conductor and a cylindrical outer conductor disposed in a substantially parallel and coaxial relationship with each other with a dielectric detection layer coaxially disposed between the inner and outer conductors. The outer conductor is of an open braided construction which permits easy passage therethrough of the fluid to be detected. The detection layer comprises a pair of solid dielectric elements stranded around the inner conductor in a double helical configuration and defining an air gap between the two conductors which is adapted to retain the fluid so as to measurably change the characteristic impedance of the cable.