The Electromagnetic Compatibility Society (EMC-27) provides a networking environment for engineers involved in EMC test and/or design efforts. The EMC Society also provides a forum for sharing ideas and industry information.
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Application Notes & Articles
Components & Material
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LI Test Labs
LI EMI/EMC Reps
Not All Capacitors Are Created Equal
Jon A. Rhan - Kemet
The various dielectrics available and their pros and cons are discussed in addition to EMI suppression using capacitors, filter networks and other technologies. Related topics also explored include capacitor reliability and performance differences between capacitor types. While there are many considerations in choosing the proper capacitor for EMI applications, an online WEBSPICE tool can help determine what capacitors to use in an EMI/EMC network.
Indirect Lightning Testing to DO 160 & MIL-STD-461G
Lou Feudi - Ametek Compliance Test Solutions
MIL STD 461G was published this year for comment and is expected to achieve final publication by year end, 2015. DO-160 G Section 22 has been incorporated, in part, into MIL STD 461G, newly created section CS117. The presentation reviews all added requirements to CS117, and a brief history of the DO-160 Section 22 requirements.
Solving EMI With Ferrites
Paul Zdanowicz - Fair-Rite
The presentation discusses specifying and choosing ferrite components for EMI suppression. Topics include the basic operation of ferrite material and a review of ferrite applications with an in depth discussion of EMI Suppression. Also covered are intrinsic material characteristics, factors affecting core selection, choosing a material based upon frequency of operation, and environmental & bias conditions - all with the goal of narrowing the options when choosing a ferrite solution.
Filters, Connectors and Shielding
Rick Taylor and Jason Pedruzzi - Filconn
Filter connectors are generally perceived to be one of life’s necessary evils, and while they are expensive, there are ways to get extra value from the filter connector as it is designed into the system. Also discussed will be the pros and cons of transient suppression using diodes or MOVs.
PCB and System Shielding
Jeff Davis and Timothy Liu - TennMax
The presentation contains information useful for current users of metal cans or multi cavity metal housings on PCBs. Technologies discussed include; Robotically dispensed conductive gasket (Form in Place), Metallizing plastic via Physical Vapor Deposition and Conductive polymers. For optimal size, form-factor and weight, combination design approaches using metal/metalized plastic/FIP and conductive polymers are also covered.
EMI/EMC Filters: A Technical Presentation
David Stanis - WEMS Electronics
The talk addresses the various types of industry-wide custom EMI filters both single-circuit components and multi-circuit filter assemblies. Discussion includes common-mode and differential-mode interference and filtering techniques, MIL-PRF-28861 “S” Level requirements and problems. A review of EMI Filter Source Control and Specification Control Drawings is also provided.
Ferrite Components for EMI Suppression
Paul Zdanowicz - Fair-Rite
The presentation contains information useful to specify and choose ferrite components for EMI suppression. Topics covered are the basic operation of ferrite material with an in-depth discussion of EMI Suppression. The discussion includes Intrinsic Material Characteristics, factors affecting core selection, how to choose a material based upon frequency of operation, and environmental and bias conditions.
Advanced EMC Applications
Marcin Szajner - Würth Elektronik
The presentation covers advanced EMC topics including magnetics, attenuation, coupling modes, emissions and transformers.
Characterizing Products Against Wireless Communication Threats
Tom Mullineaux - Milmega
4th Generation (4G) cell phones are now available on the open market providing the high data-rate exchanges required for video streaming. Faster data rates while maintaining a modest channel bandwidth inevitably means more complex digital modulation techniques. Product standards may stipulate test bands that cover the frequency bands of the threats, however the analog modulated test signal is comparatively benign and does not ensure product RF immunity to these omnipresent signals. The talk includes classification of current threats; prevalence and nature of 2G, 2.5G, 3G and 4G signals; the time/event when the threat greatest; complex waveform peak to average ratios; amplifier power back-off required for test signal integrity; near-field/far-field interference, and simulating the threats in an ALSE or GTEM Cell.
Use of TVS Diodes in Connectors
Bruce R. Lane - Jerrik
The presentation discusses approaches to incorporation of TVS diodes in connectors, with a focus on TVS in lightning protection.
Jason Koshy- Transtector/PolyPhaser
This presentation is geared toward understanding EMP (Electromagnetic Pulse) threats and how to mitigate these events. HEMP (High altitude EMP), SREMP (Surface generated EMP), Solar Flairs, EMP, EMI (Electromagnetic Interference) and transient (lightning and manmade surges) are covered. This presentation discusses how these events are generated, related industry standards, and how to protect a critical system from these events.
ASC C63 Overview
Don Heirman - ASC
Commercial EMC standards have been around for decades. They are produced by many committees such as those in the International Electrotechnical Commission (IEC), the European Telecommunications Standards Institute (ETSI), the IEEE EMC Society, and more close to home the American National Standards Institute (ANSI) accredited standards committee. The US Federal Communications Commission references in their Rules several ANSI ASC C63® standards such as the omnipresent ANSI C63.4 on product emission testing, C63.19 on Hearing ad EMC compatibility, and C63.17 on unlicensed Personal Communications Services (UPCS). Hence while such standards are voluntary, when they are specified by the FCC (or even a user), they become mandatory. This talk reviews the standards activity of C63® showing what are the “hot” topics and the extent of the work and when they might be published. Among those highlighted will be the work on test site validation, transmitter compliance testing, and others.
EMI Basic Principles, Understanding Inductors & Transformers
Douglas A. Toth - Wurth Electronics
The types of Electromagnetic interference over various frequency ranges and their classification are covered, including conducted differential mode interference, common mode interference and radiated interference. Recommendations and examples for lowering these types of interference are presented. Basic information about materials such as loss characteristics, frequency of operation and inductive properties are also part of the presentation.
Updates in International Standards: Harmonics and Flicker
Robert Emerson - Zes Zimmer
This presentation looks at the changing landscape of international standards governing harmonic currents and voltage fluctuations (flicker) on the low voltage alternating current public mains networks, and the ensuing impact on product design and test for low and medium power applications. Highlighted is the impact resulting from changes to international standards for harmonic limits EN/IEC 61000-3-2 and EN/IEC 61000-3-12 and flicker limits EN/IEC 61000-3-3.
Steps in Designing Shielded Enclosures
Praveen Pothapragada - Equipto Electronics Corporation
This presentation discusses the current vulnerability of our data centers and electronics packaging methods. Included are tradeoffs considered for mechanical flange designs, RF absorptive materials, RoHS, and material selection. In addition, the EMC test results and test plan are also presented. Finally, the implications of these approaches with other types of electronics enclosures under varying environmental requirements (seismic, military level shock/vibe) are presented.
EMI Compliance Solutions and Inductive Materials
Douglas A. Toth - Wurth Electronics Midcom
An Introduction to the EMI applications of PCB Layout, Common & Differential Mode Filtering and the use of Shielded and Unshielded Inductors. In addition, the selection of various core materials for transformers and inductors are discussed.
EMC and the Rail & Transit Industry
Walter A. Poggi - Retlif Testing Laboratories
The presentation focuses on the growing awareness for the need of Electromagnetic Compatibility in today’s evolving rail and transit industry. The transition from an electromechanical “world” to a microprocessor one will be reviewed as well as look at the growing technologies of Positive Train Control and Communications-Based Train Control. Reviewed in the presentation are the building blocks of current EMC compliance programs used by agencies such as the New York City Transit as well as an overview of the normal EMC testing requirements imposed on today’s rail and transit equipment.
Updates on the new release of IEC 61000-4-3:2006 Edition 3
Jason H. Smith - AR Worldwide
A discussion of the changes that have been made to the IEC 61000-4-3 Edition 3 standard which include: Higher frequency range, more clearly defined field and setup requirements. A discussion of the present work being done in Working Group 10 on IEC 61000-4-6 and IEC 61000-4-3, and review the basic process and timing of revisions and standards development within the IEC.
EMC Pulse Parameter & Custom Thresholding
Mike Hertz - LeCroy Corporation
Techniques for measuring electrostatic discharge, electromagnetic coupling, and fast transient pulses are described, using custom measurements and thresholds. Measurement filters, segmented acquisitions, enhanced pulse parameter definitions, and other techniques are applied. A measurement integrity comparison using standard measurement techniques vs. EMC-specific measurement techniques is shown.
Multi-Antenna Versus Single-Antenna RF Immunity Testing
Thomas Mullineaux - MILMEGA
The technical and practical aspects of testing over 1-10GHz with either multiple high-gain horn antennas, or with a single medium-gain horn antenna are reviewed. The compound frequency effect of cable-loss/antenna-gain is introduced as is the effect of antenna gain on test illumination area.
Fundamentals of the Plane Electromagnetic Shield
Richard J. Mohr - R J Mohr Associates
In the discipline of electromagnetic compatibility (EMC), electromagnetic shields can be considered as the top level of control of electromagnetic interference (EMI). This lecture reviews the basics of the plane electromagnetic shield as approached by Schelkunoff. He treated shielding analysis by analogy to transmission line analysis. He modeled the shield as a section of lossy transmission line, and then reduced the associated transmission line equations to characterize the shield in terms of factors for its reflection loss and absorption loss, and an additional factor to correct for multiple reflections within the shield. His model has served as the starting point for nearly all subsequent work in shielding analysis. He first derived his model from conventional transmission line equations; then he derived the same model by considerations of multiple reflections. The latter approach provides solid insight into the shielding parameters, and particularly to the important correction factor.
Metallization of Plastics
Jim Skelly - Cybershield
The presentation reviews plastic resins that can be coated, processes used to metallize plastics, and metals that can be applied onto plastics. There is an examination of mechanical design guidelines for metallized plastic parts for the various coating processes. Coating performance, including resistivity and shielding effectiveness is discussed, as is conductive coating quality metrics (adhesion, metal coating thickness, and resistivity) and how they are measured to ensure compliance with customer specifications. There is also an analysis of the process, design guidelines, plastic resins and application of precision 3D circuits onto plastics. A number of commercial applications using metallized plastics are reviewed. Finally, metallized plastics and the impact of RoHS (Reduction of Hazardous Substances) and WEEE (Waste from Electrical and Electronic Equipment) is assessed.
Mohr on Minimizing Crosstalk in Wiring and Cabling
Richard Mohr – RJ
This lecture covers the “why and how” practices to minimize crosstalk in wiring and cabling. Optimum shielding and grounding practices are outlined. Common pitfalls are highlighted, and corrective measures shown. Concise models remove the mystery and “black magic” in wiring and cabling, and allow for accurate prediction of crosstalk.
Performance Characteristics of Capacitors
Peter A. Blais - Kemet
The technical advancements made with Ceramic MLCC, Tantalum-MnO2, Tantalum-Polymer and Aluminum-Polymer capacitor technologies are discussed. In addition, these devices are compared in terms of frequency response, de-rating and lead-free process capability.
Understanding Overcurrent Circuit Protectors
Carl Lindquist - San-O Industrial
Those responsible for designing circuits using overcurrent protectors, as well as those purchasing such protectors, often misinterpret specified parameters and “equivalent” devices when seeking primary and secondary sources. This presentation provides a brief overview of various types of overcurrent protectors, including fuses, PTCs, circuit breakers, etc. The discussion concentrates on fuse design, the relative strengths and weaknesses of different types of fuse designs, important protector parameters and documentation recommendations.
Solving the Galvanic Corrosion issue in EMI Shielding
Harry Fuerhaupter - Potter Industries
Galvanic corrosion can be a significant concern for product designers in EMI shielding applications. The mechanism behind galvanic corrosion and the selection of shielding materials that will minimize this effect, are discussed. Also, a new conductive filler for elastomer EMI gaskets is presented. The new filler exhibits very low galvanic corrosion while providing excellent shielding.
Broadband Over Power Lines
Ed Hare - American Radio Relay League
The basic concepts of Broadband Over Power Lines (BPL) are reviewed, along with its potential impact on HF communications. ARRL efforts to protect the interests of amateur radio are also discussed. The lecture summarizes studies, including field trips to BPL trial areas, and testing performed by ARRL, and the League's work in the standards arena.
Electromagnetic Scanning - Root Cause Diagnostics
Doug McKinnon - Emscan Corporation
Electromagnetic scanning improves designer productivity, while reducing costs and time-to-market. This lecture describes how electromagnetic scanning plays a vital role in pre-compliance testing and in sustaining operations. Near-field and far-field relationships are discussed, along with the value of combining electromagnetic scanning, cable measurements and chamber results. Applications such as immunity (susceptibility) testing, evaluation of filters and shields, and finding the sources of radiation will be addressed.
New Developments in Shielding Materials
Gary Fenical - Laird Technologies
Advances in electronic equipment are occurring at a rapid pace. The wireless revolution, increasing power levels in computers and servers, higher frequency systems, decreasing size of cell phones, to name a few. To keep pace with the EMI shielding needs of these devices, a wide range of new and improved products have been developed over the past few years and many more are on the drawing boards. Just about every class of shielding product has seen noteworthy changes. The uses, properties, and advantages of these new materials and advanced EMI shielding product designs are described.
The Ten Commandments of Electromagnetic Compatibility
Dave Arthurs - Spectrum Control
The lecture covers the types of EMI filters, propagation modes and methods of suppression. Basic circuits of Low Pass filters are explored as well as their impact on timing and I/O impedance selection criteria. In addition, applicable EMC specifications are also presented. The lecture is intended for individuals involved with EMC design and/or EMC testing/troubleshooting.
Ferrite Cores for EMI Suppression
Paul Zdanowicz - Fair-Rite Products
The presentation discusses the specification and selection of ferrite components for EMI suppression. Topics covered include the basic operation of ferrite material, their operation in reducing EMI and the significance of test methods.
The Legal Aspects of Regulatory Compliance
Terry Mahn - Fish and Richardson
Legal issues involving domestic and international product standards development, harmonization, and compliance in the areas of EMC, electrical safety, RF emissions, telephony, and RF safety. FCC issues including all facets of spectrum allocation, wireless technology authorization, and licensing equipment approvals.
Test Receiver vs. Spectrum Analyzer
Certification, Accreditation & Endorsement
This is a broad topic and covers various aspects of the Accreditation, Certification, and Endorsement processes that EMC and TEMPEST Engineers must contend with. This presentation is carried out by three members of the Long Island IEEE EMC Chapter who, along with their businesses, collectively possess the laboratory and personnel credentials to be discussed, and programs and processes needed to obtain them.
Evolution of EMI
Filters: Discrete to Integrated Devices
EMI attenuation options have progressed well beyond discrete solutions. This talk centers upon the integration of filters within passive components. The impact of these fixes upon system design is discussed, and next generation passive components are outlined. Areas of discussion will include: the integration of LC-T configuration filters into a ceramic chip (0805 and 1206 sizes); the integration of LC-T filters with MOVs to form active LC-T filters in 0805 and 1206 array packages; reduction/control of parasitic parameters (ESL/ESR) within capacitors - impact upon signal integrity; and, the next generation Ball Grid Array Passive Components.
> Viewgraphs will not be posted
RF Safety Analysis
There is no question that there is an overlap of technologies and skills between EMC testing and RF safety analysis. In some cases, even the same measurement equipment is used. But while EMC testing involves testing in accordance with very specific guidelines, RF safety analysis is far less disciplined. There are many reasons for this, including a lack of consensus of what constitutes "safe" or compliant versus "unsafe" or noncompliant. It all starts with understanding of how the biology has driven the standards and regulations. It also involves the work environment and both administrative and engineering controls that can be used to reduce the possibility of somebody being hurt. Topics will include: sources of potentially unsafe levels of RF energy; basic biology and an overview of standards and regulations; measurement equipment; and the elements of a good RF safety survey.
Virtually every electronic device or system designed today needs to comply with EMI/EMC standards. Proper EMI/EMC design, throughout the development cycle, is necessary to cost-effectively ensure that products operate reliably in their intended electromagnetic environment without being susceptible to electrical noise from other devices, or generate excessive noise that can interfere with other devices. Meeting this goal has become especially challenging in recent years, due to the ever-growing use of electronics, increasing clock frequencies and escalading wireless-bandwidth demands.
The presentation will review basic EMI/EMC definitions, and summarize some of the applicable standards (EU, MIL, FCC, RTCA, etc.). Following will be a discussion on radiated emission/susceptibility control and conducted emission/susceptibility control, and their impact on electrical/mechanical design. Topics covered will include signal spectra, enclosure/cabling design, PWB design, and signal/power distribution. EMI/EMC design process will also be discussed.
of Aircraft and Avionics
All of us have witnessed, and many have been awed by, the pure power of Mother Nature's fury during thunderstorms. While we may marvel at lightning from a distance, too close of a call can be frightening and downright dangerous. The aircraft industry also must respect lightning strikes. With electrical currents of upwards of 200,000 amperes generated during severe cloud-to-ground strikes, aircraft, which intercept or trigger the lightning channel, must be able to fly through it with minimal structural damage and minimal loss/upset of on-board avionics, flight controls, and electrical systems. Discussion will center on the lightning environment, the effects of lightning on structure and coupling mechanisms for equipment, commercial and military design/test requirements, protection design scenarios and techniques, and certification/qualification plans, test methods, and procedures.
Connectors, Then and Now
EMI, EMP, ESD, lightning, and similar design/test requirements are typically imposed on most military and commercial electronic equipment built today. EMI filter connectors are a viable option when equipments must operate in such adverse environments. Improvements in technology have allowed EMI filter connectors to migrate from a design fix that was implemented as an "afterthought" to a design solution, that is planned for at the beginning of the equipment design process. Improvements have not been limited to filter technology. Available design tools allow the user of filter connectors to more easily select the correct part and ensure that these parts will survive required surge, lightning, and ESD levels. The use of present-day filter connectors for common and differential mode suppression in RF and transient environments, will be presented. In addition, technical descriptions of pSpice models, surge analysis tools and details of currently available product lines will also be presented.
Requirements and Methodology
After much debate and long delay, the EU required that harmonic and flicker testing be included in the suite of EMC requirements for all CE marked electronic products sold on, or after, January 1, 2001. Testing for harmonic content is specified in IEC61000-3-2, and testing for flicker is specified in IEC61000-3-3. Amendment A14 of IEC61000-3-2 was issued to simplify the harmonics testing, but it added some new requirements in the process. The end result has been an increase in testing criteria needed for CE marking. Amendment A14 also added "interharmonic grouping tests," and these will be required beginning in August of 2005. This expansion means that the manufacturer, and EMC Engineer have to be aware of the effects that harmonics from other sources have on products being developed and sold.
The New EN60601-1-2
The new EN60601-1-2, 2001 Standard contains the new set of EMC requirements for medical equipment to be sold in the EU and is also recognized by the FDA. This standard covers not only the requirements but also documentation that needs to accompany products to market. We will discuss the differences to the existing standards and show how the newer document has aligned itself to other international requirements.
RF & EMC Considerations in Printed Wiring Board Design
Recent advances in digital and analog technologies have presented new challenges to the design of Printed Wiring Boards (PWBs). As clock frequencies approach the L-Band region, digital designers are now faced with considerations that were once only viewed as analog/RF concerns. These considerations include dielectric loss, skin effects and impedance matching. High dynamic range analog components also present unique challenges concerning noise immunity and stability. The presentation covers PWB material selection, signal integrity, power distribution and grounding, and is intended for analog/RF, EMC and digital engineers.
View of Electromagnetic Life above 100 MHz
Interest in electromagnetic life above 100 MHz has increased in the past decade, primarily due to an increase in high speed digital electronics and telecommunications. In this frequency regime, many of the usual simplifying assumptions are no longer true and the EMC engineer must adopt a new way of looking at the problems.
An intuitive approach allows the engineer to visualize the system as a collection of components whose characteristics can be estimated, or if necessary, measured. Effects, such as parasitic effects, absorption, radiation losses and wavelength effects become more significant above 100 MHz, but are reasonably well understood.