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IEEE EMC Society Atlanta Chapter | |
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CHAIRMAN
Scott Proffitt
President
Advanced Compliance Solutions, Inc.
Buford, Ga
770-831-8048
sproffitt@acstestlab.com
UPCOMING ACTIVITIES
Are you ready for some EMC?
June 10th 6:00 PM to 8:00 PM. Join us for a great presentation from Laird Technologies.
Here’s a thumbnail on what the evening will provide, (along with pizza and soft drinks):
Top 10 Considerations for Selecting RF Shielding Materials
By: Gary Fenical, NARTE Certified EMC & ESD Engineer, Laird Technologies
Location: To Be Determined
Synopsis:
RF shielding materials are an important consideration when designing electronic components because these
materials help ensure the electronic device will perform to its optimum functionality. Considering RF
shielding materials at the beginning of the application assures that the right materials are chosen and
that issues can be found and dealt with early on in the process, which saves money and keeps the project
on time. Choosing the right materials upfront ultimately gets the product to market quicker.
This paper will discuss factors to consider when selecting RF shielding materials for an electronic
device. Taking these factors into account can save time and money and help assure peace of mind when
designing an electronic device.
Considerations expanded upon are:
1. Operating Frequency
2. Attenuation Performance
3. Materials Compatibility/Corrosive
4. Environmental
5. Compression Load or Force
6. Fastening/Mounting Methods
7. Nuclear, Biological, or Chemical
8. Cycle Life
9. Space/Weight Considerations
10. Recyclability
PAST ACTIVITY
On October 23, 2007, Jeff Bruce of Steward, the Signal Integrity Products
Division of Laird Technologies, gave a presentation titled Ferrites and Electromagnetic
Compatibility at the Motorola test labs in Lawrenceville. The presentation discussed the root
cause of most EMI noise and how it can be reduced. Jeff discussed Hysteresis, types of chokes,
Spice Models and Curves of Z, R and X varieties. Jeff discussed the Types of Parts: SMT,
Common Mode Chokes, Differential Mode Chokes, Cable Cores, Connector Plates, Inductance vs
Impedance, Typical Impedance Curve, Chip Bead Construction, Design Considerations for Current,
Core Saturation, Differential Mode vs. Common Mode and Temperature. We had great attendance
with about 30 people.
On August 7, 2007, Jason Smith of AR Worldwide (Amplifier Research) presented on RF Immunity testing,
the recent changes, and how it applies to your business. RF Immunity testing is a requirement for
CE Marking commercial products bound for the European
Union. But the test is also a necessity for assuring a quality product in our ever increasing
Radio Frequency filled world. The presentation discussed changes to IEC 61000-4-3 Ed. 3 which
include a significant increase
in the test frequency range, new limitations on RF power amplifier linearity and harmonic content,
and a requirement for the material used for the test table. It also went through the process and
calculations of selecting equipment for radiated immunity testing. We had great attendance with
about 35 people in the meeting room overlooking the lake at the Scientific Atlanta (Cisco)
campus in Lawrenceville.
On October 10, 2006, the EMC Industry renowned Dr. Clayton Paul spoke to us at an all day
event held on the Georgia Tech Campus. Dr. Paul’s credentials are way too long to list here,
but among the many, he is a Distinguished Lecturer, popular EMC author, and IEEE
Electromagnetics Award winner. This was a “mini-symposium” format, with lecture
and exhibitors. The Atlanta chapter is grateful to Dr. Paul for this educational presentation.
On August 29, 2006 Terry Welsher, from Dangelmayer Associates, LLC presented on
“Impact of the Technology Trends On ESD Sensitivity of Components" at EMS Wireless
in Norcross. ESD failures are occurring with increasing frequency, in unexpected ways and at
new locations in the manufacturing process due to the industry wide trend towards
ultra-sensitive (ESD Class 0) components. This is being driven by several technology
trends and market forces. Device design experts are experiencing increasing difficulties
designing-in adequate ESD protection. Even wafers are now failing due to ESD damage
and mathematical models indicate these failures will increase with the scaling trends.
Industry standards are changing much too slowly to drive change in design and factory
controls. Greater attention to neglected forms of ESD such as the Charged-Device Model
must be addressed to maintain high yields. These trends cut across the semiconductor,
disk drive, flat panel, RFID and other industries. State of the art ESD monitoring
techniques including EMI-based event detection are playing a key role in the location of
ESD events in manufacturing.
On April 25, 2006, Sam Wismer from Advanced Compliance Solutions, Inc. spoke on EMC Regulatory
Arrangements in the U.S. and the European Union at Scientific Atlanta, a Cisco Company, in
Lawrenceville. He discussed the regulatory arrangements for various types of equipment in
the US and the EU. The process of selecting standards, applying proper test levels and
limits, choosing the proper authorization route and obtaining final approval is often
misunderstood by manufacturers. This presentation discussed the equipment authorization
procedures for the U.S. including certification, verification and DoC as well
as discussed the hierarchy of the European Union requirements including Directives, product
standards and basic standards, and how they are related.
On September 29, 2005, Greg Abernathy of Practical Engineering, PC, spoke on Practical Signal
Integrity and EMC Design Techniques.
He described how digital design speeds have increased to the microwave range in recent years
and continue to reach into all of our lives. With this development, Signal Integrity design
has emerged as requiring consideration. However, Signal Integrity and EMC Design should not be
considered separate disciplines. This presentation discussed common goals and techniques that will
allow a design engineer to discuss the relevant issues from both perspectives and identify
possible trade-offs that may be encountered.
Greg Abernathy, president of Practical Engineering, PC, received a BS degree in electrical
engineering from Auburn University in 1985. In 1990, he became a NARTE certified electromagnetic
compatibility engineer and in 1994 obtained his Professional Engineering license. He has been
a member of the IEEE EMC Society since 1984 and has worked in various areas of electromagnetics
for Lockheed Martin, Compaq Computer Corp. and L-3 PHOTONICS. He co-authored 5 awarded patents
in the areas of ESD, Signal Integrity, Antennas and Optical Systems with additional patents
pending. His experience includes high speed signal integrity design, EMC/ESD design,
Lightning design, antenna design, RF and Optical system design. Mr. Abernathy is also
currently working for L-3 PHOTONICS as an Electro-Optical Engineer Senior Staff.
On June 7, 2005, Jeff Bruce of Steward spoke on “Ferrites for EMI” covering
I. EMI BASICS
II. FERRITE BASICS
III. DESIGN CONSIDERATIONS
IV. MATERIAL & PERFORMANCES
V. PART SIZE & CONFIGURATION
On April 26th, 2005, the chapter presented a half-day Technical Seminar with Demonstrations on
"To Improve The Accuracy Of EMC Measurements"
The material presented was fabulous, the discussions lively, the camaraderie good and the food
(shrimp, pasta, steak skewers, etc. even though it didn’t last very long!) was great!
There were about 55 in attendance.
Rodger Gensel, AR Worldwide presented "RF Conducted and Transient Disturbance Testing." He
reviewed the background of RF conducted immunity and transient disturbances such as EFT
(Electrical Fast Transients), surge, ESD (Electrostatic Discharge) and power failure.
A brief look into each of the phenomena was given and the devices which are utilized to
simulate these disturbances. An overview of the specifications behind these disturbances
was also provided. Gensel is the technical contact/marketing specialist for the EM Test
Transient Generators product line at AR Worldwide.
Sam Wismer and Steve O’Steen, Advanced Compliance Solutions presented on "Accuracy of EMC
Measurements: The Test Lab Perspective." They addressed the EMC laboratory’s perspective on
“How” to improve EMC measurements, reflecting on the input of the Big Three as used “on
the lab floor”. Emphasis was placed on measurement accuracy and what it means in the lab/client
relationship, as a risk assessment factor for the client, to measurement uncertainty
and as an overall test lab quality characteristic. Sam Wismer is the Technical Director and
senior engineer at Advanced Compliance Solutions, Inc. Steve O’Steen is the EMC Laboratory
Manager at Advanced Compliance Solutions, Inc.
Vince Rodriguez, ETS-Lindgren presented "Anechoic Chamber Design, Rectangular Antenna Ranges:
A Case Study." The measurement of antenna patterns is becoming an important issue, not only
in the defense industry but also in the fast growing wireless communications industry. He
discussed the pattern and far field concepts and different antenna ranges that can be used for
pattern measurement. He then concentrated on direct illumination rectangular APM chambers and
illustrated by presenting a case study. Dr. Rodriguez is an RF and Electromagnetics engineer at
ETS-Lindgren.
James Young, Rohde & Schwarz presented “The Spectrum Analyzer versus The EMI Receiver”
(advantages and disadvantages). The problems and benefits of using low noise amplifiers
for increased sensitivity was reviewed. James Young is the sales and marketing manager for
Rohde & Schwarz EMI products in the Americas.
On Tuesday, February 22nd, 2005, Mike Oliver, V.P. Electrical / EMC Engineering, MAJR Products
Corporation, presented to our meeting held at Scientific Atlanta in Lawrenceville, GA.
Mr. Oliver is in charge of new product development, EMC product implementation, and quality
management. His expertise is in EMI/RFI shielding technology with a background in electronics,
military shelter electrical systems, and military high power antenna / radome design.
He presented on calculation of open aperture attenuation loss. This led into board level
shielding design / test and possible honeycomb vent panel shielding products and applications.
On October 19th, 2004, Jason Smith of Amplifier Research presented an introduction to, and discussion
about Bulk Current Injection (BCI) Testing. These generators perform testing to the various
Conducted Immunity Standards/Specifications. The presentation was held at the Nordson Corporation
in Duluth, GA. This sometimes very difficult test is performed in all industries such as Military,
Automotive, Medical and Commercial. This one test can be problematic and meeting the requirements
needs to be designed into the product before final testing, where retro fixes can become costly. He
discussed what equipment is needed to perform this test and the different setups that are used.
He also discussed the benefits of automating the test in order to dramatically shorten the
time of calibration, testing, and reporting.
On August 24, 2004, Greg Conley of Technical Systems Integrators based in Casselberry, FL gave an
introduction to Mentor Graphics Hyperlynx software for PCB radiated EMI prediction at Altea Therapeutics
in Tucker, GA. The basic Hyperlynx software accepts PCB layout data and performs post-layout verification.
It is effective for clock and edge rates up to about 1 GHz. You can add the crosstalk module,
or only the EMC module. Or bundle all three modules. They also have software that can be used
for pre-layout predictions based on topology and board stack, and they have the "GHz" version
of post-layout verification that extends capability up to many GHz and adds eye diagrams and
frequency dependent vias.
On May 20th, 2004, Dortch Walker, Field Applications Engineer with Rohde-Schwarz, spoke on "EMI
Receivers vs. Spectrum Analyzers In EMI/EMC Applications" at Motorola ESG in Lawrenceville, GA. This
presentation dealt with the differences between test receivers and spectrum analyzers and the proper
application of both in EMI/EMC testing.
On March 16, 2004, the industry renowned Daryl Gerke of Kimmel Gerke consultants, out of Phoenix, AZ,
spoke to our group. The topic was:
How to Design To Fail FCC and CE Tests... in 20 Easy Steps
It was a light-hearted look at 20 EMI common problems from a different perspective. As the old saying
goes, "Oscillators won't, but amplifiers will." What if we turned things around, and actually tried
to fail EMI tests. This approach got a lot of chuckles, and the group got into the spirit by adding
further suggestions. Daryl's talk provided some good technical information on EMI.
The chapter and the participants are indebted to Daryl for his fun and informative presentation and all
who took advantage thank him.
Daryl Gerke also gave a three day seminar during his stay in Atlanta. The EMC Society had no formal
sponsorship or relation to the seminar. Full information on his seminar schedule can be found at
the Kimmel-Gerke website http://www.emiguru.com/seminartek.htm.
Darryl and the Group
Darryl presenting one of his humorous slides.
In mid-October 2003 we held EMC-Fest, a day long tutorial with the industry renowned Dr. Clayton Paul presenting EMC concepts. The chapter and the participants are indebted to Dr. Paul for his outstanding presentation and all who took advantage thank him for his book signings. The chapter also thanks past chair Janet Luo for her efforts in organizing that event.
Scott Proffitt, Present Chair, left; Clayton Paul, second from left; Janet Luo, past Chair, second from right.
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