Circularly polarised patch antenna with periodic structure

A wideband microstrip patch antenna has been designed that provides circular polarisation with good axial ratio (AR) within a reasonably wide bandwidth. The patch has further been investigated by integrating it with the electromagnetic band gap (EBG) structure, and a significant improvement in several characteristics of the antenna performance has been observed. Antennas and the EBG structure are modelled with the finite-difference time-domain (FDTD) method. Experimental results for the antennas are also presented, and an excellent agreement has been found between the computed and measured results.