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Presenters
: Bruce Archambeault -
Bio
Mat Aschenberg
Date :
May 20th 2003
Location : Front
Range Community College
What we saw:
28 members and non-members of
the IEEE were treated (subjected to?) not one - not two but three
presentations at our May 20th meeting. The meeting was kicked
off by Mat Aschenberg of Echostar Technologies with a presentation
entitled "Predicting the Future - The GTEM tamed?" In his
presentation, Mat addressed the age old ( well ~25 yrs anyway) problem
of correlation. All EMC engineers are familiar with the problems
associated with comparing data between OATS sites let alone between a
non-traditional site -such as a GTEM and an OATS. Mat proposed a new
ways of looking at the problem . Instead of trying for a point for
point correlation, why not use statistics to predict the probability
of an EUT passing or failing? The presentation generated a great deal
of discussion and served as a nice warm up for the main event.
After a short break Dr
Archambeault, in another example of the stamina of our Distinguished
Lecturers!, launched into the mysteries of EMI in printed circuit
boards and that other mysterious technology - the humble decoupling
capacitor. Bruce focused the group very strongly on what was really
important in EMI - current - NOT voltage. Bruce then put up a slide
that displayed all the variants around the word ground and stated
quite categorically that the only thing ground was good for was
planting potatoes. Bruce was encouraging us to regard ground as a
return path instead. Multi-layer PCBs typically contain a number of
different high speed signals. Successful routing of all these signals
often require some of the standard EMC “rules” to be violated for
example trace density forcing traces to cross splits. A detailed
presentation on the effectiveness of decoupling capacitors then
followed which led nicely to that other myth laden area of EMC -
Decoupling. While there has been a lot of attention on this topic,
there is still significant confusion about the best strategy for
decoupling. This part of the talk focused on the sources of noise that
the decoupling capacitors are intended to control, and the physics
involved in the noise propagation, and how to properly analysis the
decoupling capacitor performance. Using simulation Bruce showed
that the analysis must be performed in BOTH the time domain and
the frequency domain. The frequency domain analysis is a steady
state analysis, and will determine resonances, which are most useful
for EMI emissions analysis. The time-domain analysis is a
transient analysis and will help determine how well the current is
delivered to the IC, and ultimately, how large (or small) the
generated noise pulse will become. Real-world
examples of measurements, as well as computer simulations were used to
demonstrate the optimal decoupling
Speaker:.
Bruce Archambeault, Ph.D
Dr. Bruce Archambeault is a Senior Technical Staff
Member at IBM in Research Triangle Park, NC. He received his B.S.E.E
degree from the University of New Hampshire in 1977 and his M.S.E.E
degree from Northeastern University in 1981. He received his Ph. D.
from the University of New Hampshire in 1997. His doctoral research
was in the area of computational electromagnetics applied to
real-world EMC problems.
In 1981 he joined Digital Equipment Corporation and through 1994 he
had assignments ranging from EMC/TEMPEST product design and testing to
developing computational electromagnetic EMC-related software tools.
In 1994 he joined SETH Corporation where he continued to develop
computational electromagnetic EMC-related software tools and used them
as a consulting engineer in a variety of different industries. In
1997 he joined IBM in Raleigh, N.C. where he is the lead EMC engineer,
responsible for EMC tool development and use on a variety of
products. During his career in the U.S. Air Force he was responsible
for in-house communications security and TEMPEST/EMC related research
and development projects.
Dr. Archambeault has authored or co-authored a
number of papers in computational electromagnetics, mostly applied to
real-world EMC applications. He is currently a Board of Directors
member of the Applied Computational Electromagnetics Society (ACES)
and the IEEE EMC Society. He has served as a past Associate Editor
for the IEEE Transactions on Electromagnetic Compatibility. He is the
author of the book “PCB Design for Real-World EMI Control” and the
lead author of the book titled “EMI/EMC Computational Modeling
Handbook”.
Speaker
Contact Information:
Bruce Archambeault, Ph.D.
Senior Technical Staff Member
IBM
PO Box 12195
3039 Cornwallis Road
Dept 18DA B306
RTP, NC 27709
Phone: (919) 486-0120
Email:
barch@us.ibm.com
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