An underground radio communication technology using a specially constructed coaxial cable that intentionally radiates and receives RF signal along its entire length, run through mine tunnels and amplified at intervals to provide continuous two-way radio coverage where conventional wireless propagation is blocked by tunnel geometry and rock.

Key Points

The radiating cable itself functions as a continuous, distributed antenna along its full run, rather than relying on discrete antenna points as a conventional wireless system would
Amplifiers and repeaters are spaced at intervals along the cable to counteract signal attenuation, since a leaky feeder's coverage is fundamentally bounded by cable run length and amplification
Provides reliable coverage precisely where conventional over-the-air wireless signals cannot propagate — around tunnel bends, through rock, and along the twisting geometry typical of underground mine workings
One of the longest-established underground mine communication technologies, predating modern underground LTE and other wireless alternatives by decades
Physical cable damage — a real operational risk in an active mining environment with heavy equipment and blasting — can take out coverage along an entire cable segment at once, a distinct failure mode from a conventional wireless system's more localized coverage loss

Concept

Unlike a conventional radio system, where a signal radiates outward from a discrete antenna point and must then propagate through open space to reach a receiver, a leaky feeder cable is deliberately engineered with gaps or slots in its outer shielding that let RF energy leak out — and be received back in — continuously along its entire run. Run through a mine's tunnel network and periodically amplified to counteract cable attenuation, this gives a device anywhere along the cable's length a usable radio link, regardless of tunnel bends or rock that would otherwise block a conventional wireless signal.

Explainer

The engineering tradeoff a leaky feeder system makes is coverage reliability along a known, fixed path in exchange for infrastructure dependency and physical vulnerability — because coverage follows the cable run exactly, a leaky feeder provides highly predictable, reliable connectivity along established tunnels, but that same design means physical damage to the cable (from blasting, heavy equipment, or rockfall) can silence coverage along an entire affected segment simultaneously, a very different failure mode than a conventional wireless network's more localized, single-access-point outage. This physical fragility, combined with the bandwidth limitations inherent to a coaxial cable system relative to modern wireless alternatives, is why many mining operations are progressively supplementing or replacing leaky feeder infrastructure with underground LTE and other wireless systems where the higher capital cost is justified by the application's bandwidth needs, while leaky feeder often remains in place as a reliable, well-understood baseline voice and low-bandwidth data layer. For CE mining operations, leaky feeder's decades of operational maturity and its specific resilience to the tunnel-geometry challenges that block conventional wireless make it a durable baseline communication layer even as newer wireless technologies are layered alongside it for higher-bandwidth applications.