1998 Meetings

The linked titles of some meetings are the presentations speakers provided.

December 8, 1998: "A New Common-Mode Voltage Probe for Predicting EMI from Unshielded Differential-Pair Cables" by Neven Pischl, Bay Networks

Abstract: Common-mode (CM) currents on I/O cables are primary sources of EMI in many electronic devices. Measuring the CM voltage at the I/O connectors can be an alternative to measuring CM currents. Sources of CM currents and voltages are discussed, and a CM voltage probe for prediction of the EMI levels from unshielded differential twisted-pair cables is described. CM voltages at the RJ-45 ports were measured and correlated to the 10m E-field levels of 8 DUTs. A CM-voltage level that corresponds to the EN 55022 A limit has been derived. This allows the prediction of radiated emissions based on CM voltage measurements at the connectors. This bench-tool can be instrumental in reducing the time and cost of troubleshooting EMI problems.

Bio: Mr. Pischl started his career as a research assistant at the University of Zagreb in Croatia designing EM field sensors and studying protection against HF EM field exposure. After receiving his Masters of Science Degree from the University of Zagreb, he worked in the EMC department of Italian Aerospace "Aeritalia" in Turin designing EM Field probes and EMC testing space satellites and aircrafts. He was a guest scientist at the Austrian Research Center Seibersdorf researching the accuracy of EM-field measurements in near- zone of the ISM (industrial, scientific and medical) sources, and of broadband isotropic field probe calibration methods. At Philips Electronic Industry in Vienna, Austria, he held the position of Senior EMC Engineer and EMC Group Manager while working on EMC design for telefax and cordless telephone devices. While in Austria, he was on the Austrian National Committee for EMC in ITE devices.

Currently, Mr. Pischl works at Bay Networks in Santa Clara, CA. He is involved in EMC Design in 10/100 MBit, GBit, and wireless Ethernet devices. He is also involved in research for new measurement methods and publishing EMC layout Guidelines. He is a NARTE certified EMC engineer and a member of the IEEE EMC Society.

November 10, 1998: "EMC in the European Union" by Diethard Moehr, Siemens AG

Abstract: One of largest economic communities is the world is the European Union (EU). Manufacturers of products that are destined for this market must comply with stringent technical and marketing EMC regulations. Mr. Moehr will cover a number of important topics related to these requirements, and what measures US manufacturers can take now and in the future to simplify the EU EMC compliance process. Topics that Mr. Moehr will cover include:

  • European EMC Directive and national EMC laws
  • Legal requirements on EMC emission and immunity testing in the EEA (EU + Norway + Iceland + Lichtenstein)
  • EMC Directive and CE marking
  • Main EMC standards to be used
  • Application of the EMC Directive to modules, apparatus, systems and installations
  • Guidelines on the application of the EMC Directive
  • Market sampling testing in the EU
  • Penalties for violating the EU legislation on EMC
  • What is the SLIM initiative on EMC - Where does the EU move EMC wise?

Bio: Diethard Moehr is the Head of Staff Office, EMC, At Siemens AG, Erlangern Germany. He has been an active member of the EU EMC community for many years and is currently an active member in the following European Standards organizations: DKE (German Commission of Electrotechnique); ECMA (European Computers Manufacturers Association) including technical Committee TC20 on EMC; VDMA (Association of German manufacturers of Machines and Installations); ZVEI (Central Organization of Electrotechnical Manufacturers of Germany); IEC TC65 SCA WG4 (responsible for the IEC 801-X series); IEC TC77 SCA WG6 and IEC TC77 SCB WG3 (responsible for the IEC 61000-X-X series EMC Emission and Immunity standards); German Speaker for IEC TC77; German Deputy Speaker for IEC TC77 SCB; advisor of the European Commission on EMC, Directorate Generale, DG III, DG XII und DG XIII; and, starting in January 1999, Secretary of IEC TC77.

October 13, 1998: "Radiated and Injected Tests - When are they equivalent?" by Dr. Jose Perini, IEEE EMC Society Distinguished Lecturer

Abstract: The performance of radiated tests requires the use of very expensive facilities and equipment in order to produce the necessary high fields, while protecting the environment from interference. Several researchers looked at the possibility of reproducing these tests by strategically injecting some voltage and /or current sources in the equipment under test (EUT). This approach requires much lower signal levels reducing substantially the test cost. However no proof has ever been set forth showing if or when both tests are equivalent.

In this presentation the theoretical foundation for the equivalence of these tests will be derived. First, it is shown that this can only be done for linear reciprocal EUT's. Second, it is shown that the equivalence can only be established at a selected number of ports. The currents and voltages induced on any other places of the EUT are radically different for each test. The difference may be as much as 30 dB in the example examined. Third, for the port equivalence to be true the injected sources have to be coherent, that is, produced by the same generator, and have to have specific amplitude and phase relationships. The derivation of the test equivalence shows how the incident field should be established in the radiated tests. It also shows how to obtain the correct amplitude and phase of the injected sources, and where they should be placed. Examples and comparison of the radiated and injected tests will be presented using numerical simulation.

Bio: Prof. Jose Perini, Syracuse University

September 8, 1998: "Annual Social and Business Planning Session "

Abstract: The Santa Clara Valley Electromagnetic Compatibility Society invites all EMC society members and prospective members to attend a social and fun talk on Tuesday 8 September 1998 at the Bold Knight. Hear Bill Ritenour's famous tale on the EMC hazards of filling up at the gas station! The purpose of this event is to promote interaction and discussion about useful topics for the technical sessions to be held during the 1998-1999 season, and to have a good time. The chapter also invites prospective speakers to attend this session and submit their presentation for consideration.

Suggested topics include: measurements (techniques, technology, problems, corrections, calibration); test facilities (shielded rooms, open field test sites, screen rooms, anechoic and semi-anechoic chambers); EM noise sources and studies; Design for reduced noise; ESD; antennas and propogation; EMC standards and regulations; EMC and Signal Integrity issues, and computer aided analysis and design.

May 12, 1998: "The Use of Scanning Receivers in EMI Compliance Measurements" by Werner Schaefer, Hewlett Packard

Abstract: Spectrum analyzers and EMI receivers are both used to make radiated and conducted EMI measurements. Even though the initial design goals for these instruments were considerably different, their hardware architecture is similar in many ways. Spectrum analyzers were initially designed to analyze radar signals, while EMI receivers have always served the purpose of measuring the spectral components of an emission spectrum of an EUT (equipment under test). The first EMI receivers were manually-tuned instruments with analog meters for indicators. Later on, receivers became commercially available that could be automatically tuned to different frequencies and provided a numeric readout of the measured emission amplitude and tuning frequency. Spectrum analyzers, on the other hand, were always swept over the frequency range of interest, and provided a graphical representation of the measured spectrum.

Since both approaches have advantages, most EMC laboratories use spectrum analyzers and EMI receivers to accomplish their measurement tasks. For more than 10 years, spectrum-analyzer-based EMI receivers, called scanning or swept receivers, have become commercially available. This type of receiver combines the advantages of spectrum analyzers and dedicated EMI receivers in a single instrument. However, there are still concerns within the EMC community about the measurement capability of scanning receivers, their compliance with the specifications called out in the various standards, in particular CISPR (International Special Committee on Radio Interference) Publication 16 Part 1, and their suitability for EMI compliance measurements in general. This presentation compares the hardware architecture of a scanning and a traditional receiver, reviews the most important EMI receiver specifications and explains some practical issues related to the stepped versus swept measurement approach, the receiver frequency and display resolution, RF overload detection, and the discrimination between narrowband and broadband signals.

Bio: Mr. Shaefer is the Technical Contributor (EMC) at Hewlett-Packard Company. He has an extensive conducted and radiated emissions measurement practice background, including open area test site qualification and antenna calibration, development of EMI measurement software, and development and teaching of EMC classes at universities. He is an active member of CISPR A (EMI measurement equipment and procedures), ANSI C63 Subcommittee, SAE, IEEE EMC Society, and VDE/Germany. Mr. Schaefer has authored numerous publications on microwave measurement topics in technical journals in Europe, 10 papers on EMI measurement topics, given at EMC symposiums in Europe and USA, and co-authored a book on microwave measurement technology in Germany.

April 14, 1998: "CE Marking for Medical Devices" by John G. Smith, PE, NCE, NELLCOR PURITAN BENNETT, Carlsbad, California

Abstract: Most EMC engineers attending the Santa Clara Chapter of the IEEE are using the EMC Directive as a passport to accessing the European Community. Mr. Smith has been asked to present CE Marking for Medical Devices to provide an appreciation as to what is required of Medical Devices to gain access to this market.

The New Approach Directive for Medical Devices (MDD) has far-reaching consequences for manufacturers and distributors who wish to place a product onto the market of the European Union (EU). Structured differently that either of the EMC or Low Voltage Directives, the MDD is an all-inclusive directive consisting of the following component parts:

  • Product Determination
  • Classification
  • CE Procedure
  • Essential Requirements
  • European Harmonized Standards
  • Risk Analysis
  • EMC Compliance
  • Notified Body Participation
  • Technical Documentation File
  • Declaration of Conformity
  • CE Marking

John will discuss these with us and touch briefly on the changes on the horizon for Medical Devices.

Bio: Mr. Smith began his academic training as an electrical engineer, with a BSEE degree from Pacific Southern University. He has over 25 years experience in medical device and information technology equipment development and certification. John is a Senior Certification Engineer for the NELLCOR PURITAN BENNETT Hospital Division, a registered Professional Engineer and certified EMC engineer. He has a command of the European Directives' for Medical Devices and Electromagnetic Compatibility especially with respect to hazards, risk analysis, test and mitigation for product safety and EMC compliance.

John maintains membership with the AAMI, IEEE and NARTE and participates in the product safety, EMC and biomedical engineering chapters. He has served upon US Technical Advisory Groups for medical device requirements, has presented numerous seminars and papers to peers, colleagues and professional symposia and has authored two publications.

Mr. Smith was the regional EMC manager for ToV Product Service in San Diego prior to NELLCOR and specialized in certification, testing and engineering support for equipment and device manufacturers desiring compliance to domestic and international standards.

Before joining ToV-PS, John was employed with Alcon Laboratories as a member of the technical staff. His responsibilities included mentoring, conceptual and formal design reviews, regulatory compliance and product certification of medical devices for the Surgical Division. He also served as a Program Manager for a series of low cost, portable ophthalmic instruments intended for Europe, Japan and markets of developing countries.

March 10, 1998: "Fun With the Fourier Series" by Franz Gisin, Silicon Graphics

Abstract: Randomly pick up any EMC book or article that covers Fourier Series, and chances are the relationship between the time and frequency domains are explained in terms of either a symmetrical rectangular or trapezoidal waveform centered about the t = 0 axis. While they may serve as excellent introductory examples, they cannot be used to analyze more complex waveforms having unequal rise and fall times, overshoots, and undershoots. Nor can these simple waveforms be used to model more complex scenarios such as the spectral analysis of digital differential drives, where the concept of "cancellation" also requires phase information.

This presentation develops a simple but effective method of obtaining the Fourier Series of complex waveforms, and then analyzes several common problems normally encountered in the EMC field. Topics that will be covered include:

  • Conceptual development of the Fourier Series from a piecewise linear periodic waveform.
  • An analysis of rectangular pulses that shows how decreasing the pulses width often results in increasing harmonic levels.
  • An analysis of symmetrical trapezoidal waveforms that show how a 10 MHz clock can actually have lower harmonic levels than a 1 MHz clock.
  • An analysis of non-symmetrical rise/fall time trapezoidal waveforms that shows how much reduction in harmonic levels one can obtain if only the rise (or fall) time were increased.
  • An analysis of trapezoidal waveforms having overshoots and ringing and how much overshoot and ringing can be tolerated.
  • An analysis of digital differential drivers and how the common perception that differential driven signals are "somehow" less prone to cause emission problems are not always true.

Bio: Franz Gisin has a BS(EE) from the University of Idaho, and an MS(Applied Mathematics) from the University of Santa Clara. He ahs been active in the EMC community for over 20 years, and is currently EMC Manager at Silicon Graphics Inc. He is a senior member of the EMC Society, a member of the EMC Society Board of Directors, and the Steering Committee Chair of EMC'98.

February 10, 1998: "Harmonics and Flicker Requirements in the European Union" by Andy Griffin, CISCO Systems

Abstract: Since the advent of the European EMC directive [89/336/EEC] there have been harmonic and flicker requirements on different products types dependent upon there operating environments. EN61000-3-2 [harmonics] and EN61000-3-3 [flicker] were published and subsequently became legal requirements for the majority of products. Many manufacturers are not assessing their products against these requirements and still shipping products, are they doing this legally? We will discuss the background to the current situation and analyze if these manufacturers are shipping products legally.

Bio: Andy Griffin graduated from college in Nottingham, England in 1985, since that time has worked within the EMC industry. He has worked at Assessment Services, KTL , AWRE Aldermaston, IBM, CISCO Systems Inc (currently EMC Laboratory Manager) and as an independent consultant. In addition he is managing director of EMiSoft ltd, who generate EMC test software, provide EMC consultancy services and are co-authors of the EMC Compliance Manual (with ICC - Telecomm Approval Consultants) providing an in-depth analysis of worldwide EMC requirements for ITE and TTE. He is also a qualified Test Laboratory assessor covering the requirements of ISO 9001, EN45001. He is currently a member of the following EMC committees -ETSI EE4, GEL 210, GEL 210/7 and GEL 210/10 where he provides input into all CISPR/IEC.

January 13, 1998: "Switching Noise in VLSI Packages" by Dr. Richard Wheeler - President Wheeler Enterprises

Abstract: Quarter micron CMOS designs are switching thousands of I/O's at Gigahertz frequencies. Core switching places even greater demands on the power distribution network to the chip. This talk will examine the trends of IC technology from the 70's through the 90's and its impact on feeding power to the chip. It will show how to model core switching currents and will discuss how much bypass capacitance is needed and where to place it. Examples will be shown comparing the relative efficacy of bypass capacitors placed on-chip, buried in the chip package or surface mounted on the chip package. Future trends will also be noted.

Bio: Dr. Wheeler has a Ph.D in Electrical Engineering and Solid State Physics from Brigham Young University, Provo, UT. E.E. department with focus on Solid State Physics. He has over 26 years experience in industrial management, research, and hardware development, including: Bell Telephone Laboratories, Holmdel, NJ, Hewlett Packard Research Labs, Palo Alto, Ca. Presently, he is a management consultant for Hewlett Packard and evaluated multi-divisional VLSI packaging program for future computer products and recommended cost saving alternatives. Currently, he is acting as a technical advisor to a multi-divisional council responsible for coordinating flip chip development procedure across company boundaries and acting as a technical advisor to the Network Division to design CMOS driver/receiver circuits capable of operating greater than 1000 MHz. While at Fujitsu Computer Packaging Technologies, Inc., he managed the R&D activity and played a key role in inventing a new type of interconnect between VLSI chips and PC boards. The new interconnect will allow computer CPUs to operate at clock frequencies above 1000 MHz. He was responsible for the technological design of high speed supercomputers, mainframes and workstations, bipolar and CMOS process and equipment design, and high speed networking: physical layer and OS interface. Dr. Wheeler has authored 16 patents and IEEE Proceedings paper.