Transient Fields of a Vertical Dipole Over a Homogeneous Curved Ground

Expressions are derived for the transient fields of a short vertical antenna, situated on a smooth spherical conducting earth, and energized by a current which is discontinuous in time. When the antenna current is a linear function of time, the radiation field on a flat perfectly conducting earth is of step-function form. The departure from the step shape of the field is shown to be due to the finite conductivity and dielectric constant of the ground, the induction and static fields of the antenna, and the curvature of the earth.