Search

Extracting electromagnetic patterns by near field scanning can provide concrete information about a device under test (DUT), which benefits a lot when locating EMI sources. In this paper, we extracted the electromagnetic pattern of DUT under different operation state and classify the pattern with a machine learning algorithm for simplifying post-process procedure and better EMC engineering. The result showed different operation state lead to different electromagnetic emission.

In this paper, an experiment to distinguish the spatial resolution of different magnetic probes is executed. Different from traditional measuring method of spatial resolution by using one microstrip line, we measured the spatial resolution by changing two adjacent microstrip lines with space distances from 3 mm to 0.6 mm. By analyzing the test results, we can distinguish the spatial resolution of different probes.

The spatial resolution of probe is defined for a 6-dB level drop point from the peak point close to the edge of the microstrip line. However, this definition is not clear for strongly coupled traces. If the spacing between adjacent traces is small enough, the probe may not detect multiple sources. In this paper, near fields above differential microstrip lines are investigated numerically and theoretically for probe characterization of spatial resolution. Results show several limiting cases for the probe to discriminate two RF sources in close proximity. It is discovered that two traces can be easily distinguished with differential mode excitation, while the detection for the common mode excitation cases is affected by probe height and trace spacing.