Abstract: Antenna having a selectively rotatably extendable sensitivity pattern provided by an array of three or more dipole antenna units, each of substantially equal mechanical length and located at the corners of a substantially regular polygon having the same number of sides as the number of units in the array and switching means having connections to each dipole unit to selectively energize at least one of said units and interpose an electrically-lengthening inductive reactance in at least two other units located, with respect to the direction in which the sensitivity is to be extended, behind and on either side of an energized unit to serve as parasitic reflectors extending the lobe of sensitivity of an energized unit in the selected direction.