A Differential-Mode and Common-Mode DC-Bias VNA Measurement Setup for Power 4-Port Devices

A measurement setup for 4-port power electronic components is presented. The setup allows for the devices under test (DUT) to be DC-biased up to 10 A. The usable frequency range of the setup is from 50 kHz to 1 GHz. The usable frequency range can be extended down to 9 kHz (in compliance with CISPR 16-2-1) by using suitable bias tees, with otherwise no changes to the measurement setup. Therefore this work serves as a proof-of-concept for the measurement setup. S-parameter measurements of a common mode choke (CMC) are presented. Measurements with the proposed setup are compared to a reference measurement without the bias tees. These measurement results show that the influence of the bias tees is negligible, as was intended. Furthermore measurement results of the CMC under DC bias conditions are presented. A possible conversion of the S-parameters to the series impedance of the CMC is also shown to illustrate the possible applications of this measurement method.