基于微带谐振器的微波微等离子体线性阵列的特性研究

发布时间：2018-03-06 09:09

本文选题：微波微等离子体线性阵列　切入点：微带谐振器　出处：《华东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：微等离子体是指体积被限制在一个有限空间内,气体放电尺寸一般在毫米或微米级别的等离子体。由于微等离子体放电尺寸缩小,使得其具有不同于普通等离子体的特性。首先,微等离子体能够稳定的存在于大气压下,具有较高的等离子体密度和较好的稳定性;其次,微等离子体对气体和能量的消耗较低,可降低其使用成本;此外,小尺寸使得微等离子体设备轻巧、便携、易于集成。因此微等离子体在纳米材料合成、微机械系统、微化学分析、光子器件及生物材料加工等领域具有广泛的应用前景。本文基于微带谐振器阵列,在空气中,对微带谐振器激发的微波微等离子体线性阵列的特性进行多维度的深入探究分析。首先,文章简要介绍了微等离子体基本理论、微带谐振器工作原理和耦合模理论等。其次,在0～20GHz频率范围内对微带谐振器阵列进行数值仿真,并研究阵列放电缝隙上方覆盖聚四氟乙烯材料对缝隙处电场强度的影响。最后,通过实验,研究真空度、微波频率和输入功率对微带谐振器阵列的S参数、谐振频率及微波微等离子体线性阵列的激励特性、放电强度、放电区域和发射光谱等的影响,并估算出实验中微波微等离子体线性阵列的电子温度及电子密度。仿真研究表明,在0～20GHz频率范围内,微带谐振器阵列具有多谐性,除主模 2.45GHz 外,还有 7.3GHz、8.21GHz、10.35GHz、13.94GHz、15.74GHz 和17.95GHz等6个谐振频率;当在放电缝隙上方覆盖聚四氟乙烯材料时,阵列各单元缝隙处的场强均匀性明显改善。实验研究表明,减小真空度,放电区域减小,微波微等离子体线性阵列出现断裂,亮度减弱,微波微等离子体线性阵列的电子温度和电子密度减小。保持输入功率不变,在(6.2～45)Torr范围内,真空度为17.9Torr时,|S11|有最小值0.274;当真空度为6.2Torr时,线性阵列有8个单元成功激励,且放电区域及亮度最大,此时电子温度约为0.61eV(7078K),电子密度为7.97*1017cm-3;当真空度约为45Torr时,微波微等离子体线性阵列熄灭。保持真空度3.3Torr不变,当输入功率为21.73W时,微波微等离子体线性阵列激励起8个单元;当输入功率为20.4W时,微波微等离子体线性阵列出现断裂;当输入功率低于18.6W时,微波微等离子体线性阵列全部熄灭。微波微等离子体线性阵列激励后,微波微等离子体线性阵列源的谐振频率由2472MHz分别增大至2487MHz和2495MHz,微波微等离子体线性阵列激励的带宽约为125MHz。
[Abstract]:A microplasma is a plasma whose volume is confined to a finite space and the discharge size of a gas is generally in millimeter or micron. It has different characteristics from ordinary plasma. Firstly, microplasma can exist stably at atmospheric pressure, with higher plasma density and better stability. Microplasmas consume less gas and energy, reducing their cost of use; in addition, small sizes make microplasma devices lightweight, portable and easy to integrate. Therefore, microplasmas are synthesized in nanomaterials, micromachined systems, Microchemical analysis, photonic devices and biomaterial processing have a wide range of applications. In this paper, based on microstrip resonator array, in the air, The characteristics of microwave microplasma linear array excited by microstrip resonator are analyzed in detail. Firstly, the basic theory of microplasma, the working principle of microstrip resonator and coupled mode theory are briefly introduced. The microstrip resonator array is numerically simulated in the frequency range of 0 ~ 20GHz, and the influence of PTFE material on the electric field intensity of the gap is studied. Finally, the vacuum degree is studied by experiments. The effects of microwave frequency and input power on the S parameters, resonant frequency and excitation characteristics, discharge intensity, discharge region and emission spectrum of the microstrip resonator array. The electron temperature and electron density of the microwave microplasma linear array are estimated. The simulation results show that the microstrip resonator array has multi-harmonics in the frequency range of 0 ~ 20 GHz, except for the main mode 2.45 GHz. There are also 6 resonance frequencies of 7.3GHz / 8.21GHz / 10.35GHz / 10.35GHz / 13.94GHz / 15.74GHz and 17.95GHz respectively, and the uniformity of the field strength at the gap of the array is obviously improved when the discharge gap is covered over the gap. The experimental results show that the discharge region decreases when the vacuum degree decreases, and the discharge region decreases when the discharge gap is covered with polytetrafluoroethylene. The microwave microplasma linear array is broken, the brightness is weakened, and the electron temperature and electron density of the microwave microplasma linear array are decreased. When the vacuum degree is 17.9 Torr, S11 has a minimum value of 0.274.When the vacuum degree is 6.2 Torr, the linear array has 8 units excited successfully, and the discharge region and brightness are the highest. The electron temperature is about 0.61eV ~ (1) 7078KN, the electron density is 7.971017cm-3, and the vacuum is about 45Torr. The microwave microplasma linear array is extinguished. The vacuum degree of 3.3Torr is kept unchanged. When the input power is 21.73W, the microwave microplasma linear array is excited by 8 units, and the microwave microplasma linear array breaks when the input power is 20.4 W. When the input power is less than 18.6 W, the microwave microplasma linear array is extinguished. The resonant frequency of microwave microplasma linear array source increases from 2472 MHz to 2487 MHz and 2495 MHz, respectively. The bandwidth of microwave microplasma linear array excitation is about 125 MHz.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN629.1;O53

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