emc concepts explained

This article uses a classical circuit-theory model of a series RLC circuit to explain the phenomenon of ringing on a transmission line, or a PCB trace.

This article explains the creation of a bounce diagram for a transmission line circuit (see [1] for transmission line reflections).

This s-parameters tutorial consists of two parts: Part I discusses the fundamental background needed to understand the concept of s-parameters; Part II explains the s-parameters use in EMC measurements and testing

This article examines the spread-spectrum frequency dithering technique to reduce the EMI noise from a SMPS.

This column explores the conducted immunity test known as a Bulk Current Injection (BCI) test, according to ISO 11452-4 specification.

This article discusses a practical approach to designing an input filter to the switch-mode power supply (SMPS).

We compare the shielding effectiveness of various solid metallic shields by direct H-field measurements in the near field of the source.

Trace length does more to a capacitor's frequency response than most engineers assume. This study puts three connecting trace lengths through simulation and measurement, tracking how each shifts the self-resonant frequency and threatens decoupling performance at the frequencies that matter most.

Adding a guard trace between PCB traces sounds like a simple crosstalk fix — but grounding it wrong can actually make interference worse, not better. See how capacitive and inductive coupling respond differently to grounding placement, and why one counterintuitive result changes the design approach.

When two circuits share a return path with non-zero impedance, the result is common-impedance coupling — and real EMC problems. This foundations piece breaks down the theory with circuit models, then backs it up with lab measurements showing how ground impedance affects audio, video, and high-current circuits sharing a common return path.