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通过分析口径积分、平面波谱理论关于天线近场计算的特点,获得一种混合的天线近场计算方法.结合表面积分技术,提出了口径/谱域积分-表面积分法,用于三维天线-罩系统电性能数值仿真.该方法吸取了口径积分和平面波谱理论的优点,对于天线近场的分析更为精确、实用.以弹载天线罩为仿真实例,结果表明,与口径积分-表面积分法和平面波谱-表面积分法相比,口径/谱域积分-表面积分法的计算结果与实验结果更为吻合,证明了该算法具有更高的精确度. 相似文献
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给出了应用几何绕射理论(GTD)分析计算机载电大尺寸阵列天线方向图的一种方法,比较好地解决了在复杂电磁环境下,大型阵列天线近场受扰分析的问题.该方法将阵列天线的每个阵元看成电偶极子,由于电偶极子尺寸很小,因而可以认为阵列的近场区仍然是单个电偶极子的远场区.根据这样的远场近似,可以利用几何绕射理论用解析方法计算每个电偶极子受到遮挡影响的场分布.通过独立地对阵列天线的每个阵元单独寻迹计算,并且将所有阵元的场进行叠加,就可以得到整个阵列天线受到处于近场的障碍物遮挡影响的场分布.应用此方法计算了一个阵列天线受到近场遮挡之后的方向图,并与应用HFSS仿真软件计算的结果进行了比较.计算结果表明,这一方法可以很好地应用于复杂电磁环境中大型阵列天线的近场受扰问题分析. 相似文献
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在近场测量系统中,天线口径诊断是其中一项重要功能,它能够帮助天线设计师发现相控阵天线设计或者网络配置问题.平面近场中的口径诊断技术已经广泛地应用在雷达天线测试中,在球面近场测量中同样需要这种算法.本文基于球面坐标系下电磁场模式方法,得到球面近场条件下的口径反演算法.在仿真模型中计算得到了被测天线的口径场分布,计算结果与理论模型结果吻合.对X波段阵列天线进行了实际测试,得到了不同配置下的阵列天线口径反演结果,经过数据比对,证明了本文算法的幅度反演精度优于1 dB. 相似文献
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在星载Ku波段谐振式波导缝隙阵列天线设计中,由于结构空间的限制,采用半高非标准波导。考虑到半高波导中更容易产生高次模影响的特点,以及设计成本和效率问题,将基于有限元法的高频电磁仿真软件Ansoft HFSS与Fortran编程相结合应用于该类天线的设计。采用HFSS研究并描述了宽边纵向辐射缝隙和中心倾斜耦合缝隙的特性,结合Elliott提出的经典平面缝隙阵设计理论,用Fortran编程设计了阵元数为80(8×10)的波导缝隙阵列天线实验件,并用HFSS仿真优化了天线阵整体的性能。对实物天线进行了近场测试,结果表明:天线的E面和H面副瓣电平分别是-29dB和-27.5dB,1.3以下驻波带宽为340MHz,与仿真结果基本吻合。良好的测试结果验证了用HFSS获取缝隙特性曲线的正确性及设计方法的有效性,为后期大型阵列设计提供了一种有效的方法。 相似文献
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本文给出了一种Ka 波段对称四波束波导缝隙行波阵列天线的设计方法。该设计对经典行波阵理论进行了改进
和创新,提出将驻波阵的电流幅度分布理论应用于行波阵,推导出多波束波导缝隙的电场分布方程,实现了波导缝
隙阵列天线对称四波束配置,并具备共口径、高增益、低副瓣等优点,满足多普勒测速雷达对天线的要求。HFSS
软件仿真测量结果验证了该设计的正确性。 相似文献
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Meihua Shen Wilfred Pau Nicolas Gani Jianping Wen Shashank Deshmukh Thorsten Lill Jian Zhang Hanming Wu Guqing Xing 《半导体技术》2004,29(8)
This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration. 相似文献
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White organic light-emitting devices based on fac tris(2- phenylpyridine) iridium sensitized 5,6,11,12-tetraphenylnap -hthacene 总被引:1,自引:0,他引:1
We have fabricated the white organic light-emitting devices (WOLEDs) based on 4,4' -bis(2,2 -diphenyl vinyl)-1,1' - biphenyl (DPVBi) and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene (rubrene). The device structure is ITO/2T-NATA (20 nm)/NPBX (20 nm)/CBP: x%Ir(ppy)3:0.5% rubrene (8 nm)/NPBX (5 nm)/DPVBi (30 nm)/Alq(30 nm)/LiF(0.5 nm)/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris (2-phenylpyridine) iridium [Ir(ppy)3], acts as a yellow light-emitting layer, and N,N' -bis- (1-naphthyl)- N,N' -diphenyl -1, 1' -biphenyl-4,4' -diamine (NPBX) acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir (PPY)3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V. 相似文献
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Complete approach to automatic identification and subpixel center location for ellipse feature 总被引:1,自引:0,他引:1
XUE Ting WU Bin SUN Mei YE Sheng-hua 《光电子快报》2008,4(1):51-54
To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction. 相似文献
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In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy. 相似文献
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High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center. 相似文献
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Credence Systems Corporation 《半导体技术》2004,29(9)
Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V. 相似文献
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This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors. 相似文献
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YUXiao-hua XIANGYu-qun 《半导体技术》2005,30(2):30-32,37
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB. 相似文献
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It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer (LDV). 相似文献