基于过孔波导的毫米波近场辐照系统设计与研究
发布时间：2018-08-26 14:28
【摘要】：近年来,随着科学技术的发展,人们对各种毫米波体外辐照装置进行探索和研究并不断改善其结构。本文设计了一种用于细胞辐照实验的60GHz的毫米波体外辐照装置,并且研究了以效率和均匀性为代表的辐照剂量。其中辐照系统构建采用的是过孔波导技术,建模采用的是自适应网格,研究方法采用的是毫米波体外细胞实验数值剂量学方法,论文完成了以下三部分工作:首先设计了一个毫米波辐照系统。这个系统是基于一个介质基片集成的,介质基片是通过印制电路板技术制作。在介质基片的上下表面覆盖一层金属片。在基片中制作两列按照一定距离排列的金属化通孔和耦合阵列。毫米波经过两列耦合孔在介质基片中传输,并通过耦合阵列间隙散射。在耦合阵列上表面加载一个常规培养皿模型。同时用两个对称边界将问题空间优化为原来尺寸的1/4。然后对培养液细胞的比吸收率(SAR)进行仿真。通常辐照系统的网格分辨率在0.125mm左右是可行的。为了提高计算结果的精度,本文采用自适应网格,其中计算空间使用0.1mm的网格分辨率,对不需要结果的周围空间使用0.5mm的网格分辨率。入射波选用频率为60GHz和幅值为1V/m的毫米波。激励源采用离散源,源阻抗为50欧姆。对辐照系统进行仿真,通过观察细胞培养液的SAR分布来分析辐射效率。最后对培养液细胞层的SAR分布进行优化。通过140个周期的仿真我们得到细胞培养液表面SAR分布的相对标准偏差为120%。为了减小SAR分布的相对标准偏差,我们将影响分布的因素进行研究并调整到最优。首先考虑计算周期不足导致SAR结果不正确。增加计算周期,得到最稳定的计算周期为1000个。然后考虑培养皿底座厚度影响SAR分布,在保证SAR均值变化程度不大的条件下,调整培养皿底座厚度来减小SAR分布相对标准偏差,得到最佳培养皿底座厚度为4.5mm。最后,我们考虑到培养皿底座相对介电常数对SAR分布的影响,得到最佳的培养皿底座相对介电常数为2.17。优化得到的培养液细胞层SAR分布的相对标准偏差为75%。
[Abstract]:In recent years, with the development of science and technology, a variety of millimeter-wave irradiation devices in vitro have been explored and studied, and their structures have been continuously improved. In this paper, a millimeter wave in vitro irradiation device of 60GHz for cell irradiation experiment is designed, and the radiation dose represented by efficiency and uniformity is studied. The radiation system is constructed using the perforated waveguide technique, the modeling is adaptive mesh, and the research method is the numerical dosimetry method of millimeter wave cell experiment in vitro. The following three parts are completed: firstly, a millimeter wave irradiation system is designed. The system is based on the integration of a dielectric substrate made by printed circuit board technology. A metal sheet is coated on the upper and lower surfaces of the dielectric substrate. Two columns of metallized through holes and coupled arrays arranged at a certain distance are fabricated in the substrate. The millimeter wave propagates through two rows of coupling holes in the dielectric substrate and scatters through the coupling array gap. A conventional petri dish model was loaded on the surface of the coupled array. At the same time, two symmetric boundaries are used to optimize the problem space to 1 / 4 of the original size. Then the specific absorptivity (SAR) of culture medium cells was simulated. Usually, the grid resolution of irradiated system is about 0.125mm. In order to improve the accuracy of the results, an adaptive mesh is used, in which the grid resolution of 0.1mm is used in the computing space, and the grid resolution of 0.5mm is used in the space around which the result is not required. Millimeter wave with frequency of 60GHz and amplitude of 1V/m is selected for incident wave. The excitation source is discrete source and the source impedance is 50 ohms. The irradiation system was simulated and the radiation efficiency was analyzed by observing the SAR distribution of the cell culture medium. Finally, the distribution of SAR in the cell layer of culture medium was optimized. The relative standard deviation of SAR distribution on the surface of cell culture medium was 120 by 140 cycles simulation. In order to reduce the relative standard deviation of SAR distribution, the factors affecting the distribution are studied and adjusted to the optimum. First of all, consider that insufficient calculation period leads to incorrect SAR results. By increasing the calculation period, the most stable calculation period is 1000. Then considering the influence of the petri dish base thickness on the SAR distribution, the optimum petri dish base thickness is 4.5 mm. by adjusting the petri dish base thickness to reduce the relative standard deviation of the SAR distribution under the condition that the mean value of SAR changes little. Finally, considering the influence of the relative dielectric constant of the petri dish base on the SAR distribution, the optimum relative dielectric constant of the petri dish base is 2.17. The relative standard deviation of SAR distribution in cell layer was 75%.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q2-33;TN015
本文编号：2205157
[Abstract]:In recent years, with the development of science and technology, a variety of millimeter-wave irradiation devices in vitro have been explored and studied, and their structures have been continuously improved. In this paper, a millimeter wave in vitro irradiation device of 60GHz for cell irradiation experiment is designed, and the radiation dose represented by efficiency and uniformity is studied. The radiation system is constructed using the perforated waveguide technique, the modeling is adaptive mesh, and the research method is the numerical dosimetry method of millimeter wave cell experiment in vitro. The following three parts are completed: firstly, a millimeter wave irradiation system is designed. The system is based on the integration of a dielectric substrate made by printed circuit board technology. A metal sheet is coated on the upper and lower surfaces of the dielectric substrate. Two columns of metallized through holes and coupled arrays arranged at a certain distance are fabricated in the substrate. The millimeter wave propagates through two rows of coupling holes in the dielectric substrate and scatters through the coupling array gap. A conventional petri dish model was loaded on the surface of the coupled array. At the same time, two symmetric boundaries are used to optimize the problem space to 1 / 4 of the original size. Then the specific absorptivity (SAR) of culture medium cells was simulated. Usually, the grid resolution of irradiated system is about 0.125mm. In order to improve the accuracy of the results, an adaptive mesh is used, in which the grid resolution of 0.1mm is used in the computing space, and the grid resolution of 0.5mm is used in the space around which the result is not required. Millimeter wave with frequency of 60GHz and amplitude of 1V/m is selected for incident wave. The excitation source is discrete source and the source impedance is 50 ohms. The irradiation system was simulated and the radiation efficiency was analyzed by observing the SAR distribution of the cell culture medium. Finally, the distribution of SAR in the cell layer of culture medium was optimized. The relative standard deviation of SAR distribution on the surface of cell culture medium was 120 by 140 cycles simulation. In order to reduce the relative standard deviation of SAR distribution, the factors affecting the distribution are studied and adjusted to the optimum. First of all, consider that insufficient calculation period leads to incorrect SAR results. By increasing the calculation period, the most stable calculation period is 1000. Then considering the influence of the petri dish base thickness on the SAR distribution, the optimum petri dish base thickness is 4.5 mm. by adjusting the petri dish base thickness to reduce the relative standard deviation of the SAR distribution under the condition that the mean value of SAR changes little. Finally, considering the influence of the relative dielectric constant of the petri dish base on the SAR distribution, the optimum relative dielectric constant of the petri dish base is 2.17. The relative standard deviation of SAR distribution in cell layer was 75%.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q2-33;TN015
【参考文献】
相关期刊论文 前1条
1 牛中奇;侯建强;周永军;王海彬;卢智远;;生物电磁剂量学及人体吸收电磁剂量的数值分析[J];中国生物医学工程学报;2006年05期
，本文编号：2205157
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