光纤传输表面电流探头的设计与校准

本文介绍了一种在强电磁场环境中用于检测表面电流强度的光纤传输表面电流探头。采用光纤代替传统的电缆传输,对强电磁场有很好的抗干扰作用,同时也大大减少了对周围空间场的扰乱。其核心的信号处理环节采用直接强度调制式光纤通信,即采用射频晶体管做前级放大,将电压信号转换为电流信号,对光电器件进行直接光强调制。该系统动态范同大,非线性失真小,带宽达到5～120MHz,最大可测试电流为4A。文中给出了光纤传输表面电流探头的校准测试实例以及传输阻抗曲线。     

低频干扰电流探头中磁芯材料的选择对其检测性能的影响

本文通过分别对采用铁氧体和铁基非晶合金为磁芯材料的低频干扰电流探头的测试性能的比较分析,讨论了由于铁基非晶合金自身良好的磁性能,使得电流探头在测试低频干扰电流时的测试性能大大提高,从而对于解决目前国内所设计制作的干扰电流探头在测试低频干扰电流时探头灵敏度低、测试不准确这一问题提供了实验依据。     

表面电流探头校准装置的设计及应用

文章利用保角变换法对非无限长、变截面平行板传输线的特性阻抗进行了分析计算.根据分析结果设计了表面电流探头的校准装置.文中给出了设计的理论公式,试验数据和图表.     

基于容性耦合夹的汽车电子传导骚扰测试方法研究

目前在汽车电子电磁兼容测试领域,普遍采用电压法和电流探头法对零部件/模块的传导发射进行测量.近年来,著名德系车厂提出了一种全新的基于容性耦合夹的传导骚扰测试方法(CV-Test).本文对这一新的测试方法进行了介绍,同时给出插入损耗的校准方法.采用基于容性耦合夹的方法进行传导骚扰的测试正成为汽车电子电磁兼容测试领域一种新的动向,逐步被车企认可和采用,具有较好的应用前景.     

电流探头法测量不对称模式传导发射的不确定度分析

介绍电流探头的应用场景，详细分析电流探头的结构、测试原理和技术指标，以实验室的电流探头(型号EZ-17)为例，对使用电流探头测量不对称模式传导发射的不确定度分量进行整理和分析，对各分量分别进行评定，最后汇总得到该项目的扩展不确定度，有利于提高使用电流探头进行传导发射测试的可靠性。     

表面电流探头的校准和应用

提出了在电磁兼容测量中应用的表面电流探头的校准方法，设计制作和实际应用。在这种方法中，平行板传输线被用来建立已知的，均匀的表面电流以确定表面电注探头的传输阻抗。文中提供了试验数据和图表，分析了测量的不确定性。     

测试系统中动态电流的检测原理和实现方法

本文介绍了在测试系统动态电流测试中将待测电流信号转化成电压信号,并对电压信号进行处理,实现测试系统中动态电流的自动检测,利用PSPICE软件对测试原理进行了验证,并给出了测试仿真波形图和原理说明。     

弧面电流探头传输阻抗的校准

利用内圆外方同轴传输线理论,提出弧面电流探头传输阻抗的校准方法.详细介绍了校准装置的设计制作、测试及校准应用.     

电流探头注入替代辐射场的电磁敏感度自动测试技术

本文主要论述了电流探头注入替代辐射场的电磁敏感度测试方法、可行性及采用通用计算机控制的自动测试系统的硬件组成、2软件实现方法和实际测试的可能性。     

城轨列车线缆传导发射的现场测试分析

介绍了测量列车牵引系统和辅助电源系统线缆上传导发射的现场测试方案.对测试布置、电流探头的选取进行了详细说明.并对测试要点、实验数据进行了分析.分析数据可知城轨列车动力电缆造成的干扰能量主要集中在1 MHz以下的频率段.     

Efficient analysis of electromagnetic radiation from microstrip antenna using volume-surface current contunuity method

The Volume-Surface Current Continuity Method (VSCCM) is presented to analyze electromagnetic radiation from microstrip antenna. The microstrip antenna is discretized into small triangular patches on conducting surface and tetrahedral volume cells in dielectric region. The Method of Moments (MoM) is applied to solve the integral equation. An equation contains the restriction relation between the volume and surface current coefficient is derived from the current continuity equation at those parts where the conducting surface is in contact with the dielectric material. A simple equivalent strip model is introduced in the treatment of the feeding probe in VSCCM. The VSCCM can reduce the unknowns required to be solved in MoM, as well as the condition number of the matrix equation. Numerical results are given to validate the accuracy and efficiency of this method.     

Symmetric Temperature Compensation for Photoelectric Coupling Current Transducer

The temperature characteristic of sensor probe at high-voltage side is anslyzed by using a photoelectric coupling current transducer.The principle of symmetric temperature compensation and the main idea of software design are proposed.The method increases measuring precision and has fairly great practicability.     

温度对碲镉汞光伏芯片I-V特性的影响

对室温工作的短波碲镉汞光伏芯片进行了步进温度烘烤实验。烘烤温度从60 ℃开始，步长为5 ℃，到120 ℃结束，每个温度下的烘烤时间一般为24 h。实验结果显示当烘烤温度达到95 ℃以上时，I-V测试结果中反偏部分的电流有明显增大。通过理论分析得到扩散电流和产生复合电流是实验芯片的主要电流机制；较高温度的烘烤在势垒区内产生大量的缺陷，从而降低芯片的少子寿命，使扩散电流增大；同时芯片表面钝化层内的缺陷数目也在温度作用下增加，引起芯片表面复合速度增加。     

Excitation of an Infinite Microstrip Line With a Vertical Coaxial Feed

An efficient method is presented for the analysis of a vertical coaxial probe excitation of an infinite microstrip line. The novel feature of the method is that it uses a semianalytical Green's function that is derived for current sources in the presence of the infinite microstrip line. Hence, in a method of moments approach, unknown currents need only be placed on the conducting probe feed and not on the infinite strip surface. The method also utilizes an attachment mode at the contact point between the probe and line so that the correct Kirchhoff condition is automatically satisfied. Once the surface current density on the probe is known, the surface current density on the strip conductor can be readily obtained using the Green's function of the background grounded substrate. The method is valid even at high frequency, where simple transmission line theory fails to account for effects such as the continuous-spectrum current that is excited on the line. After validating the method with various commercial software simulation packages, results are presented to study the fundamental behavior of the input impedance, probe current, and current launched on the microstrip line, and to examine the high-frequency behavior of these currents.      

Moment-method solution of the center-fed microstrip disk antennainvoking feed and edge current singularities

The problem of a microstrip disk antenna excited by a probe at its center is studied using a moment-method approach for the evaluation of the surface current on the disk. The novelty of the work is a careful treatment of the singular effects of the probe and of the disk edge on the surface current on the disk. This is done by including in a proper way an attachment-mode current and an edge current in the surface current on the disk. The inclusion of these two currents accelerates the convergence of the moment-method solution and enables the input impedance to be obtained in a broad frequency range, including the zero-frequency limit. The influence of the probe on the input impedance is taken into account in a correct and accurate way. A comparison between measured and computed results is given, and good agreement is obtained     

多晶硅有晶体管直流特性研究

研究了砷注入多晶硅发射极晶体管的直流特性,并与采用常规平面工艺制作的晶体管性能的进行比较。结果表明多晶硅发射极晶体管具有较高的发射效率,高的电流能力,改善了ＥＢ击穿和ＣＢ击穿,电流增益依赖于淀积多晶硅前的表面处理条件。     

不同电流密度对直流电镀填盲孔的影响研究

电镀填盲孔是HDI加工的一个重要工序。本文通过研究不同电流密度在不同电镀时间内的填孔行为,并尝试通过采用组合电流密度来提升电镀填盲孔效果,从而实现降低填孔镀铜量的目的。     

A nonstationary probe that is self-consistently negatively charged and embedded in plasma

The dynamics of ions in a plasma layer adjacent to the conducting surface of an electrically insulated negatively charged probe is studied. Exact self-consistent analytical solutions to the nonlinear system of equations of ion hydrodynamics are obtained. The solutions satisfy nonstationary boundary conditions on the probe’s surface. The intensity of the electric field and the velocity, concentration, and density of the ion current are found as functions of the initial position of a particle and the distance to the probe’s surface. The rate of change in the probe’s charge is determined and it is shown that, with time, the parameters of the system considered approach their asymptotical values. For a spherical probe, the time dependence of the ion-current density, i.e., the probe’s transient response (which is an analogue of the current—voltage characteristic of the Langmuir probe with a constant negative bias), is obtained.     

GaN基HEMT器件的表面陷阱电荷输运过程实验研究

基于特制的无台面AlGaN/GaN HEMT,设计了一种实验方法,用以研究AlGaN/GaN外延表面陷阱态间的电荷输运过程。经实验证实,在器件电流崩塌效应中,存在表面陷阱电荷输运,并确定了相关时间常数。针对应力后电流崩塌驰豫过程,实验监测到小于0.1 s和大于10 s两类时间常数,其中较大的常数对应于表面陷阱电荷的输运过程。此结论可望用于对AlGaN/GaNHEMT电流崩塌效应进一步的理论探索和相关的器件研究。