Two-dimensional analysis of bandwidth of open hard surface

The field caused by a filament current located on a dielectric slab has been calculated from a full wave solution. The results show that the slab provides that ideally hard boundary condition on the dielectric surface when d=/spl lambda/o/(4/spl radic/(/spl epsi//sub r/-1)), which means that the grounded slab works as an artificial PMC when the E-field is tangential to it. The radiation fields approach the omnidirectional radiation pattern of a PMC when d decreases, i.e. /spl epsi/r increases. The bandwidth of the hard surface is shown to decrease when the length of it increases.