Effects of imbalance on conducted immunity of a PLC link onto a DC power-bus for spacecraft

In this work, conducted-noise propagation in a Power Line Communications (PLC) link implemented on a spacecraft dc power-bus and involving differential signaling is investigated by resorting to modal analysis. The study mainly focuses on the detrimental effects on conducted immunity owing to the imbalance possibly introduced by the power units and the PLC modems. To this end, a suitable circuit interpretation of the propagation paths associated with common-mode (CM) and differential-mode (DM) components of the noise generated by the dc-dc converters is proposed, and the significant role that CM rejection properties of the modems play on immunity performance of the PLC link is outlined.