微带传输线间的小孔耦合分析

本文利用保角变换求势函数的方法，导出了微带线中的归一电场分布的表示式，并根据小孔耦合理论导出了微带线间通过公共壁上圆孔耦合度的表示式。它表明耦合度是频率、小孔半径及电磁极化率的函数。     

基于电磁耦合的无线能量传输技术应用及展望

电磁耦合能量传输作为一种摆脱传统导线连接的能量传递方式,具有灵活、便捷、安全系数高等优点。在工农业生产和生活的各个领域都具用巨大的应用价值和潜力。针对电磁耦合能量传输技术优点和应用潜力,了解电磁耦合的能量传输技术研究现状,推进该技术的进一步走向实践和应用显得尤为重要。通过分析最新文献和研究成果,归纳总结出研究现状和发展趋势;研究结果表明:电磁耦合的能量传输技术的研究重点主要是如何提高传输功率、传输效率及传输距离等;该研究工作能够为电磁耦合的无线能量传输技术研究提供支撑。     

超宽带双极性脉冲对机箱孔缝的耦合特性研究

为了解超宽带双极性电磁脉冲对于机箱孔缝的干扰与损伤规律,使用基于时域有限积分法的CST电磁仿真软件对机箱建模进行仿真,并分析了脉冲特性及孔缝结构等因素对于脉冲耦合效应的影响.研究表明:双极性脉冲在通过小孔缝耦合进入腔体内部时,脉冲能量主要在孔缝附近,进入腔体后迅速发生衰减,腔体内部的耦合场由腔体谐振模式主导.双极性脉冲...     

窄缝耦合共振特性分析

应用时域有限差分法模拟了正弦波和电磁脉冲对窄缝的耦合过程，计算了直缝和扭曲缝的耦合穿透功率和能量，通过分析窄缝的耦合传输系数变化曲线，得出窄缝发生耦合共振的条件和规律。并通过直缝与扭曲缝耦合情况的比较，表明了扭曲缝具有较好的电磁防护能力。     

短波通信电台带内辐照试验替代方法*

通过分析典型短波电台带内辐照试验,提出改变辐照试验电磁能量耦合途径以简化试验装置的设想.通过理论分析和仿真计算,分析了短波电台带内辐照试验的电磁能量耦合途径,得出电台天线是短波电台带内辐照试验主要能量耦合途径的结论,通过设计电磁辐照法和电流注入法比较试验,验证了仿真计算结论,且证明在该试验条件下电流注入法可以替代电磁辐照法.该结论可以推广到电磁能量耦合途径单一的电磁辐照试验中.     

瞬态电磁波对电子设备电缆的电磁耦合分析

瞬态电磁波对电子设备电缆的电磁耦合预测分析,是电子设备的电磁兼容性预测与分析的重要方面。提出了电磁场对电缆的电磁耦合模型,介绍了电磁耦合的数学计算公式,并对3种瞬态电磁脉冲对电缆的电磁耦合进行了预测分析,数值分析结果对有效抑制和减小电磁波对电缆的电磁干扰有一定的参考价值和指导意义。     

简易无线能量传送系统

本文设计了一种简单实用的无线传能系统,直流电经振荡电路转化成交流电,利用电磁感应原理,通过线圈电磁耦合,能量以无线的方式传送至负载设备。     

微带传输线间的小孔耦合分析

本文利用保角变换求势函数的方法,导出了微带线中的归一化电场分布的表示式,并根据小孔耦合理论导出了微带线间通过公共壁上圆孔耦合的耦合度表示式。它表明耦合度是频率、小孔半径以及电磁极化率的函数。     

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。     

直升机中电磁耦合薄弱路径的确定方法

直升机结构复杂、空间狭小、设备繁多,从而导致全机电磁环境异常复杂。为了快速定位全机电磁干扰耦合的通道,该文提出一种电磁干扰耦合薄弱路径的确定方法。它通过将复杂电磁干扰耦合网络转换成电磁干扰耦合有向图,以电磁能量衰减量最小为基础,在指定频点处使用Dijkstra算法寻找出干扰源和敏感点之间的最短路径,从而确定电子系统的薄弱环节。使用该方法对直升机某处理机和电台系统进行了仿真分析,并成功地寻找出敏感设备受扰的主要耦合通道。仿真和分析表明该方法可有效地寻找出系统电磁耦合的薄弱环节,并为系统的电磁兼容问题提供支撑。     

通过导电壁上窗口透入的电磁波对人体作用的研究

本文用时域有限差分法和人体非均匀电磁模型研究了通过无限大导电壁上窗口透入的电磁场与人体的相互作用。首先对平面电磁波通过导电壁上窗口的透入特性进行了计算,并与解析解进行比较,证明了计算的可靠性。在此基础上对不同极化情况的入射平面波的透入场与靠近窗口的坐姿人体模型的作用进行了研究。计算了人体模型中的电磁场分布和所吸收的电磁能量。     

Electromagnetic radiation and scattering at the American Universityof Beirut

This paper presents the work carried out at the American University of Beirut on electromagnetic radiation and scattering, using the characteristic-modes theory. Several problems of various two-dimensional and three-dimensional geometrics have been considered: slots in a plane, slots in a conducting cylinder, a parallel plate-fed slot antenna, an aperture-fed waveguide, a rectangular aperture in a perfectly conducting plane, a cavity-backed aperture. The characteristic modes for each geometry were first computed, and the convergence of the solution was tested for all these problems. A combined characteristic-modes formulation, for the problem of electromagnetic coupling to conducting objects behind arbitrary apertures in a conducting plane, has been developed and used to solve many of these problems     

Frequency-domain upper bounds for signals on a multiconductor transmission line behind an aperture

This paper develops a technique for bounding the maximum voltages and currents at terminations of a muiticonductor transmission line (MTL) located behind an aperture-perforated conducting screen excited by an electromagnetic field in the frequency domain. The electromagnetic field is coupled through a small aperture as the excitation of a multiconductor transmission line behind the aperture. A model is presented in terms of external and internal sources which in turn create traveling waves on the multiconductor transmission line. These traveling waves transfer energy to the terminations. The energy at a termination is translated into voltages and currents from which the upper bounds are determined. These upper bounds are obtained using vector norms and associated matrix norms. The formulation is presented in the frequency domain to obtain useful upper bounds for analysis of multiconductor transmission line geometries with aperture excitation.     

Electromagnetic Pulse Penetration Through Small Apertures

The electromagnetic field penetration through small apertures is discussed for general aperture shapes. Approximnate analytical expressions are obtained for the penetration fields. In particular the fields that penetrate a small aperture into the region between two parallel, perfectly conducting plates are determined and some numerical results are obtained.     

EMI from airflow aperture arrays in shieldingenclosures-experiments, FDTD, and MoM modeling

Aperture arrays designed to provide airflow through shielding enclosures can provide part of the coupling path from interior sources to external electromagnetic interference (EMI). In this work, radiation through aperture arrays is investigated numerically and experimentally. FDTD modeling is compared with measurements on aperture arrays in a test enclosure. The method of moments (MoM) is also utilized to study radiation from apertures and to investigate the mutual coupling between apertures in an infinite conducting plane. A simple design equation for the relation between aperture size and number and shielding effectiveness is proposed     

Sur l’utilisation des équations intégrales en régime transitoire dans les problèmes d’électromagnétisme

It is possible in many cases by using space-time integral equations to compute the scattering and penetration of electromagnetic fields via explicit time-stepping diagrams. The case of conducting surfaces, thin scatterers, apertures and shieldings of finite conductivity are discussed with emphasis on the simplicity and the validity domain of the relevant equations. Examples concern the field of a far-located dipole incident on a cylinder with infinite conductivity, with an aperture or with resistive walls.     

Time-domain upper bounds for signals on a multiconductor transmission line behind an aperture

A technique for bounding the maximum voltages at terminations of a multiconductor transmission line (MTL) located behind an aperture-perforated conducting screen excited by an electromagnetic field in the time domain is developed. The electromagnetic field is coupled through a small aperture as the excitation of a multiconduetor transmission line behind the aperture. A model is presented in terms of traveling waves and multiple refleetion phenomenon. These traveling waves transfer energy to the terminations. The energy at a terminatian is translated into voltages from which the upper bounds are determined. The upper bounds are obtained using vector norms and associated matrix norms.     

On the Electromagnetic Field Penetration Through Apertures

A numerical method is presented for determining the electromagnetic field diffracted by an aperture in an infinite conducting plate. Comparisons are made with the results of approximations valid at low frequencies and high frequencies. Calculations of the electromagnetic field components in the aperture, in the near zone of the aperture, and in the far zone of the aperture are made and are compared with available measured data     

Electromagnetic coupling to a conducting wire behind an aperture of arbitrary size and shape

The electromagnetic coupling to a conducting wire behind an aperture in a plane conducting screen is analyzed. The aperture can be of arbitrary size and shape. The wire can be of finite length, with or without terminating loads, or of infinite length. The electric current on the wire and the equivalent magnetic current over the aperture region are calculated by the method of moments. An equivalent circuit for the effect of the aperture on the transmission line mode of the wire is derived.     

Resonant electromagnetic field coupled into a lossy cavity through a slot aperture

A new approach is proposed for determining the electromagnetic fields coupled from an incident plane wave into a lossy conducting cavity through a slot aperture under resonant conditions. Use is made of the duality between a slot and a conducting strip and of the equivalence between a strip and a wire. Simplified formulas are derived that are explicit and flexible. Determination of resonant fields inside a cavity is reduced to simple calculations. Numerical examples are given.