SPRING2

Why do many digital circuit designers have trouble with basic EMC concepts? Be sure to read Howard Johnson’s article in this issue.

2. Digital circuit designers tend to view the world differently than EMC engineers

We use Dr. Johnson’s book, High-Speed Digital Design: A Handbook of Black Magic as the main text in our High-Speed Digital Design course at UMR. It’s a well-written and interesting text with useful information for both digital designers and EMC engineers. As the title suggests, digital designers do not always feel that the laws of physics apply to high-speed circuit design. The same can also be said of many EMC engineers. After all, how many EMC laboratories don’t have a rubber chicken (or similar tool-of-last-resort) squirreled away in a secret place?

Nevertheless, as Dr. Johnson points out in his article, digital design engineers view things differently than EMC engineers. To further illustrate this point, I asked one EMC engineer and two digital designers to briefly describe their experiences in the EMC lab. Their responses are printed below. I had to edit them a little to remove profanity and identifying remarks. (They wished to remain anonymous for obvious reasons.) I also reduced their responses to7-or-8-syllable rhyming phrases. Other than that, they are just as I received them.

Set the unit on the table.
Then connect the power cable.
Boot it up if you are able.
Wait until the level’s stable.
Check the spectrum analyzer.
Watch the peak spout like a geyser.
Find the marker. Utilize her.
Quantify the noisy riser.
If the peak’s above the line,
Now’s the time to redesign.
Grab some copper tape and twine.
This is when you really shine.
Reach into your bag of tricks.
Add a ferrite, maybe six.
Try to find that perfect fix,
Like the one in ’86.
Keep close tabs on where you’ve been.
When the peak is down by ten,
Have a cup of coffee, then
Move the cable. Start again.

After months of toil and sweat,
This is my best product yet.
All objectives have been met.
One approval still to get.
This design, from my perspective,
Is quite fast and cost-effective.
Now you say that it’s defective.
What’s this EMC Directive?
Your lab’s very interesting.
Let’s begin the EM testing.
Yes, I see those peaks are cresting.
Just what is it you’re suggesting?
Your demands are quite unyielding.
I don’t like this question fielding.
Or this talk of EM shielding.
What’s that copper roll you’re wielding?
My design was working great.
Now you’ve slowed down every gate,
Added parts and increased weight.
I might miss my shipping date!

Please look over my design.
It won’t ship ‘til ‘99.
But I want an early sign.
Please tell me that all is fine.
I’ve reduced the lengths of traces.
Put small caps in lots of places.
Hope I’ve covered all the bases.
Bless my board with all your graces.
Yes! The system is quite good.
Passed your tests, as it well should.
Please stop cheering, if you would.
Let’s tell no one, understood?
If my management should hear,
The reward would be severe.
For the rest of my career,
I would be an EMC’er.

Ouch! That last rhyme hurt. Hope to see all of you (EMC engineers and digital designers alike) at the 1998 IEEE EMC Symposium in Denver this August!

On December 2, 1997, Lockheed Martin Aeronautical Systems (LMAS) hosted a meeting of the Joint EMC/IM Society Atlanta Chapter. There were 31 attendees from 13 different local companies. The meeting opened with an hour long presentation by Bruce Crain and Greg Abernathy of LMAS titled “Aircraft-Lightning Protection,” which discussed aircraft lightning protection using the C-130J FAA lightning protection certification program as an example. The presentation was followed by a tour of the C-130J and F-22 production areas. Visitors were then treated to a tour of the LMAS Electromagnetics lab for demonstrations of lightning testing.

[Congratulations to Bruce Crain and his wife on their newest addition to the family born April 8th. Bruce is now the proud father of four boys!]

John Clarke reports that the February meeting of the Central New England Chapter featured Ismat Sheikh-Yassin, of Technology International in Richmond,Virginia. The topic of his presentation was “Gaining EMC and Safety Compliance for the Semiconductor Industry.” The semiconductor industry is rapidly expanding. Its growth is having a major impact on the world economy according to the SIA (Semiconductor Industry Association). This growth results in an increase in compliance costs. The presentation addressed regulatory concerns by providing an overview of the guidance document Semi S2-93A and the EU’s CE marking directives.

The topic of the March meeting was “The Technical Construction File.” The speaker was Robert Martin of Intertek Testing Services in Boxboro, Massachusetts. In the European Union (EU), a Technical Construction File (TCF) can be used to show compliance with the EMC Directive. The EMC Directive alone uses TCFs as described in Section 10.2 of the directive. The presentation described the uses of a TCF and the preparation details. The relationship between TCFs and technical files, and requirements for approvals, were also discussed.

Photo by Dick Ford

Long time Chicago Chapter Chairman Don Sweeney (R) was presented with a commemorative plaque to recognize his years of service to the chapter. Dale Svetanoff (L) is shown doing the honors.

The Chicago Chapter of the EMC Society met on Wednesday evening, April 1, to host Dick Ford, recently “retired” from NRL, as special Guest Speaker, and to install the 1998 slate of officers.

Dick treated those in attendance to his very interesting discussion about the NAVAIR EMC Excellence Program, and the impact it has had on the EMC industry for most of the past decade.

Long-time Chair of the Chicago Chapter, Don Sweeney (of D.L.S. Electronic Systems), has retired from the position and was awarded a plaque in honor of his decades of service, leadership, and dedication. (The EMC Society Official Photographer, Dick Ford, “just happened” to have his camera available to capture the moment.) The new Chicago Chapter Chair is Derek Walton (Barber-Coleman), who was an active participant on the 1994 IEEE EMC Symposium Committee in Chicago.

All Chicago Chapter members wish Don and Derek well in the exciting times ahead. Other Chicago Chapter officers are: Roger Swanburg, Vice-Chair; Raymond Klouda, Secretary; Bill Bumbliss, Treasurer, Jack Black, Membership; Tom Braxton and Dale Svetanoff, Programs.

The Israeli IEEE EMC Chapter held a meeting on March 11, 1998. This meeting – a full day workshop on EMI in Radio Communication Systems and Networks, was held jointly with the Israel IEEE Communications Chapter, and was sponsored by the Holon Center for Engineering Education, in Holon, Israel.

Participation in the meeting was great! Over 75 attendees. After a short welcome by the EMC and Communication Chapter Chairmen, Elya B. Joffe and Dr. Adam Livne, a welcome address on behalf of the Holon Center for Engineering Eduacation was given by Prof. Jacob Gavan, Head of the Communication and Propagation Department. Dr. Gavan also started the first undergraduate EMC course in any academic institute in Israel at the Holon Center.

Following the welcome address, the following technical presentations were given: “RFI Skirt in Cellular Systems” by Mr. David Peso of Telrad; “Interference in Cellular Systems” by Dr. Dan Shklarskey of Cellcom; “Propagation Interference in Mobile Satellite Communications” by Dr. Zvi Muninner of the Asher Space Research Agency, the Technion; “Propagation and Interference in a Universal Cell, from Mega Cells to Cento-Cells” by Prof. Jacob Gavan of the Holon Center for Technological Education; “EMC and a Frequency Spectrum Management and Analysis System” by Lt. Col. Moshe Ravfogel of the Israel Defence Forces; “Co-existence between Transmitting Services and Passive Services” by Mr. Peleg Lapid; “The Development and Future of the National Communication Services in Israel” by Mr. Moshe Galili of the Ministry of Communications; “A Comparison of the Coupling between Antennas Installed on a Common Mast in Various Configurations” by Mr. Elya B. Joffe of K.T.M. Project Engineering; and “High Definition TV (HDTV)” by Dr. Ezra Nuriel of Nitrino.

The Oregon and SW Washington Chapter has continued to be active this past winter. Attendance at monthly meetings has been consistently between 30 and 35 people. And, more attendees have been joining the IEEE and EMC Society.

In January, Mr. Daryl Gerke of Kimmel Gerke Associates, Ltd., gave a very informative presentation on printed circuit board design. Daryl did an excellent job giving practical examples to go along with basic EMC theory.

Photo by Henry Benitez

Speaker Bill Ritenour shown
making his point at the Oregon
Chapter meeting.

In February, Mr. Bill Ritenour of EMC Compliance, LLC gave his now famous presentation entitled “Truckers, Fat Ladies and EMI at the Gas Pump”. His talk was very illuminating and humorous. Despite the picketing outside, Bill gave a very informative talk. I guess the truckers did not like the advertised affiliation with EMI!!

At the March meeting, Mr. Scott Roleson of Hewlett-Packard in San Diego, gave a presentation on “Gaining Insight from EMI Radiation Patterns”. He gave several examples of how these patterns have helped to lead EMI teams to an understanding of the physical mechanisms that generate these patterns.

We have received very positive feedback from the membership on all the winter meetings. We will not have a meeting in April, but instead encourage attendance at the Seattle EMC ‘98 Workshop on April 28 featuring Henry Ott. The Oregon and SW Washington Chapter will host an EMC Colloquium in April 1999 as the Portland and Seattle EMC Chapters continue to alternate events.

The EMC Chapter has encouraged another inter-chapter Oregon Section Summer event for this year. This event will be the second annual summer section networking mixer and will be held on July 15th. The focus of the event is to facilitate interaction among all the varied chapter members in the Oregon & Southwest Washington Section.

Dave Bernardin reports that Mr. Robert Dockey of Hewlett Packard gave an excellent talk at the March meeting of the San Diego chapter. The presentation was titled: “New Techniques For Printed Circuit Board Common-Mode Radiation” Forty one people attended the meeting at TUV Product Services. The meal prior to the meeting was also a huge success, featuring home made lasagne with spaghetti and meat balls prepared and served by Barbara Bernardin. The meal was a terrific beginning for a well-received talk on some unconventional ideas for CM radiation from circuit boards. The question and answer session after the talk was very interesting and brought out even more enthusiasm from a very interested group of EMC-oriented participants.

Photo by Janet O’Neil

Scott Roleson of Hewlett-Packard
(L) spoke at the Seattle Chapter’s
March meeting. He is shown with
the ever friendly Leo Smale (R) of
Kalmus in Bothell.

Photo by Janet O’Neil

Tom Lindgren (L) and John Kuras (R) of Boeing are busy
working on plans for the Seattle Chapter’s EMC ‘98
Tutorial with Henry Ott on April 28. Tom is the Seattle
Chapter Treasurer who did double duty on the event by
handling registration and finances. John is the Chapter
Secretary who promoted the event through the Chapter’s
Newsletter and Web Page. Jeannie Olson of Kalmus (C)
handled the exhibits and facilitated operations.

In January, the Seattle Chapter invited Daryl Gerke of Kimmel Gerke Associates to speak on the topic “How to Design to Fail FCC and CE Tests in 20 Easy Steps.” Although presented in a humorous way, Daryl’s presentation illustrated a number of EMI problems that often occur at the design stage. Topics included “Avoid Ferrites Like the Plague” and “You Can Never Have Too Many Pigtails”. Over 40 people from the growing EMC community in Seattle attended the meeting.

Mr. Bill Ritenour of EMC Compliance, LLC. spoke at the February Chapter meeting on the now legendary topic “Truckers, Fat Ladies, and EMI at the Gas Pump”. This presentation was definitely non-politically correct, but very humorous. Through cartoons of Herman, “the Spark Gap” kid (i.e. a greatly put upon gas pump), the effects of EMI in a present day filling station on any given day were discussed. The problems ranged from ESD due to a generously proportioned human sliding out of a car on a cold day, to RF interference from a 500 watt illegal CB mounted on a large commercial conveyance, and finally to an electrically “abrupt” large induction motor operating in an adjacent car wash. The chapter members appreciated this new slant on EMI and ESD.

In March, the ever popular Scott Roleson of the Hewlett-Packard Company in San Diego, spoke on the topic “Gaining Insight from EMI Radiation Patterns”. Mr. Roleson stated that when radiated EMI amplitude is plotted as a function of rotational angle, and when these patterns fall into recognizable shapes, specific antenna-like structures can be inferred as the source of this EMI in some cases. In this way, antenna-like azimuthal radiated emissions patterns can lend useful insight into EMI problems in computing and other electronic equipment. Mr. Roleson’s presentation described the methodologies for obtaining EMI radiation patterns and how they can be used to infer antenna structures. Examples were provided and the limitations of this technique were addressed. It was definitely an insightful presentation.

The Seattle Chapter is excited about the positive response to the Henry Ott one day tutorial and exhibition scheduled for April 28. Also, at the May Chapter meeting, Lee Hill of Silent Solutions EMC Consulting will speak on “Inductance, Ground Plane Gaps, and Radiated EMI in PC Boards.” Everyone is welcome to attend the Seattle Chapter meetings. To receive the Seattle Chapter Newsletter, contact John Kuras at 425-717-1363 or john.c.kuras@boeing.com

Photo by Janet O’Neil

Can you guess who provided the witch’s hat and clown
wig for Helene and Henry O’Neil? (Hint: The hat and wig
were gifts from the Seattle Chapter speaker who appeared
in costume on October 30. Thank you Mr. W!)

Photo by Janet O’Neil

After the February Seattle Chapter meeting, speaker Bill
Ritenour (R) enjoyed a spontaneous technical exercise with
chapter member, Dr. Howard Johnson (L), which lasted
until close to midnight.

At the Southeastern Michigan Chapter meeting, Kimball
Williams (R) enjoyed talking shop with speaker Dick Ford
(L) in the Eaton anechoic chamber.

Kimball Williams of Eaton (C) is shown with Professor
Donald Zinger (L) and Vincent McGinn (R) of the Northern
Illinois University Department of Electrical Engineering.
Mr. Williams, on behalf of the Southeastern Michigan
Chapter and the EMC Society Education Committee,
gave a presentation to students entitled “Introduction
to Electromagnetic Compatibility” in March. After the
presentation, Mr. Williams was pleased to award a check
for $5,000 to the University. This represents an EMC
Society grant for furthering EMC education.

Kimball Williams reports that on February 9, 1998 the Southeastern Michigan Chapter featured John D. M. Osburn, of EMC Test Systems in Austin, Texas. John discussed “The State-of-the-Art of Reverberation Chamber Testing.” The meeting took place at Eaton Corporation in Southfield, Michigan. Snacks and refreshments were provided. Reverberation chamber testing technology is a radical departure from traditional EMC testing approaches. As with any test approach, there are advantages and disadvantages. John began with his own definition of a reverberation chamber, then proceeded to the theory of a reverberant enclosure to show how reverberation chambers work. John then reviewed reverberation chamber test applications as they currently appear in domestic and international standards. He also discussed reverberant operation performance validation requirements for domestic and international specifications, and described the conduct of reverberation chamber testing, specifically taking into account the special characteristics of reverberation chambers. He also discussed potential pitfalls of reverberation chamber testing.

John closed with a prediction of the future of reverberation chamber testing and a question and answer period. Twenty seven EMC engineers and technicians were present for John’s presentation, and the discussion after the talk lasted forty five minutes with many probing and introspective questions.

The Southern Maryland Chapter conducted their first technical and organizational meeting for the year on April 7, 1998 at the Fort George G. Meade Officer’s Club in Fort Meade. During the meeting, Mr. Ted Harwood, the Chapter Chairman, announced that the Chapter will continue to meet at the same location every other month, with technical meetings now scheduled for June 2, September 1, and November 3, 1998. The annual election of officers will be held during the September meeting. Other organizational reports came from Mr. Virgilio P. Arafiles, Vice Chairman, Mr. Charles Gaston, Secretary, and Mr. Fred Kirby, Treasurer. Mr. Arafiles reported that the EMC Society has been actively supporting the IEEE Baltimore Section effort to provide robot kits to area high schools for the purpose of generating interest in science and electrical engineering. Mr. Gaston provided reports on the past year’s chapter meeting attendance, and Mr. Kirby completed the organizational meeting with his 1997 financial report.

Mr. Jerry Hodges, Technical Director of the Joint Spectrum Center, Annapolis, MD, was the featured guest speaker. He discussed changes at the Joint Spectrum Center (formerly the Electromagnetic Compatibility Analysis Center or ECAC) which were brought about by the recent FCC Spectrum Auction. He also talked about the impact of the auction on the Department of Defense (DoD) and the JSC Executive Agency move from the US Air Force to the Defense Information Agency (DISA). Mr. Hodges intimated that the well-publicized spectrum auction will end up costing taxpayers and the DoD billions of dollars. For example, the 1997 auction of 75 MHz could cost between $1B to $5B as the DoD modifies both developmental and existing weapon systems to operate outside the frequencies being sold to commercial bidders. He also mentioned that commercial encroachment on current US government frequency assignments could result in widespread safety and operational disruptions. For example, an INMARSAT proposal to re-allocate one of the GPS frequencies could cause severe, costly disruptions on global users of the DoD-developed global positioning system. Finally, Mr. Hodges mentioned that the cost and operational impact of the spectrum auctions have created concerns up to the ASD/C3I and Joint Chief of Staff level, prompting the immediate move of the JSC executive agency from the Air Force to DISA.

Photo by Dick Ford

Speaker Kenn Atkinson (L) is congratulated on a
successful presentation by Washington DC/Northern
Virginia Chapter Chairman Larry Cohen (R).

Recently retired after thirty years with the US Navy, long time EMCS Board of Director member, Dick Ford, nce & Independent Consultant, was invited to speak at the Minneapolis, Chicago and Detroit EMC Chapter meetings held on three consecutive nights March 31st, April 1st and 2nd. His topic at all three meetings was the Navy’s NAVAIR Model Program for EMC Excellence.

During the 1970s and 80s, the Navy was plagued with a host of electromagnetic incompatibility problems. In response, the Navy implemented a number of initiatives to redress these problems. Between 1973 and 1985, each of the three major Navy systems commands, NAVSEA, NAVAIR and SPAWAR each established their own corrective action programs. Though each program was more or less successful in identifying and correcting EMI deficiencies, EMI problems kept occurring. By 1989, many felt that corrective action programs were just not enough. The Navy had to get out of the fix- it mode and get into a preventative mode. To address this challenge, the Chief of Naval Operations requested the Naval Air Systems Command lead a task force to brainstorm the problem, define a possible successful program, and then establish a model Navy Program for EMC Excellence (NPfE) within the air community.

Photo by Dan Hoolihan

(L to R) Bill Mack, Rosemary Hoolihan, Curt and Colleen
Sponberg, Professor Jose Perini, and Sue Mack are shown
celebrating St. Patrick’s Day on March 17 at Champp’s
restaurant in St. Paul, Minnesota. Professor Perini had the
luck of the Irish with him (and a “small” beer) during his
visit to the Twin Cities Chapter.

Dan Hoolihan (L) presents the nostalgic Amador t-shirt to
speaker Dick Ford (R) after his presentation to the Twin
Cities Chapter. Mr. Hoolihan was a co-founder of Amador
Corporation which was later acquired by TUV Product Service.

In his presentation, Dick described the evolution of NPfE over the past nine years. He described the two major parts of the program, NARTE certification of EMC engineers and technicians, and the National Institute of Standards and Technology’s (NIST) National Voluntary Laboratory Accreditation Program (NVLAP) and then gave his views of how NPfE fits in with the challenges posed today by DOD downsizing, Non Development Item (NDI) & Commercial Off The Shelf (COTS) procurement processes, DOD use of commercial specs and increased emphasis on NATO (and hence) EMC standardization. Dick was a central participant in the original task force and played an active role in defining the particulars of the program.

Next year will be the tenth anniversary of the NAVAIR model program. NAVAIR has recently announced its continued commitment to the program and has reinvigorated it support to NIST/NVLAP. Dick is supporting NAVAIR’s Anthony Iacono, EMC Team Leader for the NAVAL Air System’s Command, in this effort.

Asked how the presentations were received, Dick replied that they went great, but noted that of the six airplane legs to travel to/from the various locations, three times the planes were cancelled and/or had significant delays making an otherwise tight schedule much more than exciting.

Kenn Atkinson of Atkinson Engineering presented “Demystifying Measurement Uncertainty” at the 19 February luncheon meeting of the Washington DC/Northern VA Chapter. The presentation included an overview of measurement uncertainty requirements for EMC measurements as well as a quick review of the calculations and statistics used to determine measurement uncertainty. He then discussed the practical application of uncertainty for EMC labs and presented a simplified approach for calculating the total expanded uncertainty needed for measurement reports. Mr. Atkinson also displayed examples of EMC measurement uncertainty using the “AEsoft Uncertainty Software” which calculates the uncertainty from the measurement equation and applies the resulting uncertainty values to measurement data.

TODD HUBING
ASSOCIATE EDITOR

Chapter Chatter

Speaker Bill Ritenour shown
making his point at the Oregon
Chapter meeting.

TODD HUBING ASSOCIATE EDITOR

Chapter Chatter

Speaker Bill Ritenour shown making his point at the Oregon Chapter meeting.

TODD HUBING
ASSOCIATE EDITOR

Speaker Bill Ritenour shown
making his point at the Oregon
Chapter meeting.