Back by popular demand, the Hardware Experiments and Computer Modeling and Simulation Demonstrations session of the 2011 IEEE International Symposium on EMC in Long Beach offered attendees an exciting array of topics and an alternative to classroom-style lectures. For 19 years running, the Experiments and Demonstrations session has provided an interactive forum for discussing electromagnetic phenomena, as presenters perform live experiments or demonstrate how computer software can solve a particular EMC-related problem. Attendees are able to have discussions with the presenters and often come away with a deeper understanding of the fundamental theory underlying the experiment or demonstration.
     This year’s session was organized by teammates Sam Connor and Bob Scully. Sam and Bob were able to recruit presenters for nine hardware experiments and 10 computer software demonstrations. Four of the hardware experiments were selected and presented by Chris Semanson, a former student of Mark Steffka at the University of Michigan at Dearborn. Chris chose his experiments from the EMC Education Manual, originally written and compiled by Henry Ott and Clayton Paul. Chris deserves a special tip of the hat for building and presenting these four experiments, which drew excellent crowds and lively discussions!
     The Experiments and Demonstrations booths were nestled deep in the back of the exhibit hall, but those who made their way back there were well-rewarded with four concurrent presentations from which to choose. While in the area, attendees could also check out a new attraction: a Video Demonstrations booth which showed a loop of recorded experiments that demonstrated extreme electromagnetic phenomena such as Tesla coils, rail guns, and levitation.

PHOTOS BY KEN WYATT
Dr. Arturo Mediano of the University of Zaragoza, Spain demonstrated the usefulness of near-field probes in finding EMI problems and in tuning circuits. His collection of probes was quite impressive!	Ever wonder why your conductive plastic enclosure fails radiated EMI testing miserably? William Kimmel of Kimmel Gerke Associates, Ltd. showed how well various seam closure techniques work.
Garth D’Abreu (standing left) of ETS-Lindgren and Dennis Lewis (standing right) of Boeing showed the fundamentals concepts and benefits of reverberation chamber testing.	Modeling of large, complex systems requires hybrid, optimized techniques such as MoM/MTL. Dr. Roman Jobava from EMCoS Ltd. traveled from Tbilisi, Georgia to explain how this approach can solve large EM problems.
Gopinath Gampala of EM Software & Systems (FEKO) presented “Simulation of Complex EMC Problems Involving Cables Using Combined Field and Transmission Line Approach.” This was particularly helpful for automotive and aircraft applications.	Chris Semanson (far left) of the University of Michigan – Dearborn presented four demonstrations at the Long Beach Symposium. EMC experts Lee Hill of SILENT (far right) and Tom Van Doren of the Missouri University of Science and Technology (second from right) stopped by to see Chris’s handiwork.
Harihara Subramanian (right) of ON Semiconductor in Bangalore, India demonstrated the benefits of the use of spread-spectrum clocking and noise cancelling signals to improve EMI performance of a product.	Dipanjan Gope (far right) of Nimbic showed how one can model a complex system package on a PCB in his demonstration “Real World EMI Correlation Challenges and Techniques.”
Chris Semanson of the University of Michigan – Dearborn described his work in developing experiments that complement Henry Ott’s book, Electromagnetic Compatibility Engineering, in his article “Creating Practical Experiments on EMC” from the Summer 2010 issue of the EMC Newsletter. He attended the Long Beach Symposium to personally show several experiments.	Brendon Berg of Advanced Test Equipment Rentals was a tremendous help to the Experiments and Demonstrations Committee for EMC 2011. They loaned equipment and made all the arrangements to have it on site and on time for the Symposium. Kudos for a job well done!

     The Experiments and Demonstrations presentations made as part of this year’s symposium included:

• Circuit Techniques to Reduce EMI in an Electronic System. Using a test board, spectrum analyzer and near-field probes, Harihara Subramanian of ON Semiconductor demonstrated the benefits of the use of spread-spectrum clocking and noise cancelling signals as a means to aid in the improvement of EMI performance of a product.
  
• Seam Leakage in Coated Plastic Enclosures. Ever wonder why your conductive plastic enclosure fails radiated EMI testing miserably? William Kimmel of Kimmel Gerke Associates, Ltd. showed how well various seam closure techniques work.
  
• Improving EMC Test Productivity with Automated EMC Test Software. Joe Tannehill, EMC Software Engineer, ETS-Lindgren, Cedar Park, Texas showed how to improve the productivity of EMC testing with automation software, which helps increase the throughput of a lab and lowers cost.
  
• Effective 3D Full-Wave Simulations. How can I tell if this will work before I build it? A set of live demonstrations by Alex Razmadze of the Missouri Institute of Science and Technology showed how full-wave simulations can be used to study real-world problems.
  
• Noise Measurement by Induction. This classic experiment demonstrated how a square loop probe can be used to trace noise signals in a circuit back to their source. Chris Semanson brought this experiment straight from the labs of the University of Michigan Dearborn to Long Beach and deftly explained the principle of induction involved.
  
• Efficient Testing Using a Reverberation Chamber – with “Real Time” Examples. This crowd-pleaser featured a working reverberation chamber with a transparent wall so attendees could “see” the impact of the fields during testing. Dennis Lewis from Boeing and Garth D’Abreu from ETS-Lindgren teamed up to cover the fundamentals concepts and benefits of reverberation chamber testing.
  
• Hybrid MoM/MTL Approaches for the Calculation of EMC Problems of Complex Systems. Modeling of large, complex systems, such as aircraft and naval vessels, requires hybrid, optimized techniques like MoM/MTL. Dr. Roman Jobava from EMCoS Ltd. traveled from Tbilisi, Georgia to explain how this approach can solve large EM problems.
  
• Modeling the Coupling to Cables in a 3D Environment. Paul Duxbury of CST UK was on hand to show attendees how to study EMI susceptibility problems with cable bundles and harnesses, where the dimensions of the cable cross-section are much smaller than the length of the cables and the dimensions of the shielding enclosure.
  
• The Thinking Engineer’s Voltage Measurement. The second classic experiment presented by Chris Semanson illustrated cleanly and simply how the placement of probes in an electronic circuit can affect the results of the measurement.
  
• Effectiveness of Shielding Materials and Impact of Slots and Bonding of Shields on PCB Radiation and Immunity. The shielding performance of enclosures is always a popular topic at the symposium, and Professor Bogdan Adamczyk, Grand Valley State University, Grand Rapids, MI joined Jim Teune, Lead EMC Engineer, Gentex Corporation, Zeeland, MI to explore the shielding performance of various materials and slot geometries.
  
• Modeling and Simulation for Cosite EMI Analysis. Predicting cosite interference in complex RF environments with multiple emitters and receivers is a challenging problem for system designers, which requires numerical simulation tools. Fred German, Delcross Technologies, Champaign, IL, demonstrated the process of combining models to predict EMI margin and how the quality of the component models can impact the results.
  
• 2D Cross-Sectional Analysis in Signal Integrity. When studying the signal integrity of a data link, accurate transmission line models are a key component, and this relies on a 2D cross-sectional analysis engine. Alex Razmadze of the Missouri Institute of Science and Technology explained how this 2D cross-sectional analysis works, and demonstrated how the inductance and capacitance matrices can offer important insight into coupling mechanisms and crosstalk.
  
• The Effect of Circuit Impedance on Field-Coupled Crosstalk. Chris Semanson’s third experiment highlighted a phenomenon which is a powerful debugging tool: the termination impedance of a circuit determines which coupling mechanism (electric field or magnetic field) dominates. With the well-designed test circuit from the EMC Education Manual, the effect was shown very clearly.
  
• Near Field Probes in EMI/EMC/RF Design and Troubleshooting. Dr. Arturo Mediano of the University of Zaragoza, Spain demonstrated the usefulness of near-field probes in finding EMI problems and in tuning circuits. His collection of probes was quite impressive.
  
• Simulation of Complex EMC Problems Involving Cables Using Combined Field and Transmission Line Approach. The problems posed by cables affect so many of us that this topic drew a second demonstration. Gopinath Gampala and C.J. Reddy of EM Software & Systems demonstrated a MoM/MTL approach to solving these cable problems.
  
• EMC Issues on Printed Circuit Boards. Since we know that unintended current return paths cause many of the EMI noise issues on printed circuit boards, software can be developed to check circuit board designs for problems in return paths. When problems are found, they can either be corrected or modeled if further study is needed. Matthias Troescher of CST AG, Munich, Germany presented this design methodology, from design rule checking to full-wave modeling of the violations.
  
• Ground Noise in Digital Logic. What effect do self-inductance and mutual inductance have on a digital circuit? This experiment from the Education Manual explored these questions as Chris Semanson took attendees through his fourth experiment exploring the various permutations.
  
• Real World EMI Correlation Challenges and Techniques. Dipanjan Gope of Nimbic, Bellevue, Washington showed attendees how one can model a complex system package on a PCB. The use of optimized techniques and parallel processing in a cloud environment were both discussed.
  
• Full-wave EM Simulation of High-Speed PCB/Package Designs. Darryl Kostka of CST, San Mateo, California presented on the topic of an integrated design, analysis and simulation workflow for high-speed IC/Package/PCB development. Examples were shown and important considerations such as boundary conditions and package truncation were discussed.
  

     By all measures, the Experiments and Demonstrations were a valuable and exciting portion of the technical program, thanks to the contributions of all of the presenters. Be sure to stop by the Experiments and Demonstrations booths next year in Pittsburgh at the 2012 IEEE International Symposium on EMC, or better yet, propose an experiment yourself.               EMC