A circularly polarized microstrip antenna with a photonic bandgap ground plane

The characteristics of a corner-truncated square microstrip antenna with a photonic bandgap (PBG) ground plane have been experimentally studied. Results indicate that, when the PBG structure in the ground plane has a stopband for EM wave propagation covering the operating frequencies of the circularly polarized microstrip antenna studied, enhanced antenna performances can be obtained even for the case where a thin dielectric substrate is used. Details of the PBG structure studied and the obtained experimental results are presented.