基于過孔波導(dǎo)的毫米波近場輻照系統(tǒng)設(shè)計(jì)與研究
發(fā)布時(shí)間：2018-08-26 14:28
【摘要】：近年來,隨著科學(xué)技術(shù)的發(fā)展,人們對各種毫米波體外輻照裝置進(jìn)行探索和研究并不斷改善其結(jié)構(gòu)。本文設(shè)計(jì)了一種用于細(xì)胞輻照實(shí)驗(yàn)的60GHz的毫米波體外輻照裝置,并且研究了以效率和均勻性為代表的輻照劑量。其中輻照系統(tǒng)構(gòu)建采用的是過孔波導(dǎo)技術(shù),建模采用的是自適應(yīng)網(wǎng)格,研究方法采用的是毫米波體外細(xì)胞實(shí)驗(yàn)數(shù)值劑量學(xué)方法,論文完成了以下三部分工作:首先設(shè)計(jì)了一個(gè)毫米波輻照系統(tǒng)。這個(gè)系統(tǒng)是基于一個(gè)介質(zhì)基片集成的,介質(zhì)基片是通過印制電路板技術(shù)制作。在介質(zhì)基片的上下表面覆蓋一層金屬片。在基片中制作兩列按照一定距離排列的金屬化通孔和耦合陣列。毫米波經(jīng)過兩列耦合孔在介質(zhì)基片中傳輸,并通過耦合陣列間隙散射。在耦合陣列上表面加載一個(gè)常規(guī)培養(yǎng)皿模型。同時(shí)用兩個(gè)對稱邊界將問題空間優(yōu)化為原來尺寸的1/4。然后對培養(yǎng)液細(xì)胞的比吸收率(SAR)進(jìn)行仿真。通常輻照系統(tǒng)的網(wǎng)格分辨率在0.125mm左右是可行的。為了提高計(jì)算結(jié)果的精度,本文采用自適應(yīng)網(wǎng)格,其中計(jì)算空間使用0.1mm的網(wǎng)格分辨率,對不需要結(jié)果的周圍空間使用0.5mm的網(wǎng)格分辨率。入射波選用頻率為60GHz和幅值為1V/m的毫米波。激勵(lì)源采用離散源,源阻抗為50歐姆。對輻照系統(tǒng)進(jìn)行仿真,通過觀察細(xì)胞培養(yǎng)液的SAR分布來分析輻射效率。最后對培養(yǎng)液細(xì)胞層的SAR分布進(jìn)行優(yōu)化。通過140個(gè)周期的仿真我們得到細(xì)胞培養(yǎng)液表面SAR分布的相對標(biāo)準(zhǔn)偏差為120%。為了減小SAR分布的相對標(biāo)準(zhǔn)偏差,我們將影響分布的因素進(jìn)行研究并調(diào)整到最優(yōu)。首先考慮計(jì)算周期不足導(dǎo)致SAR結(jié)果不正確。增加計(jì)算周期,得到最穩(wěn)定的計(jì)算周期為1000個(gè)。然后考慮培養(yǎng)皿底座厚度影響SAR分布,在保證SAR均值變化程度不大的條件下,調(diào)整培養(yǎng)皿底座厚度來減小SAR分布相對標(biāo)準(zhǔn)偏差,得到最佳培養(yǎng)皿底座厚度為4.5mm。最后,我們考慮到培養(yǎng)皿底座相對介電常數(shù)對SAR分布的影響,得到最佳的培養(yǎng)皿底座相對介電常數(shù)為2.17。優(yōu)化得到的培養(yǎng)液細(xì)胞層SAR分布的相對標(biāo)準(zhǔn)偏差為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%.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：Q2-33;TN015
本文編號：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%.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：Q2-33;TN015
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 牛中奇;侯建強(qiáng);周永軍;王海彬;盧智遠(yuǎn);;生物電磁劑量學(xué)及人體吸收電磁劑量的數(shù)值分析[J];中國生物醫(yī)學(xué)工程學(xué)報(bào);2006年05期
，本文編號：2205157
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