1997/1998 Monthly Chapter Meeting Notices

September '97 Meeting Notice

When/Where
Tuesday, September 9, 1997. The Bold Knight of Sunnyvale, 769 North Mathilda Ave Sunnyvale, CA. 5:00 p.m. - 9:00 p.m.
Topic/Speaker
Annual Social and Business Planning Session
Details
The Santa Clara Valley Electromagnetic Compatibility Society invites all EMC society members and prospective members to attend the annual social and planning session on Tuesday, September 9 from 5:00 to 9:00 p.m. The meeting will be held at The Bold Knight in Sunnyvale.

Refreshments and a buffet dinner will be hosted by the SCV EMC Chapter, after which the new officers will be introduced and each will provide a short presentation on their plans for 1997-98. It would be greatly appreciated if you could call either Geoff Day at 408-756-9919 or Mike Royer at 415-780-4218 if you (and your spouse or significant other) plan on attending.

The chapter also invites prospective speakers to attend this session and submit presentation outlines 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; electrostatic discharge; antennas and propagation; EMC standards and regulations; and computer aided analysis and design. Anyone interested in presenting an outline of these or other appropriate topics should contact Geoff Day at (408) 756-9919.

October '97 Meeting Notice

When/Where
Tuesday, October 14, 1997. Building 157, Lockheed Martin, 3rd Avenue Sunnyvale, CA. 7:30 p.m. - 9:00 p.m.
Topic/Speaker
The Resurrection of an Absorber Lined Chamber Ronald Pratt, NCE, Hewlett Packard Co., Santa Clara, CA.
Details
The quality of a test site is based on demonstrating conformance of measured Normalized Site Attenuation (NSA) to ideal values published in ANSI C63.4. Celebration is appropriate if the data falls within the +/- 4 dB limits but more work will be required if the site fails to meet these limits. This paper describes an extension of the existing test process that may prove useful for evaluating the performance of a site. Further analysis of the data can help identify the root cause of the problem.

The method was successfully applied to develop a strategy for improving the performance of the ten meter absorber lines chamber at the Hewlett Packard Hardware Test Center in Cupertino. An overview of the analysis of the site and a discussion of the retrofit will be presented.

Ron Pratt joined the Hewlett Packard Company in 1967 and spent most of his career developing microwave instruments for signal generation, network analysis as well as power and noise figure measurements. EMC was always an important part of that work and for the last several years he has focused on those problems.

Ron received his BSEE from New Jersey Institute of Technology in 1967. For almost 20 years Ron taught a very successful microwave measurements course at Foothill College. He is a contributing author to the Reference Data Engineers: Radio, Electronics, Computer, and Communications and the Electronic Instrument Handbook. Ron is a member of IEEE EMC Society and is a NARTE certified EMC Engineer.

November '97 Meeting Notice

When/Where
Tuesday, November 11, 1997. Building 157, Lockheed Martin, 3rd Avenue Sunnyvale, CA. 7:30 p.m. - 9:00 p.m.
Topic/Speaker
Understanding Intrinsic Printed Circuit Board Capacitance & Decoupling Methodology Neilus O'Sullivan, Sun Microsystems, Menlo Park, CA.
Details
Summary: Much investigation has been carried out into the area of intrinsic board capacitance of power distribution systems on multi-layer printed circuit boards (PCBs). While its benefits are broadly understood, very little tangible evidence exists as to whether or not it provides an effective solution for combating radiated EMI in complex state of the art computer systems.

In this presentation, the EMI characteristics of a densely packed high speed computer motherboard involving clock and bus speeds up to 200MHz with signal rise times in the order of 400 pico-seconds is analyzed extensively. Actual measured comparisons of radiated emissions and power bus transfer impedance are presented for the original motherboard and for the case of the motherboard with additional power and ground planes included. A discussion of general decoupling methodology for multi-layer boards will also be presented.

Biography: Neilus O'Sullivan received his B.Eng. degree from the University of Limerick in Ireland in 1989 and his Ph.D degree in electromagnetics from the same university in 1995. He has worked for Analog Devices B.V. as Test Characterisation Engineer and in 1989 joined automotive electronics manufacturer, Kostal Ireland as Research and Design engineer. From 1991 to 1995 he worked as consultant engineer to the broadcast industry in Ireland. At present he is employed by Sun Microsystems as EMC engineer at their Menlo Park facility. He has published a number of papers and presentations on various aspects of EMI, but his main area of interest is that of EMI control at printed circuit board level.

December '97 Meeting Notice

When/Where
Tuesday, December 9, 1997. Building 157, Lockheed Martin, 3rd Avenue Sunnyvale, CA. 7:30 p.m. - 9:00 p.m.
Topic/Speaker
EMC Research Projects - Radiated Field Coupling to Signal Cables, Power Circuit Cross Coupling Mary Wilson, SFSU/Bay Networks, Michael Mack SFSU, Edwin Salgado, SFSU/Silicon Graphics Inc. - Intro Dr. Pantic-Tanner, Director, SFSU School of Engineering
Details
On December 9, the Santa Clara Valley Chapter of the IEEE EMC Society will hear presentations on two EMC research projects being carried out by the San Francisco State University (SFSU) Electromagnetics Group.

In the first presentation, the effects of radiated fields inducing unwanted common mode and differential mode currents onto signal cables are evaluated. Digital and analog control systems are exposed to the external electromagnetic noise produced by electrostatic discharge, EM fields from transmitters, and other sources. As a result the systems can start malfunctioning and the susceptibility problems arise. One of the main mechanisms of coupling of these external fields to the control systems is through the cables and wiring that act as receiving antennas. In this presentation the modeling results of two-wire lines excited by a uniform plane EM wave are analyzed using three different models. A lumped parameter model which is valid for lower frequencies and yields a simple analytical solution that is suitable for estimation purposes. For higher frequencies a transmission line model and an antenna model are used to accurately represent resonant behavior. This topic is being presented by Mary Wilson and Michael Mack.

In the second presentation, the effects of power supply switching noise on power distribution traces coupling onto adjacent signal lines are evaluated. Many state of the art microprocessors and ASIC integrated circuits are now powered by voltages that are less than the standard 5 VDC. With this reduced operating voltage, the susceptibility of the signal lines to noise increases. At the same time, these new operating voltages require on-board DC to DC converters that generate a substantial amount of switching noise. This switching noise can couple onto the signal lines, causing the system to malfunction. The noise generated can also have substantial harmonic content that can excite resonant structures within a system, causing it to exceed EMC conducted and radiated emission limits. Normally, power is distributed via power and ground planes in printed circuit boards. But because many of the circuits connected to these low voltage microprocessors and ASCII still operate at a nominal 5 volts, adding an extra low voltage plane adds cost, so this is not always a viable solution. The lowest cost solution is to route the low voltage power for the micro-processors and ASICs through wide traces on the same layers that contain signals. This increases the coupling efficiency between the power traces and adjacent signal traces. In such cases, one can use traditional trace to trace crosstalk coupling models to analyze the problem. This presentation discusses several rules for circuit board design that minimizes this interference. This topic is being presented by Edwin Salgado.

Michael Mack is a senior student majoring in Electrical Engineering at San Francisco State University. Michael has worked for several years in the communication and professional audio field as an technician and sales engineer. He has also worked as an intern with an acoustical engineering firm to develop software programs used to calculate noise criteria curves for HVAC systems.

Mary Wilson is an SFSU senior student majoring in Electrical Engineering with special emphasis on communications. She is also a full time EMC engineer at Bay Networks, where her emphasis is MOM and SPICE modelling of radiated emissions from cable arrays and microstrip geometries. She has also been an Electronic Technician for 8-years including 4-years in the United States Coast Guard working with RADAR systems.

Edwin Salgado is an SFSU senior student majoring in Electrical Engineering and Computer Science with a minor in Mathematics. Edwin has worked as an intern in the AT&T; Communications group writing code to simulate two antennas for wireless communication systems, and as an intern in the VSG EMC group at Silicon Graphics using HP VEE, NEC/INCASES Method of Moments, and Cray Research LC Finite Difference Time Domain modeling tools to do EMC computations as well as assist EMC engineers with performing EMC measurements. Edwin is currently working as an intern at Silicon Graphics in the Graphics Software Group as an Operating System Software Debugger.

January '98 Meeting Notice

When/Where
Tuesday, January 13, 1998. Building 157, Lockheed Martin, 3rd Avenue Sunnyvale, CA. 7:30 p.m. - 9:00 p.m.
Topic/Speaker
Switching Noise in VLSI Packages Dr. Richard Wheeler - President Wheeler Enterprises
Details
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.

BIOGRAPHY: 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.

February '98 Meeting Notice

When/Where
Tuesday, February 10, 1998. Building 157, Lockheed Martin, 3rd Avenue Sunnyvale, CA. 7:30 p.m. - 9:30 p.m.
Topic/Speaker
Harmonics and Flicker Requirements in the European Union Andy Griffin, CISCO Systems
Details
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.

BIOGRAPHY: 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

March '98 Meeting Notice

When/Where
Tuesday, March 10, 1998. Building 157, Lockheed Martin, 3rd Avenue Sunnyvale, CA. 7:30 p.m. - 9:30 p.m.
Topic/Speaker
Fun With the Fourier Series Franz Gisin, Silicon Graphics
Download the handout
Details
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:

o Conceptual development of the Fourier Series from a piecewise linear periodic waveform.

o An analysis of rectangular pulses that shows how decreasing the pulses width often results in increasing harmonic levels.

o An analysis of symmetrical trapezoidal waveforms that show how a 10 MHz clock can actually have lower harmonic levels than a 1 MHz clock.

o 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.

o An analysis of trapezoidal waveforms having overshoots and ringing and how much overshoot and ringing can be tolerated.

o 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.

BIOGRAPHY: 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.

April '98 Meeting Notice

When/Where
Tuesday, April 14, 1998. Building 157, Lockheed Martin, 3rd Avenue Sunnyvale, CA. 7:30 p.m. - 9:30 p.m.
Topic/Speaker
CE Marking for Medical Devices John G. Smith, PE, NCE, NELLCOR PURITAN BENNETT, Carlsbad, California
Details
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:

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

Biography: 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.

May '98 Meeting Notice

When/Where
Tuesday, May 12, 1998. , Auspex, 2800 Scott Blvd. Santa Clara, CA. 7:30 p.m. - 9:30 p.m.
Topic/Speaker
The Use of Scanning Receivers in EMI Compliance Measurements Werner Schaefer, Hewlett Packard
Details
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.

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.

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Last modified: 18 DEC 97 [email protected]

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