Min Zhang

Most EMI filter manufacturers validate performance in a clean 50-ohm environment, but real converters rarely operate that way. See what happens to insertion loss when source and load impedance reflect actual operating conditions, and why the gap matters.

Full-wave EMC simulation tools are powerful — but often too slow, too costly, and too complex for real-world troubleshooting. Dr. Min Zhang makes the case for free SPICE-based tools, walking through three field scenarios where quick models helped isolate failures, validate test setups, and guide next-generation designs.

A routine radiated emissions case took an unexpected turn when slow I/O lines started radiating 100 MHz harmonics—pointing to a deeper power distribution network problem. Dr. Min Zhang traces the root cause and the PDN fixes that made the ferrite beads unnecessary.

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 2 will examine specific aspects of switched power converters.

Got a noisy power system? This real-world EMI investigation reveals how seemingly minor grounding issues between compartments can create major interference problems - and shows how smart measurement techniques led to an elegant fix.

Near‑field probe techniques commonly used for EFT troubleshooting can also uncover radiated immunity failures. Using a real‑world audio device case study, this article shows how a simple benchtop setup exposed PCB‑level resonance, guided a low‑cost fix, and helped resolve chamber test failures.

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.

When traditional EMC troubleshooting tools fall short, the reciprocity theorem can reveal hidden immunity problems. This real‑world case study shows how unexpected RF sources—like walkie‑talkies—can expose susceptibility paths, helping engineers diagnose failures and strengthen designs with simple, effective fixes.

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.

Ever wonder why equipment mysteriously fails in the field? This case study reveals how one manufacturer solved frustrating intermittent timer resets in an industrial kitchen—using clever EMI troubleshooting techniques with an EFT generator and near-field probe. Learn their practical fix that ended costly service calls.