A moment-method design procedure for an array of EMC dipoles

A design procedure based on a moment-method analysis is given for an array of microstrip dipoles electromagnetically coupled (EMC) to microstrip transmission lines. One of the key features of the design procedure is that only one pair of EMC dipoles needs to be analyzed at a time in order to develop the necessary coupling coefficients. These coupling coefficients allow for the complete analysis or design of the array, accounting for interactions between all of the EMC line-dipole pairs. One of the useful properties of the present formulation is that EMC dipole arrays can easily be designed for which the length and offset of each dipole are the same, which simplifies the array construction     

Simplified Macromodel of MTLs With Incident Fields (SiMMIF)

Electromagnetic compatibility (EMC) analysis of high-speed designs has become imperative due to rapidly increasing radio-frequency interference and emerging technological trends such as higher operating frequencies, denser layouts, and multifunction convergent products. In this paper, a simplified macromodel of multiconductor transmission lines (MTLs) exposed to incident fields is presented. The proposed formulation can also handle frequency dependence of resistance, capacitance, conductance, and inductance (RLGC) line parameters. The method employs the recently developed delay-extraction-based compact and passive MTL macromodel, while developing closed-form expressions for incident field analysis. An error bound for the proposed macromodel is also presented. The macromodel is simulation program with integrated circuit emphasis (SPICE) compatible and overcomes the mixed frequency/time simulation difficulties usually encountered during transient analysis, while guaranteeing the stability of the global transient simulation. The algorithm provides higher accuracy as well as significant speed gains for EMC analysis of transmission line networks as compared to the existing techniques.     

Time-domain finite difference and EMC study of hot carrier transport in GaAs on a picosecond scale

It is now possible to use optoelectronic techniques to generate and measure electrical waveforms with subpicosecond risetimes. Though experimental methods have become relatively advanced, simulation techniques for analyzing and modelling such ultrafast transients remain inexact and oversimplified. The simplifications commonly made while developing equivalent circuit models for the experimental structures, prevent accurate simulation of the electrical response during the picosecond regime. In order to obtain a better physical picture, it is essential to develop a more physical model for the microstrip circuits routinely used in such experiments. Furthermore, non-Ohmic transport behavior for the photogenerated carriers within the optoelectronic device also needs to be correctly incorporated. We address both the circuit and device response issues through a novel scheme which combines direct time domain solutions to Maxwell's equations with the ensemble Monte Carlo model for carrier transport. By coupling the electromagnetics with the EMC, we avoid having to make assumptions whose validity breaks down for picosecond transport.     

Spherical near-field facility for microwave coupling assessments inthe 100 MHz-6 GHz frequency range

This paper describes a spherical near-field facility set up at the Centre d'Etudes de Gramat (CEG) to perform low-power microwave coupling assessments. Specifically, this facility has been designed to determine the coupling cross section of a complex object. However, it can also be used for the characterization of any radiating system in electromagnetic compatibility (EMC) or high-power microwave (HPM) environments. The near-field approach is shown to be complementary and to offer increased flexibility when compared to other more conventional measurement techniques. More particularly, the use of a probe array in the upper part of the frequency band significantly speeds up the near-field measurement process. Consequently, broadband and multiparameter acquisitions can be performed within acceptable duration. The examples given in this paper provide a broad illustration of the capabilities of near-field techniques for EMC and HPM applications     

EMC测试中的电流注入技术

文章综述了在系统电磁兼容性(EMC)测试中替代直接辐照的电流注入技术的最新研究成果。电流注入技术主要有两种：大电流注入(BCI)和直接电流注入(DCI)。BCI技术主要用于辐射敏感度测试，尤其是测试电缆束对射频耦合的敏感度。DCI技术是一种用在高场强辐射场(HIRF)下系统级EMC安全裕度测试的新技术，研究的热点是其相对自由场辐照的有效性及等效关系。     

不均匀多导体传输线的瞬态分析

针对越来越严重的信号畸变和线间耦合问题,应用时域有限差分法（Finite Difference Time Domain,FDTD）建立了不均匀多导体传输线的仿真模型,并通过MATLAB编程对不均匀多导体传输线两端的电压响应进行了仿真分析.在此基础上,理论说明了各端口瞬态响应的波形特点.结果表明了时域有限差分法用于分析多导体传输系统电磁兼容问题的正确性和有效性,为电磁干扰的预测提供了有价值的参考信息.     

基于广义传输线方程的平行双导线电磁耦合分析

近地传输线系统的电磁耦合特性分析一直是通信电力系统电磁兼容分析中比较重要的一部分内容。主要对 双线传输线系统进行BLT 建模分析,在此模型中分析高度、半径参数对传输线上电流的影响,并且分析了传输线系 统在不同入射情况下的电流结果。计算结果物理意义明确,可供EMC 设计时参考。     

Circuit-Based Analysis of Electromagnetic Field Coupling With Nonuniform Transmission Lines

This paper presents a new algorithm for simulating electromagnetic (EM) field coupling with nonuniform multiconductor transmission lines in a circuit simulation environment. The proposed algorithm is based on the concept of passive model-order reduction, whereby an algorithmically developed passive reduced-order model, coupled with a set of equivalent sources representing the incident filed, are shown to accurately capture the behavior of the transmission line under EM excitation. The reduced-order model is developed independently from the particular shape of the incident field pulse, in the sense that, in constructing the model, one does not need prior knowledge about the waveform of the incident pulse of the EM field. In addition, it is also shown that the model developed can be used to simulate the transmission line in the absence of the EM field. The derived equivalent sources, representing the field coupling, are given directly in the time domain, thereby making simulation under nonlinear circuit terminations an easy task. Although the proposed work is aimed mainly at simulating nonuniform transmission lines, it can be applied to uniform lines as a special case. The proposed algorithm has been validated numerically with several examples.     

并行传输线共模泄漏的等效场-线耦合数值模型

针对并行传输线间感性和容性耦合计算问题,该文提出并行传输线等效场-线耦合亚网格时域有限差分(FDTD)数值模型,模型更适合非均匀介质等复杂情形的耦合串扰求解,且具有更为简洁的数值计算形式。利用该等效场-线耦合数值模型,对并行传输线间共模电磁信息泄漏进行模拟仿真和实验测试,时域模拟和频域实验结果均表明,该模型可以有效刻画并行传输线共模电磁信息泄漏发射特性。     

基于变换域和时域联合处理的雷达同频干扰抑制方法

针对舰艇编队情况下线性调频脉冲体制雷达间同频干扰的问题,该文提出一种分数阶傅里叶域滤波处理与时域反异步处理相结合的干扰抑制方法。通过分数阶傅里叶域自适应滤波对与目标回波信号调频率不同的干扰信号做抑制处理,同时根据分数阶傅里叶变换的可逆性,逆变换到时域后采用相邻周期反异步方法进一步消除与目标回波信号调频率相同或相近的同频干扰。仿真试验表明,该方法相对传统方法能够有效抑制与目标回波信号调频率不同的同频干扰,同时对于在时域与目标回波信号完全重合或部分重合的干扰信号也有较好的抑制效果,干扰抑制处理增益达到29 dB以上。该方法为提高同型雷达编队组网能力提供了设计参考。     

系统电磁兼容性问题预测实例

系统电磁兼容性预测不仅在方案阶段需要,在工程阶段仍然重要,是进行合理电磁兼容性设计,争取时间、减 少费用的有效手段。系统电磁兼容性预测可以使用专业软件进行仿真计算、分析,在特殊情下也可以采用工程简化方法 计算、分析,还可以用工程经验进行分析评估。在电磁兼容性预测计算、分析中,仿真软件一般考虑全面,简化方法计 算相对快捷,建立简化且与实际接近的干扰源模型、传输特性模型以及敏感度域值模型是计算、分析准确程度的关键。 本例中是用简化方法对实际系统电磁兼容性问题解决提供了理论依据,并进行了仿真和试验验证,结论一致。说明,除 了用专业仿真软件进行预测计算,用工程简化方法计算也会常常遇到;实际电磁兼容工作中系统预测是重要的并且不一 定非常复杂,供参考     

PCB design techniques for lowest-cost EMC compliance. 2

For pt.1 see ibid., vol.8, no. 4, p.185-94 (1999). Printed circuit boards (PCBs) are widely used in electronic equipment and systems. Application of good EMC (electromagnetic compatibility) practices to their design usually helps to achieve compliance with EMC regulations at much lower cost than alternative EMC measures at higher levels of integration, and also improves signal integrity. This paper discusses in detail techniques for improving the power supply of a PCB and using transmission lines     

圆波导壁上小孔耦合电磁能量分析

本文借助圆波导并矢格林函数 ,采用矩量法分析了任意平面波通过圆波导壁上小孔耦合到波导中的能量 ,计算了通过小孔的能量传输系数 ,该结果可用于复杂系统EMC预测。     

PCB design techniques for lowest-cost EMC compliance .1

Application of good EMC (electromagnetic compatibility) practices to the design of printed circuit boards (PCBs) usually helps to achieve the EMC performance required of equipment and systems at much lower cost than alternative EMC measures at higher levels of integration, such as whole-product shielding. EMC design is a complex topic, but the proven best EMC practices for generalised PCB layout can be fairly simply stated and grouped into five techniques, which interact with each other to give dramatic improvements in EMC performance. This paper discusses the techniques of circuit segregation, interface suppression and the use of ground and power planes     

基于PADS2004的高速PCB设计

在高速印刷电路板设计过程中,仅依靠个人经验布线,往往存在巨大的局限性,因而高速电路设计的仿真显示出越来越重要的地位。借助仿真软件,通过对高速信号线进行布局布线前仿真和布局布线后仿真,可以发现和解决信号完整性、串扰、EMC等问题。本文主要介绍了使用PADS2004/hyperLynx软件进行印刷电路板的仿真,通过对高速数字电路中的阻抗匹配、传输线长度及EMC问题的仿真,根据仿真结果分析给出了相应解决办法。文章还对高速电路设计中电源层分配、时钟设计进行了讨论。     

非线性负载简化模型及其应用

为实现复杂网络电磁脉冲（electromagnetic pulse，EMP）耦合分析，针对非线性负载引起的分析效率和收敛性问题，提出了非线性负载精简建模方法，即将多项式表示的非线性关系用压控元件代替，指定器件动作时间表示开关响应时间，忽略温度等不必要参数，减少模型元器件个数等.采用该方法建立了气体放电管（gas discharge tube，GDT）和金属氧化物变阻器（metal oxide varistors，MOV）的精简SPICE（simulation program with integrated circuit emphasis）模型，并且用3种不同类型的脉冲激励端接非线性负载的传输线，进行了收敛性和仿真效率分析.结果表明，GDT和MOV的简化模型能够很好收敛，MOV的模型分析效率提高约30%，GDT的模型分析效率稍有劣化，但完全避免了理想开关元器件的使用，与实际器件的工作原理一致.这些建模方法具有较强的普适性，可以移植到其他非线性负载的建模上，例如与线缆耦合的精简计算模型相结合，从而提高超大系统的电磁兼容（electromagnetic compatibility，EMC）设计与评估效率.     

多工器的综合与设计

介绍了一种通过特征多项式综合多工器耦合系数的方法。该方法在低通原型频域中运用迭代算法计算优化多工器整体及各支路滤波器的特征多项式,综合得出的各支路耦合系数考虑进了多工器其余支路的影响,大幅缩短滤波器优化时间,且各支路滤波器的传输零点位置可根据需要指定。该方法也适用于双工器及三工器的推导。最终利用软件Ansoft Designer,综合设计并检验一个四工器,利用该方法得出的曲线与预期吻合。     

双绞传输线电磁兼容特性的FDTD分析

将曲线坐标系中的时域有限差分法（FDTD）拓展到空间为任意媒质情形，然后针对双绞传输线的特殊结构综合运用曲线坐标系、圆柱坐标系、旋转坐标系和子域连接法进行空间网格划分、FDTD建模，并通过求解双绞传输线和平行传输线的特性阻抗对该建模的准确度进行了验证，最后在空间线源激励下对双绞线和平行线的电磁兼容特性进行了比较，可以看出双绞线对空间电磁场的耦合能力远远低于平行线。     

Complete Monte Carlo RF analysis of “real”short-channel compound FET's

A comprehensive RF analysis technique based on ensemble Monte Carlo (EMC) simulation of compound FET's with realistic device geometry is presented. Y-parameters are obtained through Fourier transformation of the EMC transients in response to small changes in the terminal voltages. The terminal currents are statistically enhanced and filtered to allow for reliable y-parameters extraction. Improved analytic procedure for extracting the intrinsic device small-signal circuit components is described. As a result, stable y-parameters and reliable circuit components can he extracted for the whole range of device operation voltages. Parasitic components like contact and gate resistances are included in the y-parameters at a post processing stage to facilitate the forecast of the performance figures of merit of real devices. The developed RF technique has been applied in the EMC simulation of pseudomorphic HEMT's (pHEMT's) fabricated at the Glasgow Nanoelectronics Research Center. Good agreement has been achieved between the simulated and measured small-signal circuit components and performance figures of merit     

Field coupling to nonuniform and uniform transmission lines

We study time-domain and frequency-domain responses of nonuniform and uniform transmission lines excited by incident electromagnetic waves. Externally excited uniform transmission lines permit closed-form solutions in terms of inverse chain matrix, whereas nonuniform lines cannot be analytically solved, in general. We adopt a method of equivalent cascaded network chain as the method of solving the latter situation. Useful and compact expressions for the load currents induced at terminal loads are derived. To confirm the validity of this method and the forcing terms, theoretical and experimental results of coupling calculations for a few typical (uniform/nonuniform) line geometries, relevant in the EMC field, are presented and discussed