emi

Sooner or later, anyone involved with EMI will be involved in troubleshooting an EMI problem, wherever it may surface. Most commonly, the problems will be uncovered during EMI testing, generally very late in the product design cycle, resulting in costly patches and schedule delays. It is best if preliminary EMI testing is done early in the design stage - EMI problems can be uncovered early enough that corrective action can be done in a timely fashion, ideally at the circuit board level. On the back end, EMI problems are often encountered in the field - perhaps because the environment is harsher than that expected by the regulatory agencies or because of an installation problem.

The equipment should have passed the emissions scan. It should not be susceptible to this noise. The filter analysis said this was not a problem. The case should be an excellent shield. Why doesn’t this pass?

There are two statements I have heard about electromagnetic interference which are both related and true: EMC is the science and engineering of things that are typically not on the schematic [1], and EMI is often caused by issues of geometry [2]. The first statement speaks to the issues of parasitics, or cross coupling of energy due to magnetic induction or capacitance. The second says that the parasitics can be controlled or reduced if the proper routings and separations are maintained, and that once a degree of understanding about these coupling mechanisms is understood the control of them can be obtained.

A team of archaeologists found an ancient Roman gladiator school in Austria using remote-sensing techniques over the last several years.  The buried remains cover over 2,800 square meters and includes cell blocks, a training arena and a bath complex.

Toyota is currently testing a new wireless charging system for plug-in hybrids and electric cars in three homes in Japan. The system is comprised of a unique electromagnetic coil set that is in the ground and uses inductive battery charging methods that could eliminate the use of wires and plugs.

"A rose by any other name would stink." – Kenneth Adamson

We have all seen advertising copy for test equipment manufacturers’ “EMC receivers” and “EMC test services” provided by commercial EMI test facilities. While we know what the aforementioned receiver does, and what sort of services the test facility supplies, the nomenclature is wrong and is symptomatic of a deeper problem.

“If you are not willing to learn, no one can help you.
If you are determined to learn, no one can stop you”. – Author Unknown

In today’s fast-paced product development cycles, the pressure to compress testing and certification schedules is constantly increasing, with global competitors all rushing to get their new technology to market first. Mistakes made in compliance testing and certification processes can have huge financial impacts if product releases are delayed, or lead to later stop-ships or recalls. Utilizing project management techniques can provide great benefits by improving the efficiency and quality of compliance projects.

FFT-based EMI test receivers can be used for EMI compliance measurements in accordance with Amendment 1 to 3rd Edition of CISPR 16-1-1 if this standard is referenced in the product standard. The use is motivated by reducing the scan time by several orders of magnitude and to get more insight due to the possibility of applying longer measurement times and enhanced measurement functions like spectrum in persistence mode. For precise and reproducible measurements the use of preselection filters is highly recommended.

In this article, we present the analysis of electromagnetic interference (EMI) shielding effects of wireless power transfer (WPT) using magnetic resonance coupling for board-to-board level interconnection. Board-to-board WPT consists of source coil, receiver coil, and load which are manufactured on printed circuit board (PCB).