LAUSR

The transmission properties of a three-dimensional electromagnetic bandgap (EBG) with a diamond structure made of titanium dioxide ceramic using three-dimensional (3-D) printing was studied. The experimental results show that EBG structures can form a wider bandgap with high-K materials for the standard <100> direction, the standard <110> direction, and the standard <111> direction. This agrees well with the simulation using the plane-wave expansion method. However, the bandgap changes gradually when the EBG structure is rotated from one crystal orientation to another. It is also found that the position and the bandwidth associated with the bandgap differ for different angles of incidence, reaching the maximum bandwidth at 22.5°. The results of this study can help facilitate many applications with omnidirectional transmission properties of three-dimensional EBGs.