Simulating and modeling the breakdown voltage in a semi-insulating GaAs P+N junction diode

This work aims to determine the characteristic PN junction diode, subject to a reverse polarization, while I （breakdown voltage） of the inverse current in a GaAs specifying the parameters that influence the breakdown voltage of the diode. In this work, we simulated the behavior of the ionization phenomenon by impact breakdown by avalanche of the PN junctions, subject to an inverse polarization. We will take into account both the trapping model in a stationary regime in the P＋N structure using like material of basis the Ⅲ-Ⅴ compounds and mainly the GaAs semi-insulating in which the deep centers have in important densities. We are talking about the model of trapping in the space charge region （SCR） and that is the trap density donor and acceptor states. The carrier crossing the space charge region （SCR） of W thickness creates N electron-hole pairs： for every created pair, the electron and the hole are swept quickly by the electric field, each in an opposite direction, which comes back, according to an already accepted reasoning, to the crossing of the space charge region （SCR） by an electron or a hole. So the even N pair created by the initial particle provoke N2 ionizations and so forth. The study of the physical and electrical behaviour of semiconductors is based on the influence of the presence of deep centers on the characteristic I（V） current-tension, which requires the calculation of the electrostatic potential, the electric field, the integral of ionization, the density of the states traps, the diffusion current of minority in the regions （1） and （3）, the current thermal generation in the region （2）, the leakage current in the surface, and the breakdown voltage.     

一种用于无线接收机的噪声整形可重构复数带通/低通滤波器的设计

A reconfigurable complex band-pass （CBP）/low-pass （LP） active-RC filter with a noise-shaping technique for wireless receivers is presented. Its bandwidth is reconfigurable among 500 kHz, 1 MHz and 4 MHz in LP mode and 1 MHz, 2 MHz and 8 MHz in CBP mode with 3 MHz center frequency. The Op-Amps used in the filter are realized in cell arrays in order to obtain scalable power consumption among the different operation modes. Furthermore, the filter can be configured into the 1st order, 2nd order or 3rd order mode, thus achieving a flexible filtering property. The noise-shaping technique is introduced to suppress the flicker noise contribution. The filter has been implemented in 180 nm CMOS and consumes less than 3 mA in the 3rd 8 MHz-bandwidth CBP mode. The spot noise at 100 Hz can be reduced by 14.4 dB at most with the introduced noise-shaping technique.     

网络安全防护建设及优化的探讨与实践

根据桂林供电局网络安全防护现状,为完善桂林供电局办公局域网的网络安全防护体系,讨论并实践在桂林供电局网络拓扑图中的服务器区汇聚层部署入侵检测系统,对来自不同安全域的攻击进行检测及防护。     

主观评估模型在计算机衍生设计中的应用

在计算机辅助设计(CAD)的过程中,用户的主观感受和想法对设计结果有时会有决定性的影响,文章针对用户的主观评估特征构建了一种新的用户评估模型,该模型在传统的三维评价的基础上增加用户的主观评估维度,有效的提高了交互式设计的效果。     

一种并联有源电力滤波器的复合控制方法研究

在采用并联有源电力滤波器来消除电网谐波时,由于其滤波器的检测精度、指令电流计算延时等原因,一般的控制方法很难达到理想的滤波效果。因此,本文提出了基于常规PI控制和重复控制的复合控制方法,能使系统获得很好的静态性能和动态性能。仿真实验表明,这种控制方法实现相对比较简单,在响应速度和控制精度上都具有一定的优势,且能有效地对...     

怎样用SDA5000型数字电视分析仪测试双向放大器的反向插入损耗

介绍了SDA5000数字电视分析仪和漳州广电双向网络的改造方案,并简单地阐述了双向放大器的概念。介绍了SDA5000数字电视分析仪3个接口的作用,结合实际案例说明怎样用SDA5000数字电视分析仪测试双向放大器的插入损耗。     

基于局部特征匹配的目标跟踪研究

针对目标跟踪中的特征提取和匹配问题进行分析,提出了一种基于局部特征匹配的目标跟踪方法,该算法基于Shape Context进行特征提取。首先,对现有特征提取算法进行简单介绍,并详细介绍Shape Context的基本思想,基于此提出基于局部特征的跟踪算法。其次,详细阐述了目标跟踪算法：采用目标点的χ2-test直方图距...     

分布式并网发电系统孤岛检测方法综述

分布式发电系统并网运行时处于孤岛状态会对设备造成损坏,影响电力系统安全正常运行,严重时甚至可能会威肋到线路检修人员的人身安全.因此,对分布式发电系统孤岛检测方法的研究具有现实意义.本文综述了分布式并网发电系统孤岛检测的基本方法,并对其进行分类,最后对该领域的研究方向作出了展望.     

“差异化”高效网优方法的系统性应用

＂差异化＂优化思路以实现高效网优为目标,是基于现阶段无线网优工作特点而提出来的创新性优化思路,在完成其优化探索并在现网取得良好实践效果的基础上,经进一步对其系统性应用进行深入研究并历经实践检验,从而总结出可操作性较高的系统性优化方法。文章将实践经验与相关理论体系进行了有机结合,并重在对实际问题的有效解决,对相关优化工作...     

基于三维比例导引的舰空导弹协同杀伤区研究

介绍了舰空导弹杀伤区的基本概念,杀伤区可分为垂直杀伤区和水平杀伤区。由导弹速度可在垂直平面和水平平面进行矢量分解,引出三维比例导引弹道的方法,并利用此方法进行了单舰和双舰协同制导两种情况下弹目遭遇过程的仿真验证。仿真结果表明,协同制导可大大提高舰空导弹的低空杀伤远界,有效提高舰空导弹的作战效能。