INTRODUCTION Modern electronics demand low EMI and EMC conformance, both of which are related to component selection and physical layout in the power supply section of a device. Many more designs are demanding higher power levels alongside high power efficiency, as well as low-noise power supplied to mixed-signal systems. As a result, EMI and EMC challenges are more apparent … [Read more...]
How to Cut Costs and Improve Lead-times in Circuit Board Shields: Standard EMI Solutions for Custom Designs
Dario Negrini Leader Tech Inc. Tampa, FL Let's face it. If you didn’t have to worry about EMI shielding issues with your circuit board, life would be much simpler. Unfortunately, as product designs continue to shrink in size and as the list of features continues to grow, EMI compliance issues cannot be overlooked. Circuit board shields are one of the best ways to … [Read more...]
2006 Update on Intentional Electromagnetic Interference (EMI)
Dr. William A. Radasky, Ph.D., P.E. Metatech Corporation Introduction Over the past 6 years a substantial number of articles have been written by this author and others identifying the threat and importance of intentional electromagnetic interference (IEMI) [1-5]. Since the publication of the Interference Technology Annual EMC Guide in 2005, work has continued at an … [Read more...]
Concerning Exposure of Workers and the General Public to Electromagnetic Fields
Keith G. Richens Cranage EMC & Safety Oakley, Shropshire, UK Introduction Electromagnetic fields (EMF) are universally present in the everyday environment, including workplaces and public areas. Measurements are made to identify and characterise them to ensure that people are not exposed to fields that could potentially cause injury or adversely affect … [Read more...]
Optimized Lightning Protection for Higher Frequencies
George M. Kauffman, P.E. Frequencies above 4.5 GHz are being used in greater number for a wide range of outdoor communications. These uses include critical infrastructure applications where long lifetime and high availability requirements are paramount. In outdoor antenna applications, the exposure to lightning effects must be considered in most locations. When cables … [Read more...]
Reducing High Frequency Ground Currents to Zero
Patented system solution provides a more effective grounding method. Mark Panko Zero Ground LCC, Waukegan, IL, USA Technology and the electrical/electronics industry have changed at a dizzying pace. Among these many changes is the growing use of motors with adjustable speed drives (ASDs) or variable frequency drives (VFDs). An unforeseen consequence of using these efficient … [Read more...]
The FCC Dynamic Frequency Selection Test Procedure
David A. Case NCE, NCT On February 3rd 2006, after three years of work the US ITAC-R group addressing the development of the proposed US DFS test procedure to be used to certify products under FCC Part 15 was completed. This test procedure is milestone in verifying the sharing of the 5GHz band with Radiolocation systems. The work group consisted of Industry experts as well as … [Read more...]
Measuring and Managing Electromagnetic Interference: Selecting the Right Antenna for Your E3 Program
Philip F. Keebler and Kermit O. Phipps EPRI Solutions, Knoxville, TN Bradford R. Connatser WriteNow Communication, Knoxville, TN Introduction What is an E3 program? Outside of the military environment, the National Aeronautical Space Administration (NASA), and the telecommunication industry, the study of electromagnetic environmental effects (E3) and spectral management … [Read more...]
Selecting a Radiated Emissions Test Site
Bob DeLisi Principle Engineer – EMC Underwriters laboratories Inc. Michael Windler Operations Manager NA EMC Underwriters laboratories Inc. Introduction Electromagnetic compatibility (EMC) testing and certification has become an integral part of product regulatory compliance. With the growing number of wireless communications devices being introduced into the RF … [Read more...]
Using A Transmission Line Model To Analyze Shield Current Distribution Resulting From Bulk Current Injection (BCI)
Arthur J. Glazar, Life Senior Member IEEE Background Radio frequency (RF) signal energy is normally confined to the interior of a coaxial cable. RF currents on the surface of a cable shield are undesirable and generally indicate a problem. Shield surface currents can occur as the result of conducted susceptibility (CS) or radiated susceptibility (RS). Whatever their … [Read more...]
