Antenna unit having a single antenna element and a periodic structure upper plate

摘要

An antenna unit consists of an EBG reflector, a single curl antenna supported at a central portion of the EBG reflector, and a periodic structure upper plate disposed apart from a principal surface of the EBG reflector by a predetermined distance. The EBG reflector includes a substrate having the principal surface and (NxxNy) square patches which are printed on the principle surface of the substrate and which are arranged in a matrix fashion (lattice structure). The periodic structure upper plate consists of a film and (NxxNy) square patch-like conductors printed on the film. The (NxxNy) square patch-like conductors are disposed so as to oppose to the (NxxNy) square patches, respectively.