Introduction to Electromagnetic Compatibility

https://espace.library.uq.edu.au/view/UQ:e38288a/UQe38288a_OA.pdf

High-performance SnSe thermoelectric materials: Progress and future challenge

Методы подавления шумов и помех в электронных системах. (Noise reduction techniques in electronic systems)

Introduction to the Finite-Difference Time-Domain (FDTD) Method for Electromagnetics provides a comprehensive tutorial of the most widely used method for solving Maxwell's equations -- the Finite Difference Time-Domain Method. This book is an essential guide for students, researchers, and professional engineers who want to gain a fundamental knowledge of the FDTD method. It can accompany an undergraduate or entry-level graduate course or be used for self-study. The book provides all the background required to either research or apply the FDTD method for the solution of Maxwell's equations to practical problems in engineering and science. Introduction to the Finite-Difference Time-Domain (FDTD) Method for Electromagnetics guides the reader through the foundational theory of the FDTD method starting with the one-dimensional transmission-line problem and then progressing to the solution of Maxwell's equations in three dimensions. It also provides step by step guides to modeling physical sources, lumped-circuit components, absorbing boundary conditions, perfectly matched layer absorbers, and sub-cell structures. Post processing methods such as network parameter extraction and far-field transformations are also detailed. Efficient implementations of the FDTD method in a high level language are also provided. Table of Contents: Introduction / 1D FDTD Modeling of the Transmission Line Equations / Yee Algorithm for Maxwell's Equations / Source Excitations / Absorbing Boundary Conditions / The Perfectly Matched Layer (PML) Absorbing Medium / Subcell Modeling / Post Processing

Introduction to the Finite-Difference Time-Domain (Fdtd) Method for Electromagnetics

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.

/pdf/investigation-of-fundamental-emi-source-mechanisms-driving-2v86hmhn28.pdf

Investigation of fundamental EMI source mechanisms driving common-mode radiation from printed circuit boards with attached cables

Circuit board mounted, shunt capacitive filters are less effective at high frequencies because of the mutual inductance (M) that exists between the input and output ports. An approximate expression for the mutual inductance is M=(/spl mu/h/2/spl pi/)ln(h/a); where h=via length and a=radius of the via connecting the capacitor to the return plane. The reduced mutual inductance associated with the new, three-terminal, surface-mounted capacitor results in more than 15 dB increased attenuation compared to two-terminal capacitors over the 0.3-6.0 GHz range with 50 /spl Omega/ source and load terminations.

/pdf/improving-the-high-frequency-attenuation-of-shunt-capacitor-1gsl1yshts.pdf

Improving the high-frequency attenuation of shunt capacitor, low-pass filters

Depot a partir de solutions aqueuses de couches pouvant etre d'amorphes a polycristalllines. Caracterisation electrique et optique

Electrodeposition and Analysis of Tin Selenide Films.

Parasitic inductance in printed circuit board geometries can worsen the EMI performance and signal integrity of high-speed digital designs. Partial-inductance theory is a powerful tool for analyzing inductance issues in signal integrity. However, partial inductances may not adequately model magnetic flux coupling to EMI antennas because the EMI antennas are typically open loops. Therefore, partial inductances may not always accurately predict radiated EMI from noise sources, unless used in a full-wave analysis such as PEEC. Partial inductances can be used, however, to estimate branch inductances, which can be used to predict EMI. This paper presents a method for decomposing loop or self inductances into branch inductances. Experimental as well as analytical investigations are used to compare branch- and partial-inductances.

/pdf/considerations-for-magnetic-field-coupling-resulting-in-1vws8t10uk.pdf

Considerations for magnetic-field coupling resulting in radiated EMI

The maximum coupling between printed circuit board components connected to the same power-ground plane pair often occurs at or near power bus resonances. Theoretically, the transfer coefficient, S/sub 21/, between two locations on the power bus can be as high as 0dB (i.e. perfect coupling) near resonant frequencies. However, in practice the coupling is usually much less due to losses in the power bus structure. Determining exactly what the maximum coupling will be in a lossy power bus structure requires a numerical model or measurement. However, an estimation of the maximum coupling can be obtained by drawing an analogy between two-dimensional printed circuit board power buses and one-dimensional transmission lines. In this paper, a one-dimensional lossy transmission-line model is employed to simulate power-ground plane pairs and calculate S/sub 21/ between a noise source and a load. A simple formula for estimating the maximum coupling is derived from the transmission line model. This formula illustrates the effect that plane spacing, dielectric loss and board dimensions have on the maximum coupling between components attached to the same power bus structure.

/pdf/estimation-of-printed-circuit-board-power-bus-noise-at-4koonsowy4.pdf

Estimation of printed circuit board power bus noise at resonance using a simple transmission line model

Specific design criteria are proposed to mitigate radiated emissions from a resonant enclosure excited by a heat sink acting as a microstrip patch antenna source. In this particular application, the EMI mechanism is assumed to be due to coupling from the dominant TM/sub 010//sup x/ mode to one or more resonant modes associated with the enclosure dimensions. The enclosure is then presumed to radiate, at the enclosure resonance frequencies, through one or more apertures, slots, or seams. The EMI-reduction strategy consists of shifting the resonant frequency of the dominant-patch antenna mode by dielectrically loading the patch antenna with thermal-gasket material having a specified electric permittivity. Specific formulas and graphs are presented showing how to select the electric permittivity of the thermal-gasket material in order to obtain a given frequency shift. A comparison of experimental measurements with the predictions of the design criteria indicates that frequency shifts of up to approximately three times the bandwidth of the patch resonance can be predicted with reasonable accuracy. In at least two different commercial products that we are aware of, changing the electrically insulating heat sink gasket materials has solved specific radiated EMI problems.

T.P. Van Doren

Papers

Improving the high-frequency attenuation of shunt capacitor, low-pass filters

Electrodeposition and Analysis of Tin Selenide Films.

Considerations for magnetic-field coupling resulting in radiated EMI

Estimation of printed circuit board power bus noise at resonance using a simple transmission line model

EMI considerations in selecting heat-sink-thermal-gasket materials