屏蔽与接地技术中值得注意的几个问题

屏蔽线信号传输线路被广泛应用在计算机网络系统和有线电视系统中,它既可防止被干扰,也可以防止对外辐射造成干扰。本文通过对几种不同的“屏蔽接地”形式的比较,说明干扰电压的形成及解决方法。     

PCB基板材料用新型环氧树脂发展综述

文章对日本近年在高性能PCB基板材料用新型环氧树脂的品种、性能及应用进行了阐述。     

电能无线传输装置的补偿电路研究

介绍了基于电磁感应无线电能传输方式的主电路拓扑结构和工作原理。并对该传输方式的补偿电路进行了比较分析。搭建了仿真对补偿电路进行的比较和分析,最终给出了各自的使用场合。     

集成电路失效分析新技术

通过实例综述了目前国内集成电路失效分析技术的现状和发展方向。包括：无损失效分析技术、信号寻迹技术、二次效应技术、样品制备技术和背面失效定位技术,为进一步开展这方面的工作提供参考。     

迫弹激光引信用脉冲半导体激光电源的设计与应用

设计了适应于迫弹激光近炸引信的小体积、低电压、窄脉宽、高功率的脉冲半导体激光电源.采用电容充放电的模式,选用高速大功率MOSFET管作为开关,设计了相应的高速开关控制电路.激光电源模块的重复频率高达50kHz,常规热电池供电电压条件下的输出脉冲激光峰值功率为9W,光脉冲上升沿为4.2 ns,光脉宽为10 ns,为有效提...     

基于ZigBee技术的大坝安全监测系统设计

ZigBee技术是一种新兴的无线网络技术,它具有功耗低、速率低、距离短、时延短、网络容量大、安全性高等特点,主要用于近距离无线连接传输,在自动化监测和控制领域具有非常广泛的应用。根据ZigBee技术特点提出了无线监测系统的设计方案,使用英国Jennic公司生产的ZigBee模块进行了硬件电路的设计,经现场验证表明,将ZigBee技术应用于大坝安全监测系统中可以实现数据的无线双向传输,大大提升大坝安全的监测水平。     

基于考毕兹振荡器的宽带混沌电路设计

针对某些雷达、通信等系统在应用中对混沌信号频域带宽的要求,设计了一种基于考毕兹振荡器电路的宽带混沌信号发生器。该混沌信号产生电路由考毕兹振荡器为基本谐振电路、级联若干容阻串并联单元的选频网络构成,混沌信号的上下限频率分别由基本谐振电路和第一节容阻串并联网络参数决定,通带频谱的平坦性受其他级联选频网络影响。根据初步分析和仿真试验,该混沌电路组成结构简单,能够产生带宽超过60MHz较为平坦的宽带混沌信号。     

空间电子设备电路板可靠性可测试性设计检查

为了提高空间电子设备可靠性和可测试性设计的工作质量,采取在印制电路板生产前对其进行可靠性和可测试性设计检查的方法,可以提前在产品研发设计阶段发现可靠性和可测试性设计的不足,有针对性的加以改进,就能进一步提高产品质量与可靠性。列举了印制电路板可靠性可测试性设计检查要点,具有实际工程应用价值。     

全球挠性印制板的市场及其技术研究

介绍了2010年全球FPC发展的增长率和市场份额,分析了FPC的详细市场特点,概述了FPC的市场未来发展,同时,简述了2010年后全球FPC技术发展趋势。     

Non‐Geminate Recombination as the Primary Determinant of Open‐Circuit Voltage in Polythiophene:Fullerene Blend Solar Cells: an Analysis of the Influence of Device Processing Conditions

The physical origin of the open‐circuit voltage in bulk heterojunction solar cells is still not well understood. While significant evidence exists to indicate that the open‐circuit voltage is limited by the molecular orbital energies of the heterojunction components, it is clear that this picture is not sufficient to explain the significant variations which often occur between cells fabricated from the same heterojunction components. We present here an analysis of the variation in open‐circuit voltage between 0.4–0.65 V observed for a range of P3HT/PCBM solar cells where device deposition conditions, electrode structure, active‐layer thickness and device polarity are varied. The analysis quantifies non‐geminate recombination losses of dissociated carriers in these cells, measured under device operating conditions. It is found that at open‐circuit, losses due to non‐geminate recombination are sufficiently large that other loss pathways may effectively be neglected. Variations in open‐circuit voltage between different devices are shown to arise from differences in the rate coefficient for non‐geminate recombination, and from differences in the charge densities in the photoactive layer of the device. The origin of these differences is discussed, particularly with regard to variations in film microstructure. By separately quantifying these differences in rate coefficient and charge density, and by application of a simple physical model based upon the assumption that open‐circuit is reached when the flux of charge photogeneration is matched by the flux of non‐geminate recombination, we are able to calculate correctly the open‐circuit voltage for all the cells studied to within an accuracy of ±5 mV.