Whitepaper
Evaluating EMC Components with DC Bias Superimposed
This Keysight Technologies application note details a method for accurately evaluating EMC components – specifically ferrite beads – under realistic operating conditions. It addresses the increasing complexity of EMC requirements driven by faster data rates, lower voltages, and miniaturization of electronics. The paper highlights the importance of measuring impedance characteristics while applying DC bias to account for inductance saturation, demonstrated using Keysight's E5071C ENA network analyzer in conjunction with a DC power source and electronic load. Two measurement methods are discussed: reflection (one-port) and shunt/series (two-port), with preference given to S21 measurements due to lower noise floors. The note includes details on a sample VBA program for automating the process using the E5071C, the E3633A/E3634A power source, and the 3300A/E3301A electronic load.