Customized Fixture Adapter for Accurate CM Choke Impedance Measurement up to 100 MHz

Common-mode (CM) chokes are key components in power electronics for mitigating conducted electromagnetic interference (EMI) caused by high-speed switching of semiconductor devices. The impedance information of a CM chokes serves as a useful input to evaluate its EMI suppression performance. This paper proposes a fixture adapter between a vector network analyzer (VNA) and a single-phase CM choke for impedance measurement up to 100 MHz. The parasitics of the fixture adapter are taken into account and de-embedded from the measured data through two-port network theory so that the impedance of the CM choke can be extracted with good accuracy.