Microstrip patch antenna with annular ring PBG

In this paper, an improved PBG lattice deviating from square lattice on a microstrip patch antenna is proposed. Both circular and annular ring slots are investigated on the ground plane of patch antenna. The effectiveness of each of the cases is discussed for the suppression of the higher harmonics and surface waves. Antenna performance at resonant frequency of annular ring PBG is compared with circular slotted PBG and conventional patch antenna. Experimental results are also reported to validate the simulated performance.