基于时间反演电磁理论的赋形电磁场产生研究

发布时间：2018-06-11 21:00

本文选题：电磁波控制 + 时间反演　；参考：《电子科技大学》2015年硕士论文

【摘要】：电磁波的传播与控制一直都是电磁学领域中备受关注的基础性研究课题。随着电磁波的应用范围不断扩大,特别是近年来在医疗、工业、农业、化学等领域中的推广应用,使得电磁波的传播及其空间场的控制研究面临着全新的技术挑战。结合亚波长和超材料进行空间电磁场的传播与控制是一种有效的方法,但其存在一定的局限性:一是目前只能实现单频点或窄带“空间场”的控制,二是特定的场需要特定的结构,结构一旦设计好,就不能改变,不具备普适性。理论上,利用格林函数也可以实现任意场的产生与控制,但是却需要大量的计算和优化。如何突破这些限制,是一个巨大挑战性课题。针对上述技术难题,本论文基于时间反演(Time Reversal,TR)空时聚焦传输原理,提出了一种宽频带电磁波空间场赋形设计方法,并在有限的空间范围内成功的实现了多种特定形状的宽频带电磁波空间场赋形。本文所提方法突破了现有电磁场控制方法的窄频带限制,而且无需改变系统结构,就可以构建出多种几何形状的赋形场,具有高度的灵活性和普适性。本论文工作内容如下:首先,基于唯一性定理,理论分析了TR传输的电磁场空时聚焦原理,并基于这一聚焦原理,提出了一种宽频带空间场赋形实现方法。其次,采用所提赋形场实现方法,研究了在自由空间中实现L形的空间场赋形,并对影响赋形场效果的主要参数进行了分析。然后,基于同样的赋形场实现方法,研究了在含有复杂散射体环境下,实现特定几何形状的空间场赋形,并提出一种能有效改进赋形场外形轮廓的赋形场源构造方法。最后,建立了基于TR技术的L形电磁场赋形的实验系统。通过仿真和实验的对比,验证本文所提赋形场实现方法的有效性。
[Abstract]:The propagation and control of electromagnetic wave has always been a basic research topic in the field of electromagnetism. With the continuous expansion of electromagnetic wave applications, especially in recent years in the medical, industrial, agricultural, chemical and other fields, the electromagnetic wave propagation and space field control research is facing a new technical challenge. It is an effective method to control the propagation and control of space electromagnetic field by combining subwavelength and metamaterials, but it has some limitations: first, it can only realize the control of "space field" at single frequency point or narrow band at present. Second, a specific field needs a specific structure, once the structure is well designed, it can not be changed and has no universality. In theory, any field can be generated and controlled by Green's function, but it needs a lot of calculation and optimization. How to break through these restrictions, is a huge challenge. In this paper, based on the space-time focusing transmission principle of time inversion time Reversaler (TRT), a design method of spatial configuration of wide-band electromagnetic waves is proposed. And in the limited space range, we successfully realize a variety of special shapes of broadband electromagnetic wave spatial field shape. The method proposed in this paper breaks through the narrow band limit of the existing electromagnetic field control methods and can construct a variety of geometric shape forming fields without changing the structure of the system. It has high flexibility and universality. The work of this paper is as follows: firstly, based on the uniqueness theorem, the space-time focusing principle of tr transmission is analyzed theoretically, and based on this principle, a wide-band spatial field shaping method is proposed. Secondly, the realization of L-shape in free space is studied by using the proposed method of shape field realization, and the main parameters that affect the effect of shape field are analyzed. Then, based on the same shape field realization method, the spatial field shape with complex scattering object is studied, and a method to construct shape field source is proposed, which can effectively improve the shape profile of shape field. Finally, an experimental system of L shape electromagnetic field shaping based on tr technology is established. Through the comparison of simulation and experiment, the validity of the method proposed in this paper is verified.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O441.4

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