共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
3.
为了抑制CDMA800网络下行频段的噪声,利用HFSS和二维电路仿真软件AWR的协同仿真,设计了同轴腔体滤波器,该滤波器利用交叉耦合结构实现了边带外的高抑制性能。所设计滤波器中心频率为875MHz,带宽10MHz;插入损耗〈-0.25dB;回波损耗〉-20dB;带外抑制〉-80dB,满足了设计要求。仿真结果表明:该滤波器结构设计尺寸小、频带宽、带外抑制高、带内插损小等,在通信领域具有良好的应用前景。 相似文献
4.
本文介绍了一种基于缺陷地结构(DGS)的微带岔线型宽带带通滤波器的设计过程。此滤波器以四分之一波长的开路枝节型带通滤波器为原型进行设计和改进,引入了微带岔线和DGS 结构,在增加通带带宽和阻带带宽的同时,使滤波器的带外谐波抑制和带内回波损耗得到了很大的改善。采用HFSS 三维场仿真软件进行S 参数的仿真,从仿真结果可
以看出,所设计的带通滤波器中心频率为11.5GHz,其3dB 相对带宽大于50%,带内插损小于0.3dB。此外,在1-6GHz的第一阻带内,滤波器的带外抑制大于20dB,最大抑制度为52dB;在15-24GHz 的第二阻带内滤波器的带外抑制大于20dB,最大抑制度为46dB。整个滤波器尺寸仅为12mm × 16mm。 相似文献
5.
太赫兹滤波器是太赫兹系统的重要器件,然而它的快速准确设计是难点。基于遗传算法(GA)和有限元法的联合仿真,实现了太赫兹滤波器的快速准确设计。采用HFSS-MATLAB-API脚本库,利用HFSS对于场仿真的精确性,同时在MATLAB中基于遗传算法对结果进一步优化,降低了试探性优化的盲目性。采用该方法设计了210~230 GHz带通滤波器,测试结果表明,带内插损均小于0.6 dB,带外抑制度大于30 dB,验证了该方法的准确性。 相似文献
6.
对滤波器的高精确度理论设计及小误差的工艺实现进行探讨与设计加工。总结了国内外的多种设计经验,讨论了多种类型的滤波器设计方案,选取适当的滤波器结构形式,设计加工了110 GHz的感性窗耦合波导滤波器,其中感性窗耦合结构采用传统机械加工技术实现,与法兰盘结构一并集成。基于高频结构仿真(HFSS)软件进行仿真,结果表明:设计并制作的110 GHz带通滤波器,其中心频率为110 GHz,相对带宽为5%,插入损耗小于1 dB,带内回波损耗大于 20 dB,距中心频率2倍带宽处,带外抑制大于40 dB。 相似文献
7.
8.
9.
该文实现了一个高可靠性、小体积的多路腔体滤波器组,包括四路对一致性要求较高的带通滤波器通道,以及一路由直通线缆和防雷电路板构成的校准通道。通过HFSS进行全腔仿真保证了仿真精度,并在Matlab中编程实现滤波器耦合系数的提取。利用Matlab和HFSS联合仿真的方式缩短了腔体滤波器仿真和调试的时间。设计不规则形状谐振腔,采用多通道滤波器形成整体组件结构的形式实现了系统小型化。通过算法、结构设计、调试技术等共同保证相位一致。利用各种浪涌抑制器件的特点设计三级防雷电路,实现了高可靠性系统保护。 相似文献
10.
为了提高无反射带通滤波器的带宽和衰减,设计一款基于集成无源器件技术的小型化、超宽带、高带外抑制的无反射带通滤波器。该滤波器由无反射低通滤波器、无反射高通滤波器和匹配电路级联而成,无反射低通、高通滤波器级联可实现超宽带,通过在匹配电路的上下频带各引入一个零点的方法,将滤波器的带外抑制峰值提高到了40 dB。通过HFSS软件在硅衬底上对其进行建模仿真,最终实现了所需的无反射带通滤波器。该滤波器的中心频率f_0为2.43 GHz,中心频率处的插入损耗为1.17 dB,BW_(-3dB)≤1.86 GHz,带外抑制≥40 dB,回波损耗在12 dB左右,整体尺寸仅为2.65 mm×1.25 mm。三维电磁场仿真结果表明,该款无反射带通滤波器的相对带宽为76.5%,衰减为40 dB。 相似文献
11.
Thomas M.Trexler 《半导体技术》2004,29(5)
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
12.
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
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.
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
15.
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
16.
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
17.
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
18.
Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it. 相似文献
19.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working. 相似文献
20.
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