An antimatter injector is a device in antimatter containment which precisely compresses and streams antimatter into the form which enters the dilithium articulation frame in a starship's warp core. (ENT: "Acquisition")
During the 2150s, Andorian battle cruisers were fitted with antimatter injectors that used variable-compression nozzles. At the time, the Andorians considered the technology as "very sophisticated," and knowledge about them as "rather sensitive." During the Xindi mission, Trip Tucker received an antimatter injector from Shran, as a favor, because, according to Tucker, "one of those injectors would work wonders for our engines." (ENT: "Proving Ground")
In 2374, a lone member of Species 8472 gained access to Main Engineering on the USS Voyager through the antimatter injector port. It attacked the engineering crew, though it did not damage the ship. (VOY: "Prey")
In late 2375, when the USS Defiant was about to leave Deep Space 9 for the Chin'toka system, Colonel Kira Nerys opened the ship's antimatter injector ports. (DS9: "The Changing Face of Evil")
- Unlike the deuterium injectors, the antimatter injectors deal with very small amounts. (citation needed • edit)