The wave impedance

Wave impedance

The impedance is a quantity that represents the ratio of electrical to magnetic waves of a data line. The characteristic impedance is of decisive importance for the compatibility of individual components of a data transmission system. All elements of a data link must have the same characteristic impedance (e.g. transmitter output, connector, cable, receiver input). The characteristic impedance is calculated by the inner diameter of the outer conductor, the outer diameter of the inner conductor and the dielectric constant of the insulation.

Common coaxial cables have 50Ohm (50R) or 75Ohm (75R) for video technology.