RESONANT ELEMENT FOR FREQUENCY SELECTIVE PLATE, FREQUENCY SELECTIVE PLATE AND ANTENNA DEVICE

There are provided a plurality of poles (11, 12, 13) whose roots (11a, 12a, 13a) are connected to a central part (10) and whose tips (11b, 12b, 13b) extend in mutually different directions on an identical plane or on an identical curved surface, wherein a pole width at each of the roots (11a, 12a, 13a) is narrower than a pole width between each of the roots (11a, 12a, 13a) and the corresponding one of the tips (11b, 12b, 13b), each pole width being defined by a length of a line segment in a direction perpendicular, on the identical plane or on the identical curved surface, to a line segment connecting each of the roots (11a, 12a, 13a) to a corresponding one of the tips (11b, 12b, 13b) in the respective poles.