Frequency and time domain calibration for large Rogowski coils

The SKA needs strong mitigation measures to ensure a radio quiet environment. In an ongoing study, lightning induced RFI is investigated as well as a means to measure and mitigate its effects. The Rogowski coil is chosen as the principle current transducer and its calibration is studied. A time domain calibration approach is investigated and verified with a commercial current probe's calibration data. This approach along with larger Rogowski coils requires an enlarged fixture for calibration. The larger fixtures introduce a mismatch resulting in high reflection loss. Simulations show that by using a dielectric with high permittivity in the calibration fixture a smaller fixture is realisable.