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提出了三种新的单ＣＣⅡ电流滤波器双二次结构，可以实现二阶低通、高通、带通、全通、陷波等电流模式滤波器，在所有三种结构中，ＣＣⅡ外接的无源ＲＣ元件不超过５个，由于采用ＣＣⅡ的Ｚ端以高阻抗方式输出，这些电流模式双二阶滤波节可以直接相互级联起来构成高阶滤波电路，而不需另加ＣＣⅡ隔离级，电路结构简单，无源和有源元件灵敏度均较低。 相似文献
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基于多输出端电流传送器（MOCC）的电流模式滤波器 总被引：1，自引：0，他引：1
提出了用ＭＯＣＣ器件实现双二阶和一阶函数的电流模式滤波器新电路．仅使用３个ＭＯＣＣ器件、３个接地电阻和３个接地电容,选择电路三个输入端口不同的输入信号的组合,不仅在Ｉ０２输出端能实现低通、高通、带通、陷波和全通五种基本的二阶滤波功能,而且在Ｉ０１端能同时得到一阶低通、高通、全通滤波函数,比ＣｈａｎｇＣＭ和ＣｈｅｎｇＰＣ所提电路结构简单,且功能更完善．为了验证理论分析的正确性,对二阶低通、高通、带通、陷波和全通及一阶低通、高通、全通滤波器均进行了计算机仿真．所提电路不仅ω０和Ｑ值可调而且具有无源灵敏度低的特点． 相似文献
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提出了一种新的多级电流模式双二阶滤波器通用结构，可获得电流模式二阶高通、低通、带通、全通和陷波滤波功能。该结构中的核心电路可集成在一起，仅需外接几只可调电阻便可以实现Ｑ、ω０和Ｇ的独立调节，这种滤波结构具有较高的输出阻抗和电流滤波增益，元件灵敏度较低。文章还给出了这种结构的简化模型和设计示例。 相似文献
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通过比较配电网中性点的几种接地方式，分析了中性点经消弧线圈接地方式可以限制接地短路电流的工作原理．提出选择消弧线圈的基本要求。 相似文献
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文章设计了一种基于CMOS第二代电流控制传输器(CCCIIs)实现的电调谐电流模式多功能滤波器。该滤波器电路仅由四个CCCIIs和两个接地电容组成。通过选择合适的输入和输出端,就能实现低通、高通、带通、带阻和全通五种滤波。此外,不需元件匹配条件,只需改变CCCIIs的直流偏置电流Ib,就可以独立调节滤波器的固有频率wo和品质因数Q,且具有较低的有源和无源灵敏度。采用TSMC0.18um CMOS工艺参数,进行Hspice仿真证实了所设计的电路是正确的。 相似文献
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本文论述了低压系统接地故障及其成因和几种常用的接地方式,阐明了造成接地故障引发火灾的原因,提出了接地故障引发火灾的防范措施。 相似文献
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为防止人体间接触电以及配电线路由于各种原因而引起设备损坏、火灾等事故,保证设备和线路的热稳定性,我国现行的电气设计、施工等相关规范都提出了在低压配电线路中需设置接地故障保护装置。在国家标准GB50054-95《低压配电设计规范》[1]第4.4.10条明确指出了采用接地故障保护的两种方法：零序电流保护与剩余电流保护（亦称漏电电流保护）。这两种电流保护的基本工作原理相同,但适用范围、安装等要求却有所不同。 相似文献
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我国的配电网电压等级通常为35KV、10KV以及6KV,针对目前配电网拓扑结构的特点,结合电网发生不对称接地故障后的故障特征,本文给出了一种基于综合信息融合的故障选线方法,在引入有功分量、零序电流以及五次谐波分量的背景下,给出了各种方法的权重分配方案。使用MATLAB仿真10KV配电网拓扑结构,对本文提出的选线方案进行了模拟,结果表明该方法受接地电阻、故障初相角的影响较小,选线结果准确。 相似文献
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In this paper, we consider the passive network synthesis problem of biquadratic impedances with at most four elements, motivated by the passive mechanical control. In order to solve this problem, a necessary and sufficient realizability condition for no more than three elements is obtained by some topological properties derived previously. Furthermore, the constraints on the possible realizations are used to derive the networks which can cover all the cases, and they are classified as several quartets. Through investigating one of the networks in each quartet, we obtain a necessary and sufficient condition for any biquadratic impedance to be realizable with at most four elements. Finally, the interlocking conditions are illustrated graphically, and numerical examples are given. 相似文献
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Statistical sensitivity measures for gain and phase functions of high Q active networks are studied. Explicit formulas for the sensitivity measures of second-order active RC networks are presented. The formulas obtained are shown to be simple and can be readily calculated for various high Q active RC filters. General formulation of the sensitivity measure for multiple-loop feedback active networks, which use high Q biquadratic active RC networks, is also given. 相似文献
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A new active RC biquadratic section using three operational amplifiers (op. amps) and capable of realizing high Q at high frequencies is presented. The circuit has low-sensitivity to variations in both the passive components and the op. amp gain-bandwidth products (GB). Compared to some existing circuits which require well-matched op. amps to achieve low sensitivity to GB, the proposed circuit has the important advantage of being insensitive to GB variations even if the op. amps are non-identical. The influence of the finite open loop d.c. gain and finite GB of the op. amps on the proposed design is examined. The new realization is then compared to those available in the literature, such as the circuits due to Kerwin–Huelsman–Newcomb, Akerberg–Mossberg, Mikhael–Bhattacharyya, Tarmy–Ghausi, and Wilson–Bedri–Bowron. Finally, some experimental results are provided to verify the theory. 相似文献
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New and systematic procedures are presented for realizing sampled data filter (SDF) functions using switched capacitors (SCs) and unity gain amplifiers (UGAs). The procedures are attractive and simple to implement. Any SDF, recursive or non-recursive and of any order, can be realized using the methods presented. The designs of biquadratic SDFs is discussed in detail. The resulting realizations possess the property that the numerator and denominator coefficients of the SDF functions can be controlled by independent capacitance ratios. This makes the filters attractive for adaptive applications. The sensitivity properties of the resulting filters are analyzed and guidelines given for obtaining low sensitivity realizations. A method is also suggested to make the filters relatively insensitive to the parasitic capacitances in the circuit. Finally, a step by step procedure, easily implemented in a computer, is given. Starting from the given analog filter specifications, the method yields a design that has very low sensitivity, uses minimum total capacitance and is tolerant of the various parasitic capacitances in the circuit. Experimental results show very good agreement with the theoretical analysis. 相似文献
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企业实施知识管理的误区和对策 总被引：2，自引：0，他引：2
知识管理是中国企业在知识经济时代的必然选择。从知识与信息的概念入手，剖析知识与信息，知识管理与信息管理的关系，指出知识管理不是信息管理，其核心是人力资源管理，其内容是知识资本，其关键是知识创新。实施知识管理，要积极促进知识共享机制的形成，设立CKO职位，创建知识创新的激励机制。 相似文献
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IMS是第三代移动通信伙伴提出的支持IP多媒体业务的子系统。IMS具有接入无关性以及标准开放的业务控制接口等特点。IMS提供了业务融合的基础,它基于IP技术同时支持语音、数据和多媒体业务等。IMS提供了业务融合的基础,它基于IP技术同时支持语音、数据和多媒体业务等。PoC业务是在IMS上实现的一种即时通信业务,其简单方便,通信快捷、即按即说、群组通话的特点使其成为移动增值业最有前景的应用之一。本文描述了一个基于IMS的PoC业务仿真系统的设计与实现。本文首先介绍了IMS、SIP和PoC业务等相关背景知识,然后提出一种设计与实现方案。 相似文献
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<正>A current bleeding CMOS mixer with complementary transconductance stage is presented in this paper.The conversion gain of the mixer is increased and the flick noise of the mixer is reduced by inserting the PMOS to form current bleeding circuit in Gilbert mixer.The circuit is designed through SMIC 0.18um CMOS process,the LO frequency is 1.571GHz,RF frequency is 1.575GHz,simulation results show the conversion gain of the mixer is 18.5 dB,SSB NF is about 9.59dB,and third-order input intercept point(IIP3) is-4.6dBm.The mixer consumes 7.8 mA at 1.8 V power supply and the size of the whole layout is 0.73mm×0.68 mm. 相似文献