A phased array antenna for a telecommunications satellite, that is deployable from a retracted condition to a deployed condition when the satellite is on-station, comprising a base member of hexagonal form, and a plurality of deployable antenna panels stacked one on top of the other on the base member in the retracted condition, each antenna panel being connected to a respective side edge region of the base by means of a respective back flap hinge, and the hinges having pivot points that are offset relative to one another, such that the antenna panels can be hinged sequentially one after the other from the stick to a position in which each panel is adjacent a respective base side edge region to provide an extended flat two-dimensional area when deployed.