Subspace emitter coil
A subspace emitter coil was a component of  Starfleet runabouts in the 2370s.

In 2370, in preparation for his and Major Kira Nerys' mission to Cardassia IV to rescue Li Nalas from the Hutet labor camp, Chief Miles O'Brien installed field buffers around the 's subspace emitter coil to make the runabout look like a Lissepian transport to Cardassian sensors. ()
de:Subraumemitterspule
emitter coil
Propulsion technology