Circularly polarized omnidirectional antenna, array antenna and polarization diversity communication system using the same

摘要

The present invention provides a low profile circularly polarized antenna which can be easily colinear arrayed. An antenna (1) is arranged such that dipole antennas whose phases are inverted with each other are offset with respect to a horizontal plane to be point symmetric with respect to a feeding point at a predetermined distance apart by at least one pair. The dipole antenna has a shape having current components in the vertical and horizontal directions when viewed from two orthogonal directions in the horizontal plane, and is fed by the feeding part from the central feeding point. [Effect] It becomes circular non-directional in circular polarization horizontal plane with low profile. Also, by forming the antennas in a co-linear array, a polarization diversity system can be easily configured. [Selected figure] Figure 1A