共查询到19条相似文献,搜索用时 203 毫秒
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针对现代通信电源中广泛应用的开关电源中存在的传导干扰,提出了共模,差模噪声源模型及共模,差模噪声的预估方法,并阐述了电源滤波器插入损耗的计算方法,上述理论对电源电磁干扰滤波器的设计,选用具有直接的指导意义。 相似文献
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传导发射是电磁兼容设计中的重要问题之一。为了满足标准中对传导发射限制的要求,通常使用EMI滤波器来抑制电子产品产生的传导噪声。快速选择或者设计一个满足需要的滤波器是解决问题的关键。传导噪声分析技术包括共模噪声、差模噪声分析,共模阻抗、差模阻抗分析,这是滤波器设计的基础。 相似文献
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共模扼流圈是EMI滤波器的关键组件,主要用于传导干扰中的共模电流抑制。为了便于EMI滤波器抗干扰特性的仿真研究,提出了一种共模扼流圈的高频特性建模方法。首先,利用矢量网络分析仪测量共模扼流圈的共模与差模阻抗数据。然后,使用自组织迁移算法分频段处理共模扼流圈的阻抗数据,提取出仿真模型的RLC参数,结果表明利用算法分频段处理阻抗数据的方法,既使得所建立高频模型具有较高的精确度,也降低了对高性能计算机需求。最后,对一款共模扼流圈高频特性进行了建模,并通过仿真与实测的阻抗数据对比,验证了建模方法的有效性,为EMI滤波器的仿真与设计提供了参考。 相似文献
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简要介绍了共模、差模及非对称的测试电路,但都无法精准测量 EMI 滤波器的插入损耗。因此提出一种基于共差模分离器的测量电路,来精准测量插入损耗,并进行了实验验证及分析。该方案弥补了GB/T 7343-2017中测试方法的不足,并为滤波器内部电路存在的漏感现象、分布参数等对插入损耗的影响提供了测量方法。 相似文献
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Teck Beng Lim Lei Zhu 《Microwave and Wireless Components Letters, IEEE》2009,19(10):632-634
A differential-mode wideband bandpass filter (BPF) on microstrip line is proposed with good common-mode suppression. A four port two stage branch-line differential-mode BPF is first designed. Then, open circuited stubs are attached to the middle of two of the vertical branches. As such, its two-port bisection becomes a bandpass or bandstop filtering topology under differental- or common-mode excitations, respectively. The lengths and widths of these stubs can be properly adjusted to produce a highly attenuated and widened stopband under the common-mode operation. Finally, a wideband differential-mode BPF is designed and fabricated. The predicted and measured performances are in good agreement with each other, showing good common-mode suppression with an insertion loss higher than 20 dB over the differential-mode passband with a fractional bandwidth of 65%. 相似文献
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Hockanson D.M. Drewniak J.L. Hubing T.H. Van Doren T.P. Fei Sha Wilhelm M.J. 《Electromagnetic Compatibility, IEEE Transactions on》1996,38(4):557-566
Fundamental EMI source mechanisms leading to common-mode radiation from printed circuit boards with attached cables are presented in this paper. Two primary EMI source mechanisms have been identified: one associated with a differential-mode voltage and another associated with a differential-mode current, both of which result in a common-mode current on an attached cable. These mechanisms can he used to relate printed circuit layout geometries to EMI sources. The two mechanisms are demonstrated through numerical and experimental results, and an example from a production printed-circuit design is presented 相似文献
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A device is developed to decipher common-mode and differential-mode noise from a conducted EMI noise measurement. This device is a useful tool for power supply circuit noise diagnosis and line filter design 相似文献
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Meng J. Ma W. Pan Q. Zhao Z. Zhang L. 《Industrial Electronics, IEEE Transactions on》2006,53(6):1853-1861
In this paper, a general lumped circuit modeling method is proposed to describe the conducted electromagnetic interference (EMI) coupling mechanism for the switching power converters. The EMI characteristics of the converters can be analytically deduced from a circuit theoretical viewpoint. The shunt and series impedance insertion method is introduced to identify the differential-mode (DM) and common-mode (CM) noise impedances and voltage sources. The procedure of parameters estimation for the noise models comprises several simple measurements and is convenient to be implemented. Experimental illustrations are also included to verify the validity of the proposed method. Comparison between the measured and predicted results shows that the EMI modeling method can provide adequate prediction of the EMI feature for power-switching converters 相似文献
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论文主要讨论了电子设备中电磁辐射的机理及其设备中的干扰源,同时,对电路板上的差模辐射和共模辐射进行了讨论,得出共模辐射是产生电磁干扰的主要方式。在此基础上,论文进一步讨论了如何根据电路的辐射特性,提取出相应的辐射源,从而在电子设备仿真过程中建立相应的等效模型。 相似文献
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一些学者对双绞线电磁干扰进行研究,建立了精确的干扰模型,但并不适合工程应用.为此根据电磁兼容优势效应理论,推导出双绞线传导干扰主要由差模电流引起,辐射干扰主要由共模电流引起.分别利用广义二端口网络模型和电流元分析方法建立双绞线串扰和辐射的简化模型,从而有效估算双绞线串扰电压和对外辐射场的大小,最后给出滤波连接器的选择方法,为工程人员采取有效措施抑制互连设备电磁干扰提供了理论帮助. 相似文献
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提出了一种基于多模环形谐振器实现的平衡式带通滤波器, 其主要由加载了电阻和短路枝节的环形谐振器和两对平衡端口构成.所提出的滤波器能够以单个谐振器获得差模的双模响应, 并且具有结构简单, 共模抑制高, 带宽可进行有限控制(4% ~ 9%)的优点.为验证理论预期的可实现性, 在RO4003C基板上设计了一个工作在1.87 GHz的平衡式带通滤波器.实验结果表明该滤波器的20-dB阻抗匹配带宽为8.9%, 中心频率处的插入损耗为0.86 dB, 在1 ~ 3 GHz频率范围内的共模抑制大于30 dB. 相似文献