The phased cloak was an illegal and highly unstable technology (see what happened to the test ship) that the crew on the USS Enterprise-D used as last resort to get out of the asteroid. They then beamed it out in space and destroyed it in front of the Romulan ship as soon as they got out.
Only the Klingons and Romulans where allowed to use cloaks due to a treaty that was signed by the Federation. The Defiant goes against this treaty, but then again I haven't watched DS9 so I don't know what happened that allowed the Federation to have a cloaking ship.
It was not "beamed out into space" You can check for yourself using this link. Star Trek