Bandgap determination of triangular lattice EBGs in the ground plane

The bandgap of triangular lattice electromagnetic bandgap structure (EBGs) in the ground plane has been determined. It has been observed that the bandgap location is shifted from the case of EBGs in the substrate. The 2-D EBGs in the ground plane has significantly higher value of a / λ g , where a is the lattice constant and λ g is the guided wavelength. Triangular lattice EBGs at Ka band are designed by etching circular cylindrical holes in the ground plane of GaAs substrate and all these EBGs exhibit bandgaps at a higher value of a / λ g ratios (approximately 0.653–0.72, depending on r / a ratio) than conventional EBGs, which are formed by drilling air holes in the substrate. The maximum bandgap is observed for a / λ g equal to 0.653 for r / a = 0.45 .