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1.
多屏蔽电缆屏蔽衰减的测量方法有两种,吸收钳法和GTEM室法。当屏蔽衰减不大于100dB时,两种测量方法均可采用,而当屏蔽衰减大于100dB时,只能采用GTEM室法。本文将介绍测量屏蔽衰减的基本原理,方法、测量中应注意的问题,并对两种测量方法进行比较。  相似文献   

2.
雷达吸波材料电磁参数的测量方法   总被引:1,自引:0,他引:1  
介绍了驻波法、传输/反射法、开口同轴探头法、自由空间法这四种电磁参数测量方法的基本原理,并比较了各种方法的优缺点。  相似文献   

3.
三维物体表面轮廓测量是获取物体形态特征的一种重要手段,分类讨论了光学三维轮廓测量中所用的技术,介绍了各种技术的基本原理及其特点,重点介绍了以相位测量方法为基础的几种典型光学轮廓测量方法.  相似文献   

4.
基于恒流源的电阻测量   总被引:4,自引:1,他引:3  
详细介绍了两种基于恒流源电路的电阻测量方法(即电压表法和电流表法),分析了电路原理,并给出了实测结果。  相似文献   

5.
双光子吸收截面的测量方法   总被引:3,自引:0,他引:3  
综述了非线性透过率法、Z-扫描技术.双光子诱导荧光法、双光子瞬态吸收光谱法等各种测量双光子吸收截面的方法,分析了各种测量方法的特点。  相似文献   

6.
屏蔽效能的测量方法   总被引:1,自引:0,他引:1  
总结并介绍了几种屏蔽效能的测量方法,包括测量金属板屏蔽效能的小环天线法、测量IC封装屏蔽效能的集成天线法、直接照射法、混响室法和脉冲测量法,并通过对各种方法的比较,说明了各种测量方法的适用范围和优点。  相似文献   

7.
角度测量技术的发展   总被引:11,自引:0,他引:11  
角度测量是向何量计量技术的重要组成部分。本文对近年来常用的几种角度测量方法及其发展进行了介绍,主要介绍了其中最具有发展前途的光学测角技术。对圆光栅测角法、激光干涉测角法和环形激光测角法分别进行了详细的介绍,给出了每种方法的测量原理和应用场合,并指出了各种方法的优缺点。  相似文献   

8.
三维物体表面轮廓测量是获取物体形态特征的一种重要手段,分类讨论了光学三维轮廓测量中所用的技术,介绍了各种技术的基本原理及其特点,重点介绍了以相位测量方法为基础的几种典型光学轮廓测量方法。  相似文献   

9.
从测量原理和实验装置上详细介绍了当前几种测量光纤喇曼增益系数的方法:开关法、脉冲扫描法和单光源测量法,并从泵浦源输出功率、可测喇曼频移、实验装置的复杂性等几个方面分析了几种测量方法的优缺点以及适用的范围,为以后选取恰当的测量方法提供了依据.  相似文献   

10.
接触电阻率测量方法的研究   总被引:2,自引:0,他引:2  
对于金属-半导体欧姆接触,本文介绍了两种接触电阻率的测量方法:两直径法和回归分析法,测量结果较准确.对同一样品,用多种方法测显,比较其结果并对各种测量方法进行了评述.  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

16.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

17.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

18.
The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.  相似文献   

19.
Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.  相似文献   

20.
An insert layer structure organic electroluminescent device(OLED) based on a new luminescent material (Zn(salen)) is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn(salen)/Liq/LiF/A1/CuPc/NPD/Zn(salen)/Liq/LiF/A1. Effective insert electrode layers comprising LiF(1nm)/Al(5 nm) are used as a single semitransparent mirror, and bilayer cathode LiF(1 nm)/A1(100 nm) is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.  相似文献   

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