共查询到19条相似文献,搜索用时 234 毫秒
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通过研究超声相控阵探头阵元间串扰机理及串扰隔离方法提高近表面检测能力。 基于数值仿真技术分析了安装楔块
前后阵元间超声波串扰对检测信号及检测声场的影响,分析探头楔块对于隔离阵元间超声波串扰与近表面缺陷检测信号的作
用。 提出楔块优化方案,并通过试验方法对其进行验证。 结果显示,数值模型可直观显示阵元间的超声波串扰,提出的楔块优
化方案可将时域上的阵元间串扰信号与近表面检测信号相互隔离。 优化楔块后的相控阵探头可对深度 2 mm、直径 0. 3 mm 平
底孔进行成像检测,近表面缺陷检测能力显著提高。 相似文献
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梳理了数字电路封装串扰测试方法的发展历史,总结了串扰的影响因素。基于对业界串扰测试方法的分析,比较了各种方法间的区别和优缺点,分析了美军标MIL-STD-883K中串扰测试方法很少修订却长期存在的原因。明确了美军标及其他串扰测试方法的适用范围,提出了我国相应标准制修订方向的建议。测试结果表明,标准中的现有方法在评估串扰对整体电路影响方面手段有欠缺,需要结合电磁仿真对串扰影响做出整体评估,并利用实际测试对仿真结果进行校准,从而提高模拟的准确度,此方法可以在我国相应标准的制修订中加以采用。 相似文献
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板级互连线的串扰规律研究与仿真 总被引:2,自引:0,他引:2
串扰是高速电路板设计中干扰信号完整性的主要噪声之一;为有效地抑制串扰噪声,保证系统设计的功能正确,有必要分析串扰问题。针对实际PCB中互连线拓扑和串扰的特点,构建三线耦合均匀传输线模型,采用信号完整性仿真工具HyperLynx进行PCB布线前的LineSim串扰仿真,详细分析了高速PCB中多种因素:耦合长度、耦合间距、信号上升时间、介质厚度、端接等对近端和远端串扰宽度和幅值的影响;最后总结了串扰宽度及其幅值的变化规律,可有效的指导PCB设计中减小串扰噪声。 相似文献
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正交模变换器是在紧缩场测试中应用于平衡馈电网络的重要器件。设计了一种基于复合左右手传输线的正交模变换器,在分别以1.9GHz和2.6GHz为中心频率的2个频带内实现功能。测试结果表明:2个频带内的驻波比都在3以下,其中第2个频带内驻波比在1.5以下;相位差180°±2°;幅度不平度小于0.5dB。研究还发现电桥的存在可以改善驻波比,并且电桥的高度越低驻波比越低。 相似文献
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Takemi Watanabe Fujihiko Matsumoto Toshio Miyazawa Yasuaki Noguchi 《IEEJ Transactions on Electrical and Electronic Engineering》2009,4(6):742-749
Crosstalk analysis is getting more important for avoiding malfunction of circuits. In this paper, crosstalk analysis of parallel microstrip lines with a nonlinear capacitive load is described. A characteristic of the nonlinear capacitive load is changed by a rapidly change of an applied voltage of the load. The change of the characteristic induces a complicated reflected wave that causes complicated crosstalk. To simulate such crosstalk precisely, the dynamic C-V characteristic can be used. However, if the dynamic C-V characteristic is complicated, it takes a long time to simulate the crosstalk by using a conventional method. Thus, a simulation method using a recurrence formula is introduced. The recurrence formula is derived from a function of the dynamic C-V characteristic simply. The calculated results computed by using the introduced method agree with the measured crosstalk and the introduced method is superior in computation time to the conventional method. It is confirmed that the introduced method is effective in crosstalk simulation. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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随着晶体管制造尺寸的越来越小,集成密度的越来越高,耦合电容与电感之间所引起的相邻互连线间的干扰噪声成倍增加,对高速高密度纳米级超大规模集成电路造成极大危害。阐述了包括片上网络(Network-on-Chip,NoC)在内的高速互连电路串扰型故障的基本原理及串扰耦合模型,阐述了高速互连电路串扰型故障测试的主次因素机理等,并用HSPICE仿真验证了基于90nm和65nm的NoC参数下MA、MT故障模型中U型传输线线宽和线间距对串扰的影响。仿真结果表明,线间距越小,线间的高速互连串扰现象愈明显。 相似文献
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随着晶体管制造尺寸的越来越小,集成密度的越来越高,耦合电容与电感之间所引起的相邻互连线间的干扰噪声成倍增加,对高速高密度纳米级超大规模集成电路造成极大危害。基于分布式RLC耦合互连模型详细的模拟了金属互连线的延迟及串扰,对32nm CMOS工艺下的不同互连线尺寸进行模拟,仿真给出了在不同的厚度下延迟与串扰之间的关系,优化互连线的几何尺寸能有效的减小互连线的串扰噪声和延迟。结果表明:互连线宽W同互连线节距P之比在W/P=0.6时是获得最小时间延迟的最佳尺寸。 相似文献
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本文利用光子晶体带隙(PBG)结构的特点,将特殊设计的 PBG 结构应用于圆柱形微带贴片天线中。在同轴线馈电的圆柱形微带贴片天线的介质上蚀刻出按一定规律排列的 PBG 结构,并基于 HFSS 对特殊设计的 PGB 结构圆柱形微带贴片天线和普通的圆柱形微带贴片天线进行仿真和优化,仿真结果表明,按照一定规律排列的 PBG 结构可以有效抑制天线表面波的传播,明显提高圆柱形微带贴片天线的带宽和增益,有效改善圆柱形微带贴片天线的辐射方向图,实现天线性能的优化设计。 相似文献
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Tulasi Naga Jyothi Kolanti Vasundhara Patel Kerehalli Shankar Rao 《International Journal of Circuit Theory and Applications》2020,48(12):2041-2055
This paper presents an accurate structure for multilayer graphene nanoribbon (MLGNR) bundled interconnects to reduce the effects of crosstalk in ternary logic circuits. In the proposed structures, the signal line is surrounded by the shielding lines to reduce the crosstalk effects. The crosstalk effects such as noise peak, noise area, delay, and power consumptions are compared to effects produced by conventional methods. The impacts of process variation in the proposed structures are also presented. Additionally, the proposed MLGNR interconnect results are compared with the carbon nanotube interconnections. All the proposed circuits are implemented and simulated using HSPICE tool. The simulation results indicated that the passively shielded MLGNR interconnects provide lower crosstalk effects up to 47.7% and 69.4%, respectively, over the active and without shielded interconnects. 相似文献
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If two transmission lines such as microstrip lines are set in the neighborhood, a coupling or crosstalk phenomenon may be generated between them. When the coupling level is low, the phenomenon can be considered as a coupling of external fields by one transmission line to the other transmission line; a set of nonhomogeneous differential equations with regard to a line voltage and current holds approximately. The fields can be obtained by estimating vector potentials of currents on the line section and the terminals in terms of a terminal voltage and current of the line concerned. Thus, a solution to the equations can be obtained in expression of a four-port network. Estimation of the coupling between microstrip lines is made by applying the terminal conditions to the expression. To confirm the theory, an experiment has been conducted; the experimental results are in good agreement with the theory. © 1998 Scripta Technica, Electr Eng Jpn, 123(2): 8–15, 1998 相似文献
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In this paper, theoretical analysis of the input impedance of the two gap-coupled circular microstrip path antennas loaded with shorting post has been performed. The concept of coupled microstrip lines is applied to the gap-coupled microstrip antennas loaded with shorting post and using circuit theory approach the input impedance of the structure is calculated. The effect of mutual coupling between the radiating apertures has been taken into account. Simulated results are presented for input impedance of the gap-coupled circular microstrip patch antenna loaded with shorting post which supports the theoretical predictions. The simulation work has been performed using the method-of-moment based commercially available simulator IE3D. The comparison shows good agreement between simulated and numerically computed results. 相似文献