Multiband Electromagnetic Bandgap (EBG) Substrates

Horák, J., Oliva, L., Kovács, P., Raida, Z.

Two ways of implementing multiband EBG structures are discussed. First, attention is turned planar dielectric EBG structures, and the influence of the dielectric lattice constant, elementary Brillouin zone and dielectric permittivity to the EBG properties. More complicated structures formed by several dielectrics are optimized using global optimization techniques in order to maximize the stop-band in the prescribed frequency region. The optimization efficiency is demonstrated on the design of the patch antenna completed by the EBG substrate or superstrate. Second, metallic-dielectric EBG structures without any vertical holes or pins are discussed, and their utilization in the design of single- and multi-band antennas is described.