An Active Tangential Electric Field Probe for Switching Noise Diagnosis in Power Modules

Wide-band-gap semiconductors have brought about a revolution in the speed of power electronic switching, but electromagnetic interference has become a new burden. In this paper, we present a tangential electric field probe dedicated to the diagnosis of power electron electromagnetic noise. The proposed probe adopts four-layer printed circuit board technology and can measure theExorEyof the tangential electric field. The detection structure adopts enhanced dipole and differential amplifier with a 20 dB gain to improve the detection sensitivity. Through the measurement results, the proposed probe can operate from 100 kHz to 4.6 GHz, which is just right for power circuits. Its unwanted field suppression is above 10 dB, and maximum frequency response reach -25.8 dB at 0.65 GHz. The measurement results of a typical GaN power module demonstrate the effectiveness of the proposed probe.