emc concepts explained

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.

This column examines inductor impedance evaluation using S₂₁ parameters with network analyzers. Comparing two-port shunt and series methods across multiple inductors, it concludes that the two-port series method provides significantly more accurate measurements when compared with manufacturer data.

This first installment in a two-part series evaluates inductor impedance using S11 parameters across one-port shunt, two-port shunt, and two-port series methodologies. Experimental results reveal significant discrepancies between measured values and manufacturer specifications, highlighting limitations in S11-based impedance characterization techniques.

This article explores S₂₁ parameter methods for measuring capacitor impedance. Comparing two-port shunt and series techniques with established benchmarks reveals the two-port shunt method delivers superior accuracy across multiple capacitor values and frequency ranges.

Ever wonder how accurate your capacitor measurements really are? This deep dive into network analyzer techniques compares three different methods for measuring impedance, uncovering surprising limitations in standard s₁₁ parameter approaches that engineers should know about.