基于四扇形超材料的电磁吸收特性研究
毕业论文关键词：方向不敏感 宽频带 超材料吸收器 光波段
Properties of electromagnetic absorption of a metamaterial based on a four-fan-ring structure
Abstract :Many metamaterial absorbers can only achieve high absorption ratio to electromagnetic wave at one or several specific frequencies, which extremely affects the flexibility of applications in some areas. While, broadband metamaterial absorbers can keep high rate of absorption, and cover a continuous frequency range, simultaneously. This property attracted much attention. In this paper, I present a new design of direction-insensitive metamaterial absorber, and it exhibits near perfect absorption form the visible to ultraviolet range. Here , we firstly introduce the background and development of the metamaterial along with the absorbers, including the classification, theory, typical designs and current researching situation of the metamaterial. We then introduce the development and main achievements of the broadband metamaterial absorbers. Afterwards, we present the design of this metamaterial absorber based on the four-fan-rings structure. Firstly, the optimized structure of this metamaterial absorber is shown, and the reflection, transmission and absorption of the absorber are calculated through simulation. Simulation shows that the absorber exhibits an absorption of nearly unity at the wavelength of 386.1 nm and a relative absorption bandwidth of 0.548, which refers to the ratio of the full absorption bandwidth over an absorption of 90% to the center wavelength. Besides, two four-fan-rings layers were rotated and two external excitation fields were exchanged during the simulation, in order to prove the direction-insensitive property in this structure. We also analyze the well contributions made by the four-fan-rings dielectric layer with simulation. Finally, we analyze the physical mechanism of the high quality absorption of this absorber by plotting the distribution of the fields inside the structure and considering the properties of materials. This direction-insensitive broadband metamaterial absorber has potential applications in electromagnetic absorption and as the cover material to reduce the optical reflection. It can also be used in ultraviolet protection.
Keywords: direction-insensitive broadband metamaterial absorber
optical regime
目录 1
1绪论 2