Analysis and improvements of precision coaxial current shunts for direct measurement of ac current

Coaxial current shunts for currents from 10 mA to 20 A have been constructed. They have been calibrated for AC/DC current difference at frequencies up to 30 kHz. A lumped element model was made for each shunt, from which a frequency response and input impedance were derived. Comparison to actual measured frequency response and measured input impedance results show good agreement of the developed model.