Abstract: Disclosed is a loop type antenna, fed by a coaxial line, comprising:a symmetrical, plane, loop-shaped radiating element enclosed on itself, connected to the core of the coaxial feed line at one point of the loop;a reflector plane extending in parallel to the plane of the loop and at a distance from it; and,a symmetrizer element in the shape of a metallic plate, placed between the loop and the reflector and extending in parallel to the plane of the loop and to that of the reflector plane, with a general shape substantially corresponding to the shape of that portion of the loop which is connected to the core of the coaxial line, this plate being connected to the ground of the coaxial feed line. The disclosure also concerns an array antenna comprising an ordered grouping of several antennas, excited simultaneously, said loop and said plate of each antenna extending over a common reflector plane.