radiated emissions

Ken Wyatt walks through pre-compliance radiated emissions testing for automotive modules under CISPR 25 and military products under MIL-STD-461, including spectrum analyzer setup and how to work around ambient RF interference on a home-built test bench.

Turning a spectrum analyzer reading into a real E-field number takes more than eyeballing the display. This installment walks through the gain and loss calculations, test setups, and ambient signal workarounds that determine whether your pre-compliance data actually holds up.

Third-party EMC chambers can cost millions to build, so what does an accurate in-house setup actually require? This first installment breaks down the analyzers, antennas, preamplifiers, and tripods needed for radiated emissions pre-compliance testing, plus real-world test locations that stand in for a proper chamber.

A simple antenna positioned right on your bench can reveal radiated emissions in real time. Learn how to separate product harmonics from ambient RF noise, track down capacitive and inductive coupling paths, and use copper tape and foil to hunt down leaky seams and apertures.

When cables become the culprit in radiated emissions failures, an RF current probe can catch what near-field probes miss. This installment of EMC Bench Notes walks through measurement technique, transfer impedance math, and a downloadable E-field calculator for pass/fail estimation.

MIL-STD-461H dropped in April 2026 with no new requirements and no new test equipment — so what changed? Ken Javor breaks down every substantive update, and why most of them exist to stop EMC lawyers from gaming the standard.

Dropping a pre-certified radio module into your product sounds like a compliance shortcut — but integration choices can still land you back at the test lab. Cory Bradshaw and Craig Brandt explain what manufacturers need to get right before and after the module goes in.

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.

Spectrum analyzers are the go-to tool for diagnosing conducted and radiated emissions — but knowing how to configure them makes all the difference. Kenneth Wyatt walks through key settings, trace strategies, and practical tips for getting reliable results on the bench.

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.