Collapsible feed structures to further improve the ability of a reflector antenna (e.g., a spherical balloon reflector antenna) to collapse are disclosed. In a first embodiment, feed systems that include a metallic layer deposited on a dielectric support curtain (e.g., the dielectric support curtain of a spherical balloon antenna), one or more Vee antenna structures, patterned on the metallic layer, that receive a signal reflected off a reflective surface and/or emit a signal that is reflected off a reflective surface, and one or more slot line transmission lines, patterned on the metallic layer, that transmit a signal to and/or from one of the Vee antenna structures. In a second embodiment, a collapsible line feed that includes a plurality of metallic disks and a flexible monopole passing through the plurality of metallic disks.