A resonance burst is a powerful energy pulse which has measurably the same effects as an antimatter discharge. Various starship systems, including the main deflector dish and the warp core, can be modified to produce such a burst.
In 2293, Captain Kirk modified the deflector relays aboard the USS Enterprise-B to make it possible for the ship to fire a resonance burst from the ship's deflector. The burst simulated an antimatter discharge, disrupting a powerful gravimetric field emanating from an energy ribbon in which the Enterprise had become trapped. (Star Trek Generations)
In 2372, B'Elanna Torres was able to modify the USS Voyager's warp core to produce a resonance burst, in an effort to block a psionic field being generated by the Botha. The procedure involved sequencing the magnetic plasma constriction to open a symmetrical warp field. The plasma constriction was set to a temperature of three million Kelvin, a temperature high enough to emit the resonance burst, but not so high as to irradiate the ship. (VOY: "Persistence of Vision")