Pencil beam patterns obtained by a planar array of parasitic dipoles fed by only one active element

The geometry of a planar array of parasitic dipoles is optimized to modify the pattern of an active dipole above a ground plane, in order to obtain a pencil beam of moderate gain and bandwidth without requiring a complex feeding network. As an example of application, a pencil beam pattern radiated by a planar array of parasitic dipoles fed by only one active dipole at 1.645 GHz is shown.