Effects of photonic band gap substrates on microstrip antenna performance

Patch antennas have some limitations such as restricted bandwidth of operation, low gain and a potential decrease in radiation efficiency due to surface wave losses. In this paper, the ability of a photonic band gap (PBG) substrate to minimize the surface wave effects is analyzed for a thick and high ϵr substrate. In this work, the substrate of a microstrip antenna is loaded with a 2D triangular lattice of circular holes to give the PBG structure. The PBG patch antenna showed significantly reduced levels of surface modes compared to a conventional patch antenna, thus improving the gain and far-field radiation pattern. An effort is also made to study the effect on the antenna pattern of the dielectric contrast between the host material and atoms in the PBG structur