A microstrip patch antenna with metamaterial and EBG structures

We numerically investigate the performance of rectangular patch antenna combined with fishnet metamaterial as superstrate for enhanced directionality. The gain of the antenna is improved further by suppressing surface wave in the substrate by using two different methods (1) partial removal of substrate around the patch and (2) mushroom type electromagnetic (EBG) structure. In either case overall gain and directionality of the antenna are greatly improved, however in case of latter the beamwidth of emission is slightly larger and side lobes are smaller as compared to former. To best of our knowledge this is the first design of patch antenna employing both EBG and novel fishnet metamaterial for enhanced performance.