两通道完全重构滤波器组的设计方法:因式分解法

本文首先研究了两通道滤波器组设计的完全重构的条件以及Euclidean多项式的性质,提出了基于因式分解的两通道完全重构滤波器组的设计方法.该方法不需要进行强的非线性优化计算而可以实现真正的结构化的完全重构滤波器组.文中描述了这种方法的推导过程,给出了设计步骤,最后通过给出的设计例子,说明该方法是有效的.     

无约束法设计完全重构M带滤波器组

本文提出了一种新的正交和双正交完全重构M带滤波器组的设计方法.这种方法是建立在多项式分解基础之上,可在无约束条件下设计,所设计的滤波器组具有结构化完全重构特点,对于双正交滤波器组还可以方便设计系统时延.和已有的方法相比,新方法具有低设计复杂度特点.文中还描述了设计过程,最后给出了设计例子和结果.     

两通道完全重构滤波器组的设计方法:因式分解法

本文首先研究了两通道滤波器组设计的完全重构的条件以及Euclidean多项式的性质 ,提出了基于因式分解的两通道完全重构滤波器组的设计方法 .该方法不需要进行强的非线性优化计算而可以实现真正的结构化的完全重构滤波器组 .文中描述了这种方法的推导过程 ,给出了设计步骤 ,最后通过给出的设计例子 ,说明该方法是有效的     

FIR完全重建滤波器组构造双正交小波基

本文论述了由双正交完全重建滤波器组构造高度正则的双正交小波基的充分条件和构造方法，系统地研究了双正交线性相位ＦＩＲ完全重建滤波器组的解的结构和已知Ｈ０（ｚ）构造完全重建滤波器组的方法，并且实现了用单一的传递函数Ａ（ｚ）构造线性相位ＦＩＲ双正交完全重建滤波器组的设计方法。这种方法的突出优点是滤波器组分析、合成部分中的滤波器可以用数值优化的方法使两者同时逼近理想低通滤波器和理想高通滤波器，即具有良好的频率选择性，并且所有滤波器都具有线性相位的特点。该滤波器组具有良好的梯形实现结构。在具体的滤波器设计中提出了基于均方误差最小准则的特征滤波器的设计方法和基于误差最大值最小准则的Ｒｅｍｅｚ交换法。而且上述方法设计的滤波器组可以构造出具有高度正则性的光滑的双正交小波基。     

利用频率掩蔽法设计均匀和非均匀余弦调制滤波器组

给出了一种均匀非均匀余弦调制滤波器组的设计方法。采用了频率掩蔽法设计原型滤波器,利用迭代算法优化原型滤波器的脉冲响应系数,目标函数表示为脉冲响应系数的四次方,非均匀余弦调制滤波器组通过合并均匀余弦调制滤波器组的相邻的滤波器得到,这种方法简单有效。最后的Matlab实例仿真验证了此算法的有效性。     

基于多项式分解理论的低时延完全重构两通道滤波器组的设计

Euclid多项式分解算法可以用于滤波器组的设计,该文首先讨论了Euclid分解算法与低时延两通道完全重构的滤波器组设计理论,推导出可实现分解的条件,并从理论上加以证明,由于Euclid分解算法具有非唯一性,该文提出了一种新的算法以确定唯一的分解,并将这种算法用于具有低时延特性的两通道全重构滤波器组的设计,最后,通过给出的基于分解方法的设计例子,说明该方法是有效的。     

基于OPG理论的自适应滤波器设计及其在图像处理中的应用

本文基于单参数变换群理论提出了一种新的自适应滤波器的设计方法,并且给出了滤波器与图象卷积的算法.参数变化后的滤波器的可以表示为事先给定的一组基本滤波器的线性组合.这种滤波器在不同方向、尺度和位置上和图像进行卷积时,可以显著提高运算效率.最后给出了一个图像边缘提取的算例,表明这种方法是有效的.     

含独立电阻组的有源C滤波器

本文提出一种可由运算放大器,电容比和电阻比实现的模拟有源滤波器,称为含独立电阻组的有源C滤波器。文中探讨了这种滤波器的可实现理论和实现方法,设计了具体电路,并给出了实验结果。     

模糊算法提取人类经验用于LTCC滤波器优化设计

将模糊算法用于LTCC滤波器的优化设计以达到快速设计的能力和设计的自动化。这种方法可以将专家信息和数值信息以if-then规则集的形式表示出来,通过建立模糊推理系统来模拟人的思维设计LTCC滤波器。特别是在设计参量多,各参量对滤波器的影响复杂时,这种方法可以有效设计LTCC滤波器。为了验证所提出方法的正确性,利用这种方法设计了一款LTCC滤波器。将所得的优化结果和测试结果进行了比较,验证了模糊算法用于LTCC滤波器设计的有效性和正确性。     

FIR窄带滤波器组在现代雷达中的实现和优化方法

提出了一种动目标检测滤波器组在FPGA中的设计方法,给出了FIR滤波器组的设计原则和滤波器的设计步骤,并给出一组滤波器的频响曲线,运用该滤波器对某雷达回波数据进行了处理。实现了滤波器组在FPGA中的应用,并就实现过程作出了优化。     

Preparation and Characterization of TaN ALD Precursors

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

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.     

Electronic Structure of Semiconductor Nanocrystals

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.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

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.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

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正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its