Passband frequency response measurement of a high voltage differential probe up to 10 MHz

High voltage differential probes are widely used for measurements in power electronics. For accurate measurements in power electronics, the use of probes with flat passband frequency response is indispensable. In this article we present a measurement method to evaluate the passband frequency response of a probe up to 10 MHz. We introduce an oscilloscope based setup, including a calibration procedure with a reference attenuator. Amplitude and phase estimation of the oscilloscope data is done with enhanced versions of the IEEE 1057 and 1251 sine-wave fit algorithms. The feasibility of the presented method is verified by a detailed uncertainty evaluation for the complex valued passband frequency response. The uncertainty assessment is done with two different methods, provided by the Guide to the Expression of Uncertainty in Measurement (GUM) and the associated Supplement 2.