一种简易的音频周期性干扰抑制电路

介绍了一种简易而效果明显的音频周期性干扰抑制电路的设计思想，电路组成，工作原理和使用方法。     

一种与VLSI技术兼容的新型三维集成射频干扰滤波器

基于双π型电磁干扰滤波器(EMIF)的电路结构，借鉴集成电路超微细加工技术，提出了与等平面超大规模集成电路工艺完全兼容的一种新型三维集成射频干扰滤波器电路；简要介绍了该电路的绝缘层上金属薄膜三维集成制造方法，建立了电路传递函数模型，并进行了简要分析。该电路可用于制作适合未来电子系统高频化、小型化、轻型化和片式化信号处理的RF片上系统。     

电磁炉EMI滤波器的设计与应用

当电路中有电压存在时,在所有带电的元器件周围都会产生电场,当电路中有电流流过的时候,在所有载流体的周围都存在磁场,所有的电子和电气设备都是潜在的电磁干扰(EMI)源.本文在电磁干扰未到达被干扰设备前,根据其传播的特点,采用各种手段将传播切断或削弱,达到抑制干扰的目的.干扰经导线直接传导耦合到电路中是最常见的.抑制由导线直接传导的干扰,主要措施是串接滤波器.     

印制板的抗干扰设计

首先分析了电磁干扰的产生机理并对其进行了分类.针对电磁干扰产生的原因,提出了相应抗干扰设计的措施.通过阐述印制电路板(PCB)的布线方法与原则、电源线与地线的设计方法、抗扰器件的正确运用、合理布置元器件及板间线的配线原则,从而在实际应用中达到减少或消除电路印制板设计中常见的干扰,提高设备的可靠性与电磁兼容性.     

Pcb电磁兼容的设计研究

印制线路板(PCB)是各器件和电路元件的支撑平面,它提供了器件和电路元件的电气连接,它是各种机电的基本组成部分。它的性能适当程度上影响电器的质量。随着电子设备的普及,各元器件之间的电磁干扰现象显得尤为突出,所以研究电磁兼容刻不容缓,在介绍电磁干扰源,传播途径,地线干扰的同时,从印制电路板的设计,隔离技术,电源干扰以及地线的设计等方面研究电磁兼容。     

如何克服数字电路里的干扰

一、抑制电子电路干扰基本对策 数字电路里的干扰,大体上是如下两种因素所致:(1)数字电路引起的电磁干扰;(2)数字电路内部的电子器件或是布线之间的电磁干扰。作为电路间电磁干扰的耦合通道便是天线,在电磁干扰里的     

多元红外导引头预处理陷波电路的设计与仿真

多元红外导引头为了对抗云团等大背景干扰,在预处理电路中加入了陷波器.利用Matlab进行仿真,分析了陷波器带宽对抗人工干扰和预处理电路时间响应常数造成的影响和加入陷波器后的使用效果.仿真结果表明陷波器的带宽越窄会使整个电路的时间常数变长,带宽越宽会使抗人工干扰时信号下沉.根据仿真结果设计了顸处理陷波电路,经内外场试验该电路在抗云团等大背景干扰时,大大降低了背景噪声的幅值,提高了信噪比,在目标脉冲信号提取及抗人工干扰性能方面表现出了良好的性能.     

Sherwood(狮龙)P-965/A-965 7.2声道前后级环绕声放大器

采用前后级分体式设计的放大器，其优点人所共知：除了机内空间宽裕，可以让设计师尽可能地发挥、使用质量更优秀的元器件外，易受电磁干扰的前级放大电路和易产生电磁干扰的后级电路相互分离，也可以进一步提高声音的纯净度。所以，前后级设计的放大器一般声音都较为出色，输出功率也比较大。但是，前后级的设计往往要更复杂一些，而且制造成本也更高，所以大多用在Hi-End级别的立体声放大器上面。那么，多声道放大器有前后级分离的设计D-57当然有!但是由于放大通道增加、电路增多，所以前后级多声道放大器的设计和制造都较同档次的立体声放大器更难一些；     

高速放大器的应用电路

新工艺和设计的进步,已研制出了廉价的、精密的和实用的高速放大器。我们可以利用它的高速设计各种应用电路,这些电路包括DAC的电流/电压转换器、视频放大器和功率放大器等。提供了具体的应用电路及其电路工作原理。     

两相两重斩波器主电路电磁兼容设计与测试研究

分析了两相两重斩波器主电路产生电磁干扰的来源和机理,给出了两相两重斩波器电磁兼容设计采取的措施,提出了抑制传导干扰的主要设计方法,对电磁兼容测试结果进行了分析,测试结果证明论述的正确性。     

Development of the readout system for waveguide multilayer optical card

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.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

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.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

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.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

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.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

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.     

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.