bogdan adamczyk

Via placement and trace geometry significantly affect decoupling capacitor performance. This final installment of a three-part series presents conducted emissions measurements across six PCB via topologies, revealing how distance from the power-ground plane pair and via spacing impact EMC results.

Conducted emissions testing on custom PCBs shows how moving a decoupling capacitor farther from an IC can increase emissions across multiple frequency bands. Using CISPR 25 methods, this study compares capacitor placements and via topologies to reveal how distance and inductance shape PDN behavior.

Even perfect shields fail with poor aperture design. Learn how slot orientation, size, and placement affect shielding effectiveness, and discover why multiple small holes outperform single large openings using Babinet's principle.

Understanding how shields perform in the near field requires accounting for wave impedance differences between electric and magnetic sources. This sixth installment derives shielding effectiveness formulas for near-field conditions and reveals a surprising truth: copper outperforms steel at low frequencies, but steel's superior absorption reverses this advantage above 4kHz.

Shielding effectiveness changes dramatically in the near field. This month's column introduces wave impedance concepts for electric and magnetic dipoles, revealing why electric sources behave as high-impedance radiators while magnetic sources act as low-impedance radiators—distinctions critical for designing effective shields close to emission sources.

Discover why copper shields outperform steel at low frequencies but steel dominates at high frequencies. This practical guide presents simplified formulas for calculating electromagnetic shielding effectiveness, revealing the surprising crossover point at 4200 Hz where material performance flips.

Part 4A of a comprehensive shielding series derives two practical approximate solutions from exact electromagnetic theory. For good, thick conductors in far-field conditions, multiple-reflection losses become negligible, significantly simplifying shielding effectiveness calculations for engineers.

Discover the exact mathematical solution for far-field shielding effectiveness of solid conducting shields. Learn how reflection, absorption, and multiple-reflection losses combine to determine a shield's ability to block electromagnetic radiation in real-world applications.

This is the second of seven articles devoted to the topic of shielding to prevent electromagnetic wave radiation. This article discusses the normal incidence of a uniform plane wave on a solid conducting shield with no apertures.

This is the first of seven articles devoted to the topic of shielding to prevent electromagnetic wave radiation. The results presented here are valid under the assumption of a uniform plane wave with normal (perpendicular) incidence on a boundary between two media.