Adapted to the structure of a coaxial cable, the coaxial connectors also protect the inner conductor from electromagnetic influences by surrounding it with an insulating layer. The so-called dielectric is often made of plastic such as polyethylene and ensures both shielding and capacitive behavior.

In addition, both the characteristic impedance and the impedance influence the structure of a coaxial connector. The line characteristic impedance is mainly influenced by the properties of the dielectric and describes the relationship between a current moving in the same direction and moving voltage waves. The characteristic impedance of the cable depends on the frequency, while the cable length has no influence on it.

The impedance is usually 50 ohms in the high-frequency range and 75 ohms for audio and television technology. The impedance results from the ohmic resistance and the reactance.The main advantages of coaxial cables are their high transmission speed and simple connection technology.