PCB design

An Arduino-based board with no solid ground return plane makes the perfect "what not to do" test case. Near-field probe measurements, spectrum analyzer captures, and real emissions data reveal why two-layer designs can be EMC trouble — and what it takes to fix them.

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.

Radiated emissions testing is a critical—and complex—step in EMC compliance. This practical guide walks engineers through preparation, equipment setup, and troubleshooting strategies to help identify and resolve emissions issues before they become costly certification failures.

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.

It is common for people doing simulations to make a measurement of a similar set up to validate the simulation. The real issue is whether the tool user understands the problem well enough to capture the important features, and whether the user understands the tool well enough to use it correctly.

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.

Tech-Etch manufactures high-reliability flexible printed circuits on polyimide substrates using advanced manufacturing processes to...