The invention relates to a surface suitable for filtering a plurality of frequency bands, said surface including a set of separate identical basic conductive units (31) that are reproduced in a periodic arrangement on a dielectric substrate (10). The basic unit includes: a tripole consisting of three identical segments (12) that extend radially from a center (14); and two arms (32) that extend symmetrically from an intermediate point of each segment, said intermediate point being located at a common distance (Db) from the center (14) for each of the segments (12). The general directions of both arms form an angle of approximately 120° and define an arrowhead pointed toward the outside, wherein the arms (32) corresponding to two separate segments (12) do not intersect.