A novel differential mode rejection network for conducted emissions diagnostics

A differential mode rejection network (DMRN), a device which separates common mode noise from differential mode noise in a line impedance stabilization network (LISN)-based conducted emissions setup, is described. Although it is not a filter, its function is analogous to that of a filter. The DMRN filters out differential mode, and passes common mode unfiltered. The differential mode is attenuated by more than 50 dB, and the common mode noise is attenuated by less than 4 dB. Applications of the DMRN are discussed for filter design and troubleshooting, and electromagnetic interference source suppression is briefly described. Mathematical analysis and hardware implementation of the devices are explained