复合缺陷型电磁帯隙谐振腔

提出了一种复合缺陷型电磁带隙(EBG)谐振腔,通过对该EBG结构的带隙分析,指出该谐振腔可在大尺寸下实现单模工作,提供更大的容差空间,且具有高Q值.数值模拟结果表明,基于复合缺陷EBG结构构成的谐振腔,单模工作条件可以放宽到外圈金属柱直径与周期之比为0.6,内圈金属柱直径与周期比为0.9;而传统中心缺陷型EBG结构的小于0.3.关键词：电磁带隙复合缺陷谐振腔单模

Composite defect electromagnetic band gap cavity

We demonstrate an approach to create a high Q factor two-dimensional (2D) electromagnetic band gap (EBG) structure with composite defects in the center of the structures. By theoretical calculation, we show that a single-mode 2D EBG structure can be created with different ratios of diameter, d, to the lattice period, Λ, in this structure. This structure can achieve high Q factor and single mode operation with large d/Λ of the defect at the first circle around the removed rod in the center. With our structure, the single mode operation can be achieved within d/Λ<0.9 at the defect rods and d/Λ<0.6 at the others. In comparison, the condition of d/Λ<0.3 should be strictly satisfied for the traditional design. These results provide very important guidelines for designing of the 2D EBG structure which can be used in traveling-wave tube device.