A full-wave solution is presented for the problem of an infinite array of vertical monopoles embedded in a grounded dielectric sheet. Calculated results are compared with experimental data from waveguide simulators for εr= 1 (air) and εr= 2.5 (acrylic) cases. Scan blindness is observed for the dielectric loaded case, and a grating lobe diagram augmented with surface wave circles is used to explain this phenomenon.