The Influence of Cavity‐defect Shapes on Resonant Peak of Three‐dimensional Electromagnetic Band Gap Structure

Localized mode is an important property of defect electromagnetic band gap ( EBG ) structure, which plays a key role in the application of EBG structure. The purpose of this article was to study the impact on localized properties by introducing cavities of different shapes into diamond EBG structure. Alumina‐based ceramic diamond EBG structures were fabricated using stereolithography ( SL ), gel‐casting and vacuum freeze‐drying. When the microwave transmission properties of samples with cavities of different shapes were tested, the resonant peaks appeared within the band gap. By varying the cavity shape, the quality of the localized mode could be adjusted. The results have shown that localized mode with a high quality factor ( Q factor) corresponded to the optimal cavity shape in EBG structure. The experimental results agreed well with simulation results. These excellent microwave properties of 3D EBG structure could be directly applied in microwave devices, such as microwave antenna and filter devices.