Circularly polarized microstrip antenna and radio communication apparatus including the same

摘要

A circularly polarized microstrip antenna includes a dielectric substrate having only an emitting electrode for generating circularly polarized waves on a front surface of the dielectric substrate and a coplanar signal line for feeding the emitting electrode and a ground electrode on a back surface of the dielectric substrate. The ground electrode covers the entire area of the back surface of the dielectric substrate excluding a region in which the signal line is provided. The signal line extends from an edge of the back surface of the dielectric substrate to an intermediate position between the edge of the back surface of the dielectric substrate and a center position O of the emitting electrode on the back surface of the dielectric substrate. Thus, a circularly polarized microstrip antenna whose circular polarization characteristic can be easily improved and whose manufacturing cost and size can be easily reduced is provided.