leaky feeder signal transmission
Leaky waveguides are coaxial cables whose outer conductor is slit at regular intervals. The spacing of the slit openings is determined by the radiated wavelength. Waves can emerge from these slot openings and propagate.
Since antennas, resonant circuits and coaxial cables are subject to the same high- frequency laws, the leaky waveguide acts like an antenna and can be used to radiate the microwaves. In a normal coaxial cable, the outer conductor is not only shielding, but determines the frequency response.
Leaky waveguides are used in tunnels where they ensure interference-free broadcast reception, and also in office buildings and industrial plants as antennas for WLANs. There, they ensure flawless WLAN communication even in heavily impaired construction environments where no cable can be laid.