变频调速应用技术（五）——第三讲选好系统上变频（上）

本文介绍了选择变频器容量的有关问题，变频器外围器件的功能与选择，以及抗干扰问题等。     

Investigation of electromagnetic radiation induced by conducting wire of nanometer multi-quantum well device on InGaN LED

It is known that electromagnetic interference (EMI) has a negative effect upon the performance of electronic communication systems. The present study considers the case, where EMI is induced in an conducting wire (CW), and derives equations to establish the influence of the induced EMI on InGaN material of nanometer quantum well light-emitting diodes (LED). These equations are then verified experimentally. The present results indicate that the degree of influence of the EMI upon the InGaN LED device depends upon the interference power, the interference frequency, the induced power, the input resistance of the device, the inverse saturation currents, and the ideal factor of the LED. Moreover, the greater EMI amplitude and frequency, the greater deterioration I-V curves of the InGaN LED.     

A methodology for testing immunity of field programmable analog arrays to radiated electromagnetic field

Tests of field programmable analog arrays (FPAA) are required to assess tolerance to variations of components, due to aging, uncertainty, or external disturbances. The paper focuses on radiated electromagnetic energy as a cause for a possible faulty behavior: results show that input and output channels of the FPAA are affected by the presence of noise due to the coupling of the incident field with the board, and that the susceptibility profile depends on the configuration of the FPAA and the field’s polarization. Therefore, topology and electromagnetic characteristics of the board must be carefully designed. Moreover, the transfer function is susceptible to the incident field to a degree that depends on the configuration of the FPAA and the field’s amplitude and frequency. This limits application of FPAAs in critical applications like in the automotive and aerospace industry, where fields with large amplitudes are likely to be encountered during normal operation.     

A 3–5 GHz low-power high-speed radiated power tuning UWB transmitter

To satisfy the different radiated power requirements for the ultra-wideband (UWB) data transmitting in the implantable electronic devices or the wireless component interconnections, a novel low-power high-speed UWB transmitter with radiated power tuning was proposed. The tunable radiated power is achieved by a UWB RF buffer with a peak value controller. The designed low-complex narrow pulse generator and digital ring on–off VCO ensure a high speed transmitting. The low power is realized by using a subtractor to eliminate the base-band component from the output of the VCO and making the UWB RF buffer and the VCO operating in standby mode. The design was fabricated by a standard 0.18 μm CMOS technology. The test results show that the design can achieve maximum data-rate of 250 Mbps, frequency bandwidth from 3 to 5 GHz, radiated power tuning from −40 dBm to −60 dBm, low-power of 8 pJ/bit, and small circuit area of 0.18 mm².     

表面振动法测量汽油机表面辐射噪声

对基于表面振动测算汽油机辐射噪声的方法进行了研究,首先对该方法的理论基础和数学关系进行探究,并以此理论为基础设计试验及数据处理方法。然后对一台四缸汽油机进行了实验验证,测量得到了表面振动速度,估计计算出发动机整机声功率和各部件的噪声贡献。实验表明测算噪声结果准确度较高,证明该方法能可靠有效地测得汽油机的辐射噪声。     

电子束辐照交联电线中束下工艺的研究

将磁铁技术应用于电子束辐照交联电线电缆的束下工艺，一套传动设备以不同型式的磁铁，形成三种辐照方式，适应了全规格电线电缆的要求，芯线截面０．５－４００ｍｍ＾２含扇形线，线缆外径φ１ｍｍ－φ４０ｍｍ，最大可达φ６０ｍｍ。给出了能量选择公式，束流利用率和辐照均匀性的公式和分析。与实验结果相比较，两者较为符合。     

无线键盘辐射信号的频谱测试与分析

在微波暗室内利用高性能频谱分析仪对无线键盘工作时产生的辐射信号进行测试,获取无线键盘辐射信号的频谱数据,进行相应的频谱特性分析,找出其辐射的重点频段和特点,为分析按键信息还原提供技术帮助。     

带辐照改性聚丙烯填料的气升式内环流反应器处理废水的研究

应用高能射线辐照技术,在聚丙烯填料表面接枝丙烯酸单体进行改性。将此改性填料应用于气升式内环流反应器中,并对模拟生活废水进行间歇法和连续法处理。实验结果表明,该反应器运行稳定,适应浓度范围广,COD去除率较高,出水COD浓度波动小。     

ESD辐射场测试研究

测试一直是静电与电磁防护研究的瓶颈.针对ESD辐射场测试问题,提出了能量有效带宽和动态范围有效带宽的概念,并根据IEC61000-4-2标准规定的ESD电流波形,采用数值方法估算了ESD辐射场的带宽以及上升时间对带宽的影响.在此基础上成功研制了带宽为3.5Hz~1GHz(±1.5dB),动态范围60dB,测试灵敏度可调的ESD辐射场测试系统,并实际测试了IEC61000-4-2标准规定的水平和垂直耦合电场.     

液晶显示器辐射干扰对策

本文结合38cm(15英寸)的液晶显示器辐射干扰的试验情况,针对试验过程中出现的问题简单介绍了液晶显示器的辐射干扰的整改思路及整改情况.