Multichannel EMI Filter Performance Assessment by Mix Mode Injection

Multichannel measurements allow faster evaluation of Insertion Loss (IL) for Electromagnetic Interference (EMI) filters than traditional methods. This paper presents the multichannel measurement technique which enables determining both Differential Mode (DM) and Common Mode (CM) IL. The presented technique requires only one setup instead of the multiple separate setups described in CISPR 17. Furthermore, the measurement speed is increased in the current approach, by a single injection of Mixed Mode to characterize an Electromagnetic Interference (EMI) filter in terms of DM and CM IL. Limitations of this method have been highlighted and described including, Dynamic Range (DNR) and mode interactions. Simulations and measurements have been performed to validate the proposed theory. It has been concluded that a single sweep measurement can be used for determining the IL of an EMI filter.