Phase coil

A phase coil was a component of a transporter system.

A parametric scanner was typically used for aligning phase coils. 

In November 2154, the primary phase coil of the personnel transporter of the failed, disabling the transporter system. 

Before 2367, Geordi La Forge had upgraded the phase coils of the USS Enterprise (NCC-1701-D) to fifty-five field densities.