Velocity factor

The velocity factor ( sales area) is the ratio of the speed signal on a line to the speed of light. It corresponds to the refractive index of homogeneous optical propagation media, but does not only depend on the material, but also on the geometry of the cross-section.

The sales promotion can be determined experimentally by time domain reflectometry and is taken into account, for example, in the implementation of management circles. Some values ​​for high frequency cables are:

Higher propagation speeds ( and lower losses ) can be achieved in coaxial cables whose inner conductor is held by a foamed dielectric in place. Meanwhile, lower permittivity decreases the capacitance per unit length of the line. For delay lines with very low propagation speed of highly permeable material used.