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.

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

The authors describe a computer code, called EMIcheck, that was developed to perform an EMC (electromagnetic compatibility) evaluation of printed circuit boards laid out using the Mentor Graphics Boardstation software. The algorithm analyzes aspects of component placement and trace routing while searching for violations of basic EMC design principles. The algorithm is implemented in a code designed to work with a widely used board layout and routing program. This code can help novice and experienced circuit board designers to avoid mistakes that may result in serious EMC problems. >

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An algorithm for automated printed circuit board layout and routing evaluation

The analysis of shielding enclosures is complicated by the existence of apertures and cables. The finite-difference time-domain (FDTD) method can model shielding enclosures with complex geometries, but has difficulty modeling wires and cables of arbitrary radii. Modeling the wire by setting the axial component of the electric field to zero in the FDTD results in a wire with a radius determined by the mesh discretisation. Neglecting wire radius in applications such as electromagnetic interference (EMI) or printed circuit board modeling may result in gross errors because near field quantities are typically sensitive to wire thickness. Taflove (1990) developed a wire modeling algorithm for FDTD analysis which models wires well for far-field calculations such as the radar cross section. The method uses a quasi-static field approximation to model wires with a user-specified radius. The wire model is reviewed and investigated for near-field accuracy via input impedance computations, since FCC class A and B regulations are tested in the near field. The input impedance for a center-fed dipole antenna is computed with FDTD methods and compared to the input impedance results from moment methods. A simulation of a shielding enclosure with an attached cable demonstrates the utility of FDTD analysis in EMC applications.

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FDTD modeling of thin wires for simulating common-mode radiation from structures with attached cables

Noise on the DC power-bus attributed to device switching is among the primary sources of EMI and signal integrity problems. A mixed-potential integral equation formulation with circuit extraction approach is used to model the planar multi-layer power-bus geometry, which can also include arbitrary shaped power regions on multiple layers. Incorporating vertical discontinuities, e.g. decoupling capacitor interconnects, is a critical aspect of the modeling, and must be done properly since they are included as a lumped element model and not as a part of the MPIE formulation. Agreement with experimental results verifies the validity of the present approach.

/pdf/incorporating-vertical-discontinuities-in-power-bus-modeling-sz24gc1sqw.pdf

Incorporating vertical discontinuities in power-bus modeling using a mixed-potential integral equation and circuit extraction formulation

An investigation has been undertaken to further study the fundamental mechanisms responsible for inducing high frequency common mode currents on wires attached to multilayer printed wire boards (PWBs). Previous work reported in the EMC literature has demonstrated that the presence of unintended common mode currents on the external cables of electronic equipment is often the primary source of radiated EMI at frequencies above 30 MHz. In an attempt to reduce the magnitude of these currents to yield "quieter" electronic products, many EMC engineers have implemented segmented or "gapped" ground plane geometries in multilayer PWB designs. The objective of this study is to explore and develop a better understanding of the underlying electrical properties of such geometries. The establishment of a theoretical basis and empirical validation for such methods could then be used to construct a set of fundamentally sound EMC design guidelines for PWBs operating at high frequencies with attached cables. >

/pdf/common-mode-currents-induced-on-wires-attached-to-multilayer-m6xbf1v9lu.pdf

Common mode currents induced on wires attached to multilayer printed wire boards with segmented ground planes

This paper describes a case study covering the evaluation and reduction of the radiated EMI from an 18" liquid crystal display (LCD) monitor. The evaluation was completed in two parts: first potential EMI sources at the printed circuit board (PCB) level were identified, then the EMI antennas driven by these sources were analyzed. Methods for reducing the EMI were described in detail, and where applicable, those modifications were applied. Radiated measurements demonstrate the effectiveness of these recommendations.

T.P. Van Doren

Papers

An algorithm for automated printed circuit board layout and routing evaluation

FDTD modeling of thin wires for simulating common-mode radiation from structures with attached cables

Incorporating vertical discontinuities in power-bus modeling using a mixed-potential integral equation and circuit extraction formulation

Common mode currents induced on wires attached to multilayer printed wire boards with segmented ground planes

EMC analysis of an 18" LCD monitor