Rocky Mountain Chapter EMC Society |
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Our last meeting was.. How to Div Grad Kink and Curl Electrons Into Generating Unwanted Radiated Emissions Presenter Franz Gisin Manager, EMC/SI Design Sanmina Date : Feb 26th 2002 Location : TUV Product
Service, 5541 Central Avenue Boulder, CO 80301-2846 Times : 6:30 - 8:00pm What we saw: Anyone who has spent any length of
time wandering around within the EMC discipline, will, on occasion, take time
out to pause and reflect on exactly what is it about pushing electrons around
on conducting materials that causes them to generate propagating
electromagnetic waves in their wake. We already know the size of the
structure plays an important role.
Structures excited at their natural resonant frequencies radiate at
higher levels. We also know
different shaped structures, whether they are optimized for maximum radiation
- for example an antenna, or optimized for minimum radiation - for example a
collection of information technology equipment assembled on a turntable for
an EMC emission test, radiate with different efficiencies. But if we dig a bit deeper, we cannot help but wonder if
some portions of the structure radiate more efficiently than others. For example, electromagnetic fields
from a simple resonant dipole antenna can be mathematically expressed as a
sum of three point sources located at the ends and the middle of the
dipole. The implication is that
radiation along the dipole elements is not uniform. If this is so, then we must ask ourselves what intrinsic
qualities inherent in the shape of a structure causes electrons in some areas
of the structure to generate higher levels of electromagnetic radiation than
others. If we can gain a better understanding of the
relationships between structure size and shape, electrons in motion, and
propagating electromagnetic waves, then we can become better EMC and Signal
Integrity engineers by not designing in these kinds of structures into our
products. We know Maxwell's equations
accurately describe all electromagnetic phenomena, and so a good starting
point is to disassemble these deceptively compact equations and see if we can
gain any insight by looking at them in richer detail. We can also gain understanding by
modeling and simulating structures that we often encounter in the EMC
profession, for example, printed circuit boards and their associated traces,
cables, and electronic enclosures.
From these two approaches we can then formulate some practical
"best design practices" that will help us build products that
radiate with minimum efficiency. Speaker:. Franz Gisin received his BS(EE) from the University of Idaho in 1972, and his MS(Applied Math) from Santa Clara University in 1986. Franz has been active in the EMC field for over 25 years. He is currently Manager of EMC and Signal Integrity Design at Sanmina, the worlds largest EMS manufacturer of high performance printed circuit boards and backplanes. He is a past IEEE EMC Society Distinguished Lecturer, and past member of the IEEE Board of Directors. Currently he is vice-chair of TC-10, Signal Integrity, and Steering Committee Chair of the 2004 International EMC Symposium, Santa Clara, CA. Speaker Contact Information: Franz Gisin Manager,
EMC/SI Design Sanmina 355 East
Trimble Road San Jose
CA 95131 Tel: 408
474-1320
Fax:
408 474-1318 |