emi

"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).

This year marks not only the title anniversary, but arguably also that of the beginning of the modern era in vehicle electromagnetic interference (EMI) testing. Radiated emission (RE) testing of equipment to be used on self-contained vehicles is performed at one meter or less versus testing at a distance of three meters or more for equipment designed for use in homes, offices and factories.

Every EMI (electromagnetic interference) problem ultimately starts or ends at an electronic circuit. And since electronic components are the building blocks of circuits, it only makes sense to pay attention to the EMI impact of those individual components.

Probably the most important thing to remember about electronic components is that nothing is ideal. Components change values with frequency, current, voltage, and even physical size. And those changes may be nonlinear, adding a new level of complexity. Like a pilot, you need to know the limits so you stay within the envelope of safe performance.

In this article, a time-domain EMI measurement system for the frequency range from 10 Hz to 40 GHz is presented. Signals with a frequency of up to 1.1 GHz are sampled by an ultra-fast floating-point analog-to-digital-converter (ADC) and processed in real-time on a field-programmable-gatearray (FPGA). An ultra-broadband multi-stage down-converter allows for the measurement of signals with frequencies up to 40 GHz. Measurement times can be reduced by several orders of magnitude compared to traditional EMI-receivers that work in frequency-domain.