Basic Information
In science fiction, the term Ultrawave or Hyperwave denotes a form or energy or particle that travels faster than light and can thus facilitate FTL Communication, specifically FTL Radio. Ultrawaves may or may not share properties with Tachyons and/or Electromagentism. They may or may not travel through Hyperspace or Subspace.
The term was introduced in the Lensman series by E.E. Smith, used in Isaac Asimov's Foundation series, and mentioned in Star Trek once or twice.
Logically, in the same way that the normal energies of the Electromagnetic Spectrum can be concentrated and focused to create a Laser, one can conclude there may be a way to use Ultrawaves as an FTL Weapon.