One of the relevant issues by the telecommunication systems in very big indoor/outdoor and high traffic scenarios such as along a very long Tunnel, in big sport stadiums, in big ships, etc., is covering the whole area of the scenario with appropriate transmitting power. To achieve the safe RF coverage in the whole area, many kinds of antennas could not be good candidates. Since they radiate directively and provide depending on the scenario some blind points, they could not be avoided. Repeating the antennas could cause very high costs too and is not a good solution. Nowadays radiating cables as very long leaky wave antennas are already used as one of the best candidates to carry and to provide the acceptable power in the whole area of such scenarios. However radiating cables have their limitations especially at 5G frequency ranges.
The aim of this thesis is the methodical design and implementation of radiating cables providing a safe communication at 5G frequency range (up to 4.2 GHz) in very big indoor/outdoor and high traffic scenarios. Mode analysis of different shaped cross sections of transmission lines, Mode filtering and coaxial mode conversion methods will be investigated. Furthermore, the periodic slots on the cable as coupling elements for different polarisations of propagation will be designed and implemented. As such, methodical elimination of return loss spikes along the periodic radiating cable will be studied particularly.