Troubleshooting EMI Like a Pro

Setting Up a Benchtop Conducted Emission Test

Conducted emission tests can provide reasonably accurate results and also serve as a reliable indicator of radiated emissions, as some of these emissions propagate through cable wiring.

Locating the Noise Source of the 10-30 MHz “Hump”

During conducted emission tests, one of the challenges manufacturers face is the resonance peaks in the harmonic noise somewhere between 10 MHz and 30 MHz. Often, no amount of filtering will eradicate or attenuate the peak.

A Capacitively Coupled Pin Injection Method for Troubleshooting Immunity Issues

Although most modern RF amplifiers have a high voltage device rating against impedance mismatch, special care is needed to prevent impedance mismatch. To avoid impedance mismatch of the power amplifier, often an attenuator is also recommended to be connected between the output of the power amplifier and the flying probe.

Cable Antennas and Ferrite Cores

In this column, the author offers a brief summary of a more systematic approach for using ferrite cores on cables. This summary can serve as a “ferrite core checklist” for design and test engineers.
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