1995 Meetings

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

December 12, 1995: "Lightning and Transients Protection" by Dr. Norman Violette

Abstract: The presentation will cover a wide range of lightning and transient related topics ranging from the Statue of Liberty Lightning Protection Project to circuit level protection devices. Dr. Violette will start the presentation with an overview of lighning basics, the physics of direct and indirect strikes, and how lightning can couple and interact with with power and signal lines. He will then progress to protection methods at the equipment level and cover such areas as design waveforms, and the advantages and disadvantages of various protection components and devices. Also included will be a general discussion of system level design considerations such as protection device coordination. At the conclusion of the presentation, he will describe the techniques used to provide lightning protection for the Statue of Liberty.

Bio: Dr. Norman Violette is one of the leading authorities on lightning and lightning protection in the United States. He received a BEE from Rensselear Polytechnic Institute, an MBA from Auburn University, and a PhD (EE) from North Carolina State University. He is a Registered Professional Engineer in the state of Virgina, and a member of the Board of Directors of the Lightning Protection Institute. He is a Distinguished Lecturer in the IEEE EMC Society.

November 14, 1995: "Calibration Of Fully Anechoic Rooms And Correlation With Oats Measurements" by Roger A. McConnell and Clark Vitek, CKC Laboratories, Inc.

Abstract: Fully anechoic rooms may gradually replace open area test sites as the preferred type of testing facility. The fully anechoic room offers several advantages over the open area test site: Immunity to high ambient signals, the capability of being located in metropolitan areas close to those needing testing facilities, the ability to obtain maximized emissions at a fixed antenna height, and the capability of being used for both emissions and immunity testing.

Open Area Test Sites are required by the FCC to meet the Normalized Site Attenuation (NSA) Standards published in ANSI C63.4. CISPR 22, Second Edition also provide NSA values for OATS calibration. Comparable NSA standards for free space, and thus for an ideal fully anechoic chamber, are readily calculated using the following equations NSA = 278.9/(Fm*Ed) where Fm is the measurement frequency and the field strength Ed is calculated from : Ed = Sqrt(49.2)/D where D is the distance separating the two antennas. These two equations can be used to generate free space NSA values for any test distance desired.

In addition to calibrating the fully anechoic room, in order to be used for emissions measurements, it is necessary to demonstrate that the radiated emissions measured from an EUT in the fully anechoic chamber are equivalent to emissions measurements made on the same EUT on an OATS. Methods of demonstrating this equivalency are presented, along with actual measured data.

Bio: Roger McConnell has been with CKC Laboratories. Inc. in Mariposa, CA since 1986. His primary EMC activities have been in open field range calibration, anechoic room performance, and energy transfer in EMP. He has been a member of the Society of Automotive Engineers AE4R Subcommittee which has been advising the FAA in connection with the threat to aircraft from high energy rf fields. At CKC, he has engineering responsibility for the operation of the Mariposa Semi-Anechoic facility.

Prior to his employment at CKC, Mr. McConnell was employed for 24 years at the Stanford Linear Accelerator Center in technical support of high energy physics research. He specialized in the design of very high power cw rf systems, accelerator cavities and phase stable transmission lines. He has coauthored a number of papers relating to particle accelerator radio frequency systems which have appeared in the IEEE symposiums on Nuclear Science, and has authored six papers on open field range calibration and EMP which have appeared in the IEEE Symposiums on EMC. Mr. McConnell is a graduate in electrical engineering (1958) from the University of California at Berkeley, and holds the position of Senior Consultant at CKC Laboratories.

Clark Vitek is a member of the IEEE and AAMI, and has published articles on EMC at symposiums and in industry periodicals. His present position at CKC Laboratories is Consulting EMC Engineer / Pacific Northwest Regional Manager based at CKC's Hillsboro, Oregon facility. Mr. Vitek has overseen the development of two of CKC's Fully Anechoic Chambers: the 3.0m x 7.5m x 3.0m (w,l,h) chamber in Fremont, CA and the 6.0 x 8.0 x 3.0 (w,l,h) chamber in Hillsboro. He is a graduate in Electrical Engineering from the University of California, at Davis, with course work emphasis in RF and Microwave design.

October 10, 1995: "Power, Ground and Signal 'Bounce' in High Speed Digital Circuitry" by Dr. Jim Parker, Fujitsu Computer Packaging Technologies, Inc.

Abstract: High speed digital circuits (particularly CMOS) demand short-duration current pulses while switching. This current must be provided by a (preferably very low impedance) power distribution network. The resulting I*Z voltage "bounce" can degrade normal circuit operation. Besides causing a momentary "brown out" of the power supply voltage, this transient competes with cross talk in consuming an allowable noise budget for the circuit design. Assessing these effects quantitatively requires accurate electrical models of the power and ground planes. These two planes are "accessed" (i.e. - excited electromagnetically) from the physical network's interconnect vias. Measured TDR and TDT (Time Domain Transmission) data having 50 picosecond rise time is utilized to illustrate the propagation and subsequent reflections of bounce voltage throughout a rectangular pair of power-ground planes. A corresponding analytical model is then developed for the open circuit impedance parameters between any pair of vias. When these frequency domain network parameters are inverse Fourier transformed back into the time domain, excellent agreement with measured data is demonstrated. The observed wave-physics phenomena is related to the simpler network port voltages and currents by utilizing radial transmission line concepts. These concepts are systematically developed starting with lineal transmission lines. Insight into the various physical mechanisms is stressed, while maintaining rigorous final results.

Bio: Jim Parker is a Senior Research Scientist at Fujitsu Computer Packaging Technologies, Inc., where he specializes in electromagnetic analysis and modelling. After completing BSE, MSE and PhD degrees (all in EE) at the University of Michigan, he worked 11 years for Bell Telephone Laboratories in New Jersey. In 1981 Jim formed an EMC Group at Data General Corp., and then in 1984 the EMC Engineering Department at Apollo Computer, Inc. He remained at Apollo (and subsequently Hewlett-Packard) for 7 years, specializing in both Regulatory and Signal Integrity issues. Jim is a Senior Member of the IEEE, Chairs the EMC Society's Technical Committee on Interference Control, and is a Registered Professional Engineer in the State of New Jersey.

September 11, 1995: "Annual Social and Planning Session"

Abstract: The purpose of this event is to promote interaction and discussion about useful topics for the technical sessions to be held during the 1995-1996 season. 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.