Analysis of the Effect of Finite Circular Ground Plane on the Wire Monopole Antennas

In this paper, the effect of the finite ground plane on the antenna radiation pattern is analyzed and presented. The radiation pattern of simple wire monopoles and a blade-shaped meanderline monopole - that loaded with lumped elements and covers the 30-500MHz bandwidth - is calculated using the Geometrical Theory of Diffraction (GTD) and the Equivalent Edge Current (EEC) analytical methods. Results show that the GTD method loses its efficiency when the ground plane is small and the EEC Method results a more accurate far field pattern in this case.