Well seeing how no one else answered....I dunno. What do the Phase Cannons look like when firing? I only catch the beams, and the Waves. (and the things that causes Splash damage, lol)
If I remember correctly, it also has blueish pulse guns firing from the back side of the ship. My guess is that those huge multihead pulsegunlike things are named phase missiles, as those were the phase cannons previously I think.
Or I am totally wrong, this is just my guess.