By Lars Jacob Foged The development of 5G cellular networks is well underway and requires a new approach to ensure accurate measurement of the antenna components. With flexible radiation patterns which are capable of adapting to the changing situations in mobile networks, the full characterisation of the Active Antenna System (AAS) in 3D space has been the focus of … [Read more...]
System Compatibility: An Essential Ingredient for Achieving Electromagnetic Compatibility and Power Quality for Lighting Control Systems
Philip Keebler, Kermit Phipps, Frank Sharp, EPRI Lighting Laboratory For years, lighting systems have been operating as stand-alone loads without the use of sophisticated lighting controls for energy savings in all types of facilities—residential, commercial, and industrial. Utilities and end users viewed lighting controls in the past as, luxury, systems that were used only … [Read more...]
Differential Transfer Impedance of Shielded Twisted Pairs
Michel Mardiguian, EMC Consultant, Saint-Rémy-lès-Chevreuse, France The concept of Shield Transfer Impedance (Zt), introduced by S. Schelkunoff in 1934, is a very convenient parameter for the prediction and control of EMI coupling through cable shields. Although widely applied to coaxial cables against EMI susceptibility problems, the Zt parameter can be easily extended to … [Read more...]
Understanding the Changes to FCC 5 GHz Part 15.407 Regulations
David A. Case, Cisco Systems, Richfield, OH In July of 2003, the International Telecommunications Union – Radio adopted Recommendation 229, allocating the 5150-5350 MHz and 5470-5725 MHz bands to mobile service, including RLAN systems.* The following year the FCC updated its Part 15.407 regulations to include the 5470-5725 MHz band, as well as require changes for devices that … [Read more...]
How Smaller Form Factors Exacerbate ESD Risks and How Foil Resistors Can Help
Yuval Hernik, Vishay Precision Group, Malvern, PA For most of us, electrostatic discharge (ESD) and static electricity are little more than the shocks received when touching a metal doorknob after walking along a carpeted floor, or when opening a car door. The level of the voltage produced depends on a number of factors, such as the affinity of the two bodies and the air … [Read more...]
Clocking Strategies for EMI Reduction
Sassan Tabatabaei, SiTime Corporation Electronic devices have to operate in close proximity, whether it is in the home, office, industrial establishment, or outdoors. Each of the devices may radiate electromagnetic energy, which can interfere with the operation of the rest of the devices. To avoid such harmful interference, governments and industry bodies limit the amount of … [Read more...]
USB Interface on Laboratory Surge Generators
Jeffrey D. Lind, Compliance West USA As any laboratory engineer knows, harsh, noisy lab environments often result in data loss and/or resets of test equipment or host computers. A potential solution to this challenge is the successful implementation of mains power distribution in the lab, and an isolated serial/USB design for laboratory computer systems. This will allow the … [Read more...]
EMC Performance of a Product Over Its Lifetime
Gert Gremmen, Tim Haynes, Ralph McDiarmid, Ed Price, John Woodgate EMC performance of a product is likely to vary with age as the physical characteristics change, e.g. caps dry out and metal junctions oxidize, etc. Obviously, the product is designed with the intention of consistent compliance over the life of the product, but are there any requirements or guidance relating to … [Read more...]
Effective EMC Troubleshooting with Handheld Probes
EMC testing is an unavoidable part of the development cycle for electronic products. As clock frequencies continue to increase, radiated emissions get harder to control. In an ideal world, the R&D engineer would test the emissions from his product early in the design stage and retest frequently as design changes were made, just ass he tests whether his product meets its … [Read more...]
1.04m Rod, Antenna Factor and Received Level in MIL-STD 462/461E Compared to MIL-STD 461F Test Set Up
David A. Weston, EMC Consulting, Inc., Merrickville, Ontario, Canada INTRODUCTION This paper shows that the antenna factor of the receiving rod antenna and the E field incident on it, from a standard source of radiation, both change when the counterpoise of the rod is either isolated from the ground plane on the table (new MIL-STD-461F set up), or connected, as per … [Read more...]
