Embodiments are provided for an agile antenna that beamsteers radio frequency (RF) signals by selectively activating/de-activating tunable elements on radial-waveguides using direct current (DC) switches. The antenna comprises two parallel radial waveguide structures, each comprising a first radial plate, a second radial plate in parallel with the first radial plate, and conductive elements positioned vertically and distributed radially between the two plates. The radial waveguide structure further includes a plurality of quarter RF chokes which are connected to the conductive elements via respective micro-strips and tunable elements. The two parallel radial plates are separated by a height determined according to a desired transmission frequency range for RF signals, a length of the micro-strips, a diameter of the conductive elements, and a clearance space around each one of the conductive elements.