The checkerboard surface, combining two different designs of EBG structures (EBG1 and EBG2), were designed and simulated with Ansys HFSS. The simulations and measurements are in excellent agreement both in terms of RCS reduction bandwidth and monostatic RCS scattering patterns.
It is verified that a wider 10-dB RCS reduction bandwidth of over 60% is obtained by combining two different types of EBG structures for the square and hexagonal checkerboard surfaces. Because the scattered fields are redirected toward four and six directions for the square and hexagon, respectively, the maxima of the bistatic RCS for the checkerboard surfaces are −8.1 and −8.9 dB than those of the PEC ground planes.
For the hexagonal checkerboard surface, the maxima of the RCS scattering patterns are reduced more than those of the square checkerboard surface because the bistatic main lobes are redirected toward six directions, instead of four for the square surface.