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91.
用殷钢波导控制相控阵天线的监测精度 总被引:1,自引:1,他引:0
有效地控制某系统相控阵天线的指向精度,是保证整个系统精确定位的关键问题。这里介绍了如何利用殷钢材料的温度特性以及选用殷钢材料的波导来做监测歧管,保证监测精度的设计依据。 相似文献
92.
To get the scattering loss of the trapezoidal core waveguide, a new analysis model is presented based on the perturbation
equivalent method and modified effective-index method. Firstly, the trapezoidal core waveguide is successfully equivalent
to the rectangular one with both restricting the same optical field energy by adopting the perturbation method. Then, the
equivalent rectangular core waveguide is decomposed into two slab waveguides by employing the modified effective-index method.
The trapezoidal core waveguide scattering theory model is established based on the slab waveguide scattering theory. With
the sidewalls surface roughness in the range from 0 to 100 nm in the single model trapezodial core waveguide, optical simulation
shows excellent agreement with the results from the scattering loss model presented. The relationship between the dimension
and side-wall roughness with the scattering loss can be determined in the trapezoidal core waveguide by the scattering loss
model. 相似文献
93.
提出了一种新的计算基片集成波导等效宽度的方法,与已有的计算方法相比,该方法计算准确,实现简单,提取参数少。文章最后通过对比基片集成波导以及与其等效的矩形波导的截止频率,验证了该方法的正确性。 相似文献
94.
Sang-Hoon Shin Sung-Dae Kim Jong-Ha Moon Jin-Hyeok Kim 《Journal of Electroceramics》2006,17(2-4):1097-1101
Er3+/Pr3+ co-doped soda-lime glass thin films have been fabricated using RF magnetron sputtering method and their structural and optical
properties have been studied. Deposition rate, crystallinity, and composition of glass thin films were investigated by scanning
electron microscopy, transmission electron microscopy, and electron probe micro area analysis. Refractive index, birefringence
and binding characteristics have been investigated using a prism coupler and X-ray photoelectron spectroscopy. Er3+/Pr3+ co-doped soda lime glass thin films were prepared by changing substrate temperature (room temp. ∼550∘C), RF power (90 W–130 W), and Ar/O2 gas flow ratio at processing pressure of 4 mTorr. Glass thin films could be obtained at the optimized processing condition
at 350∘C, RF power of 130 W, and gas flow of Ar:O2 = 40:0 with maximum deposition rate of 1.6 μm/h. Refractive index and birefringence increased from 1.5614 to 1.5838 and from
0.000154 to 0.000552, respectively, as the content of Pr3+ increased. Binding energy of Pr3d also increased as the content of Pr3+ increased. 相似文献
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98.
A numerical scheme based on the method of fundamental solutions is proposed for the solution of two-dimensional boundary inverse
Stokes problems, which involve over-specified or under-specified boundary conditions. The coefficients of the fundamental
solutions for the inverse problems are determined by properly selecting the number of collocation points using all the known
boundary values of the field variables. The boundary points of the inverse problems are collocated using the Stokeslet as
the source points. Validation results obtained for two test cases of inverse Stokes flow in a circular cavity, without involving
any iterative procedure, indicate the proposed method is able to predict results close to the analytical solutions. The effects
of the number and the radius of the source points on the accuracy of numerical predictions have also been investigated. The
capability of the method is demonstrated by solving different types of inverse problems obtained by assuming mixed combinations
of field variables on varying number of under- and over-specified boundary segments. 相似文献
99.
针对电介质介电常数的传统测量方法对试样形状要求严格和对有生命物质不易实现等方面的弊端 ,本文研究了终端开口波导法确定电介质相对介电常数εr 的测量原理和方法 ,给出了计算εr 的拟合解 ,并在自行设计的微波CAT (ComputerAidedTest)系统上实现了自动测量 .实验结果表明 ,该方法原理清晰、测试简捷、精度较高 ,尤其适合对有生命物质相对介电常数的测量 相似文献
100.
通过理论和实验两方面,对A.J.Fresnel和J.Fraunhofer圆孔衍射中心图案进行分析和讨论之后,得出圆孔衍射图样中央光斑不一定总是亮斑的结论。 相似文献