This chapter presents the performance of RF coaxial cables that are typically used for signal cabling inside a radio system. Particularly, RF coaxial cables are used for connecting radio transmitters and receivers to antennas, as well as for interconnecting RF equipment of the radio system. Additionally, effective methods for impedance matching between radio stations (transmitters and receivers) and their antennas are considered in this chapter. Additionally, the performance of twisted-pair signal lines (unshielded and shielded), which are used for connecting IT equipment to radio systems, is considered in this chapter. This is considered because twisted-pair lines can be affected by EMI and radio emissions from radio system. Finally, the performances of the optical cables and electronic–optical transceivers are considered in terms of EMI.