A leaky feeder is an antenna, also known as a radiating cable, and is a specialised type of coaxial cable used for communication and signal distribution in environments where traditional antennas may not be suitable. It is commonly employed in underground mines, tunnels, and other enclosed spaces where radio signals struggle to propagate due to the presence of obstacles or shielding materials.
The leaky feeder antenna consists of a coaxial cable with specific design modifications that allow it to radiate or leak radio signals along its entire length. Unlike standard coaxial cables that aim to minimize signal leakage, leaky feeder cables are intentionally designed to release signals at controlled points along the cable’s outer conductor.
The cable is usually installed along the desired coverage area, such as tunnels or underground corridors, and its radiating characteristic ensures that the radio signals leak out along its length, providing continuous coverage. This leakage occurs through small slots, gaps, or periodic discontinuities deliberately introduced in the cable’s outer conductor.
Leaky feeder systems are often used in conjunction with two-way radios or other wireless communication devices. The signals transmitted from the base station or a central source are coupled into the leaky feeder cable, and they propagate along its length, radiating out into the surrounding area through intentional leaks. This allows personnel within the coverage area to communicate wirelessly using handheld radios or other compatible devices.
Leaky feeder antennas offer several advantages in challenging environments. They can overcome signal blockages caused by obstacles like walls, rocks, or equipment. Additionally, they provide a robust and reliable means of communication in areas where other wireless technologies may fail.
It’s worth noting that leaky feeder systems may require signal amplifiers or repeaters at specific intervals to maintain signal strength over long distances or in areas with significant attenuation. These amplifiers or repeaters help compensate for the signal loss that naturally occurs as the radio waves propagate through the cable and surroundings.
Overall, leaky feeder antennas provide an effective solution for maintaining continuous communication and signal coverage in environments where traditional antennas face significant challenges.