Method of making a flexible coaxial cable and resultant cable

Abstract

An improved method for making a flexible coaxial cable having an inner conductor (36) to which a dielectric material is secured to form a dielectric core (30) for the coaxial cable (38), and a flexible outer conductor (50) such as one formed from a strip helically wound conductor (58), employs a solid dielectric starting material (32), such as a spline dielectric or a cylindrical dieletric or an expanded dielectric, which is ccntrollably cut, such as by saw blades (34), using a desired cutting angle (.theta.) and blade width (.alpha.), in order to cut away a predetermined amount of the solid dielectric starting material (32) to provide a shaped dielectric core (30), such as a spiral or helix (30a, 30b), from the solid dielectric starting material (32). The resulting core (30), such as single or double helix (30a, 30b), which has a predetermined pitch which provides a desired predetermined velocity of propagation and impedance for the coaxial cable (38), is inserted into the convoluted outer conductor (50) to produce a fast cable (38) without any locking of the core (30) to the outer conductor (50). However, to provide additional stability to the flexible coaxial cable (38), the core (30) may be locked to the outer conductor (50) by any of numerous locking methods. By calculating in advance the type of cut to be made to the solid dielectric starting material (32) and the amount of dielectric material to be removed, various parameters such as impedance, velocity of propagation or phase length, attenuation, and VSWR, associated with the resulting flexible coaxial cable (38), may be readily controlled.

Dependencies are inferred from the claim text.