The Santa Clara Valley IEEE EMC Society announces its March 10th Meeting.
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
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 has 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.
(Note: I am forwarding this to the group for Hans Mellberg who normally
makes these announcements).
