Review and Bandwidth Measurement of Coaxial Shunt Resistors for Wide-Bandgap Devices Dynamic Characterization

Coaxial shunt resistors are very useful for measuring the ultra-fast current in wide-bandgap device switching transients. One of their major drawbacks is the relatively large parasitic inductance. The traditional coaxial shunt resistors are reviewed and the relationship between energy rating and parasitic inductance is determined. The parasitic inductance can be greatly reduced with a lower energy rating. A measurement method for characterizing their up to GHz bandwidth is also reported. Lower than expected bandwidth was observed and a fix using measured transfer characteristics is therefore described.