Inverted magnetic pulse
An inverted magnetic pulse was a form of electromagnetic field.

In 2371,  B'Elanna Torres modified the 's main deflector to emit an inverted magnetic pulse in order to nudge a swarm of space-dwelling lifeforms out of the ship's path. However, the pulse caused the creatures to perceive Voyager as a potential mate, and they began to attach to the warp nacelles and drain power. ()

See also
EM power inverter

de: Umgekehrter magnetischer Impuls
Energy