A magnetic dipole antenna in the shape of a half ellipse at 5.8GHz has been proposed here for the first time. The drawback of elliptical micro-strip patch antenna as a linearly polarized antenna is poor polarization purity. Narrow half power beam-width(HPBW) is a traditional shortcoming of micro-strip patch antenna. The proposed antenna has wide half power beam-width and a low cross-polarization characteristic. By parameter study with various sizes of half ellipse magnetic dipole antennas, fractional bandwidth also has been improved.