Abstract: The antenna is provided with: a conductor; an EBG structure that is disposed above the conductor and that contains plural square elements arranged in a matrix; and a radiation element disposed above the EBG structure. A distance L1 between the conductor and the EBG structure satisfies 0.01?0?L1?0.15?0, preferably satisfies 0.025?0?L1?0.085?0, and more preferably satisfies 0.035?0?L1?0.07?0, where an wavelength of a design center frequency of the radiation element is denoted by ?0.

Abstract: An omnidirectional vertical polarization antenna is configured of monopole antennas, the number of which is k (k?3), disposed on a circumference of a circle at equal spaces. An omnidirectional horizontal polarization antenna is configured of first to m-th omnidirectional antennas stacked in m (m?2) layers in a first direction perpendicular to a reflector, and each of the first to m-th omnidirectional antennas is configured of half-wave dipole antennas, the number of which is n. The half-wave dipole antennas, the number of which is n (n?3), configuring each of the first to m-th omnidirectional antennas are respectively configured of arc-shaped conductive bodies, and disposed, at equal spaces, on each of circumferences of circles, the number of which is m, having different diameters, when viewed from a direction opposite to the first direction. The first to m-th omnidirectional antennas are stacked from the reflector in the first direction.