混合动力电动汽车逆变系统中驱动高达600A—IGBT用的一种600V高压半桥式栅极驱动器集成电路

本文研制了一种600V高压半桥式、用于驱动IGBT栅极的集成电路（IC）。本文将先介绍基于监测IGBT传感电流的短路保护功能，然后介绍电平下移功能。之后，还将讨论另一种我们研制的短路保护功能电路，它通过对集电极和栅极的监测实现对IGBT的短路保护。本文中的IC最多可以驱动带有几个外部部件的600A／600V等级IGBT。本电路不仅适用于工业逆变器，而且适用于混合动力电动汽车。     

A Neural Network Method for Traffic Dispersion

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｒａｆｉｃｄｉｓｐｅｒｓｉｏｎ［１］，ｗｈｉｃｈｍｅａｎｓｔｈｅｔｒａｆｉｃｉｓｄｉｓｔｒｉｂｕｔｅｄｏｖｅｒｍｕｌｔｉｐｌｅｐａｔｈｓａｎｄｔｒａｎｓｍｉｔｅｄｉｎｐａｒａｌｅｌ，ｉｓｕｓｅｄｔｏｉｍｐｒｏｖｅｔｈｅｎｅ...     

Fast Frequency Offset Acquisition and Accurate Tracking in OFDM Systems

1　IntroductionOrthogonalFrequencyDivisionMultiplexing(OFDM )isaneffectivetransmissionschemetocombatmultipathfading[1～ 2 ,1 7] .Byinsertingaguardintervalbetweensymbolblockscalledcyclicprefix,theInter SymbolInterference (ISI)canbemitigated .OFDMisadoptedasthemodulationschemeforaDigitalAudioBroadcasting (DAB)sys tem[3] andAsymmetryDigitalSubscriberLoop(ADSL) [4] andisalso proposedastheterrestrialHDTVtransportinEurope[5] .OFDMsystemisverysensitivetocarrierfre quencyoffset.Manymet…     

光伏系统用于漏电流测量的霍尔闭环传感器设计

基于闭环磁通门技术的传感器广泛应用在测量大电流中的小剩余电流以及噪声共模电流。这类传感器的精度以及对大电流的隔离能力使之成为漏电流检测的最优方案,但通常缺点是成本昂贵且体积庞大。本文介绍了一种新型小尺寸且利用霍尔闭环技术对太阳能系统中的漏电流进行测量的传感器:新一代的LDSR产品。     

带有阶梯缓变集电区的InP/InGaAs/InP DHBT材料研究

设计并生长了一种新的InP/InGaAs/InP DHBT结构材料,采用在基区和集电区之间插入两层不同禁带宽度的InGaAsP四元系材料的阶梯缓变集电结结构,以解决InP/InGaAs/InP DHBT集电结导带尖峰的电子阻挡效应问题。采用气态源分子束外延(GSMBE)技术,通过优化生长条件,获得了高质量的InP、InGaAs以及与InP晶格相匹配的不同禁带宽度的InGaAsP外延材料。在此基础上,成功地生长出带有阶梯缓变集电区结构的InP基DHBT结构材料。     

A study of Reduced-Rank stap

This paper starts with the discussion of the principle of Reduced-Rank (RR) Space-Time Adaptive Processing (STAP). It is followed by a dedication of the upper bound performance of all eigen-based RR methods provided by Cross Spectral Method (CSM) under the condition of a given processor rank and an identical secondary sample size. A performance comparison between two RR STAP processors with prefixed structure and CSM is performed by the means of simulations. It is shown that the performance of time pre-filtering followed by jointly localized STAP structure (i.e. 3DT-SAP) is very close to the upper bound and thereby it is an effective RR approach.     

BER Performance of Frequency Domain Differential Demodulation OFDM in Flat Fading Channel

A closed form expression for the bit error rate (BER) performance of frequency domaindifferential demodulation(FDDD) for orthogonal frequency division multiplexing system in flat fadingchannel is derived.The performance is evaluated by computer simulation and compared with the timedomain differential demodulation(TDDD).The results indicate that the performance of FDDD is betterthan that of TDDD,and the lower band of BER in the former is lower than that of the latter.     

The Integrated Control-Mechanism in ATM-Based Networks

1 Introduction Network survivability has become a critical issue in telecommunication networks owing to the increase of social dependence on communication systems and the growing importance of information. Fast restoration from a network failure has been …     

RAPID CODEBOOK SEARCH ALGORITHM FOR SAR RAW DATA COMPRESSION

This paper presents a simple but eifective algorithm to speed up the codebook search in a vector quantization scheme of SAR raw data when a minimum square error(MSE) criterion is used. A considerable reduction in the number of operations is achieved.     

多路输入多路输出雷达：性能问题

多路输入多路输出技术的应用为多基地雷达提供了很多优点，包括改进的分辨率和灵敏度。取决于雷达的操作方式、阵面设计以及环境，这些优点可能或者不可能显著地表现出来。在本文中论述了一个地面动目标指示（GMTI）雷达探测的简单分析模型，并将预测情况与模拟情况进行了比较。对传统的单一输入多路输出（SIMO）和MIMOGMTI雷达在最小探测速度、区域搜索率和阵面副瓣方面进行了比较。确定了MIMO雷达的最佳波形互相关矩阵，提出了不同的性能标准。最后，改进了MIMO阵面的均衡采样虚拟孔径的范围。