Radiation pattern and field intensity of antenna on the ogival ground plane was calculated. The problem which causes the difficulties in calculating radiated field by antenna on the finite ground plane is diffracted field by discontinuities of ground plane. In cases of large ground size in comparison with wavelength, diffracted field can be calculated by GTD(Geometrical Theory of Diffraction). In this thesis, considering large ground plane, diffracted field by antenna on the ogival ground plane was calculated by GTD. Total field was presented as a summation of GO(Geometrical Optic) field and diffracted field. Diffracted field calculated by GTD was compared with that by Michaeli's equivalent current method and proved to be exact considerably and efficient in computing time.
