权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Control of electromagnetic waves by using fractal structures

利用分形结构控制电磁波

基本信息

批准号：
16204020
负责人：
TAKEDA Mitsuo
金额：
$ 32.12万
依托单位：
SHINSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

项目摘要

(1) "Right Angle Scattering Spectra of 3D Fractal Menger Sponge by Using Terahertz. Time-Domain Spectroscopy"We fabricated Menger sponges made of brass and measured transmission and right angle scattering spectra. In stage 2, clear minima are seen at around 2.0 cm^<-1> and 5.0 cm^<-1> in the transmission spectra. Corresponding to the minimum, a sharp peak is seen at in the right scattering These wavelengths correspond to the cut-off modes of the square rods of the Menger sponge.(2) "Using 1D Fractal Cantor-bar Microstrip Lines to Control Microwaves"We fabricated Cantor-bar microstrip lines, and measured and simulated their transmission and reflection spectra. In the stage 3 Cantor-bar, the transmission spectra showed gaps and localized modes appeared in the gap regions. Q factor of the intermediate structure revealed the largest value.(3) "Theoretical analysis of localized electromagnetic eigenmodes in the Menger sponge fractal"The eigenfrequency, field distribution, and quality factor of the localized electromagnetic eigenmodes in the metallic and dielectric Menger sponge were analyzed accurately by the method of dipole radiation with the symmetry-adapted boundary conditions based on the FDTD finite-difference time-domain calculation. The spectra of the eigenfrequency agree quite well with the peaks in the 90-degree light scattering spectra. It is shown that the LCAO approximation gives a good guiding principle for the analysis of scaling (self-similar) properties of the localized modes.(4) "Rigorous solution for electromagnetic waves propagating through pre-Cantor sets"We study one-dimensional systems constructed from a segment by employing the Cantor-set rule up to an arbitrary stage of self-similar patterns. The transmission spectra change drastically with the increase of the stage. At rather high stage the periodicity hidden in the self-similarity comes out.

(1)“基于太赫兹的三维分形门格尔海绵直角散射光谱”。“我们制作了由黄铜制成的门格尔海绵，并测量了透射光谱和直角散射光谱。在阶段2，在透射光谱中可以看到明显的最小值在2.0 cm^<-1>和5.0 cm^<-1>左右。与最小值相对应的是，在右边的散射中可以看到一个尖锐的峰值，这些波长对应于门格尔海绵的方形棒的截止模式。(2)“利用一维分形康托棒微带线控制微波”制备了康托棒微带线，并对其透射和反射光谱进行了测量和模拟。在第3阶段康托棒中，透射光谱出现间隙，并且在间隙区出现局域模式。中间结构的Q因子值最大。(3)《门格尔海绵分形中局域化电磁本征模的理论分析》采用基于时域有限差分法计算对称性适应边界条件的偶极子辐射方法，对金属和介质门格尔海绵中局域化电磁本征模的本征频率、场分布和品质因子进行了精确分析。本征频率的谱与90度光散射谱的峰吻合得很好。结果表明，LCAO近似为分析局域模的标度（自相似）性质提供了良好的指导原则。(4)“电磁波通过前康托集传播的严格解”我们研究了由一段构成的一维系统，采用康托集规则直到自相似模式的任意阶段。透射光谱随级的增加而急剧变化。在较高的阶段，隐藏在自相似中的周期性显现出来。