Compact configuration of a planar EBG based CM filter and crosstalk analysis

This paper introduces a compact configuration for a planar EBG-based common mode filter in order to reduce its dimensions in the layout phase of a printed circuit board. The performance of the proposed CM filter is studied both in frequency and time domain by looking at the common mode reduction and the correct propagation of the intentional differential signal. The energy coupling from the common mode signal to the power plane cavity resonant modes can create crosstalk problems on other traces crossing the same gaps. The fundamental mechanisms of this effect are investigated and the crosstalk at the near end and far end are quantified and compared to the ideal case of a solid reference plane.