The present invention relates to an antenna able to cover two opposite angular sectors comprising: first and second excited elements (10,11) each able to radiate a signal beam at a predetermined frequency, at least two reflector elements (20,21,22,23), called first and second reflector elements, able to reflect said beams in opposite directions. According to the invention, said first and second excited elements (10,11) and said at least two reflector elements (20,21,22,23) are aligned, said reflector elements being disposed between said first and second excited elements. At least two reflector elements from among said at least two reflector elements (20,21,22,23) are connected together electrically by a first transmission line (30) of predetermined length so that the reflector elements connected together participate jointly in reflecting the beams in the two opposite directions.