Min Zhang

This Column discusses a technique for troubleshooting radiated immunity failures in electronic devices using near-field probes. It presents a case study, explains the method's application, and addresses its limitations and safety considerations for bench-level testing.

This series of articles delves into the design principles of power filters for switched-mode power converters and similar applications, focusing on conducted and radiated emissions. Part 1 provides an overview of filter design principles, emphasizing the need for specialized approaches to meet EMC specifications in an increasingly electrified and sustainable world.

This article discusses using the reciprocity theorem in EMC troubleshooting, particularly for immunity issues. It describes a case study involving a smart meter and demonstrates how emission measurements can help identify susceptibility problems, highlighting the usefulness of walkie-talkies in testing.

In large systems, such as big cabinets housing numerous electronic components, employing the near-field probe method can be time-consuming and, depending on the voltage level, potentially unsafe (for instance, when dealing with high-voltage circuits requiring isolation). In such scenarios, an alternative approach is necessary.

Solving EMI problems isn’t only about ensuring that a product can meet EMC regulations and standards (although it’s a significant part of the job). Another crucial reason for addressing EMI issues is to enhance product reliability, especially when a product operates in public or industrial areas where there are many different types of noise sources.

Conducted emission tests can provide reasonably accurate results and also serve as a reliable indicator of radiated emissions, as some of these emissions propagate through cable wiring.

This article offers some useful insights and guidelines on how to effectively design and test systems using wide band gap devices to optimize product performance and achieve EMC compliance.

During conducted emission tests, one of the challenges manufacturers face is the resonance peaks in the harmonic noise somewhere between 10 MHz and 30 MHz. Often, no amount of filtering will eradicate or attenuate the peak.

When it comes to in-situ radiated emission measurements, the combination of near- and far-field measurements is often the best approach.

In this column, we discuss several important features of a spectrum analyzer not covered in previous articles that are worth your consideration.