Investigation of Near Field EMI in Ferrofluid Based Miniature Electronic Devices and Systems

This paper evaluates the near field electromagnetic interference (EMI) in a ferrofluid based miniaturised cooling mechanism. Ferrofluid coolant mechanism with 1.0T magnet was modeled with thermal plate for efficient thermal management of miniaturised 30Watts DC-DC converter module. The setup was modeled to drive the resistive load (30Watts) for multi output voltages 5V@4A & +/-12V@0.75A of the converter module. Near field (E & H) EMI peaks were detected in narrowband frequency spectrum of 1.8GHz, 2.5GHz and 5.7GHz at a distance of 4cm from the source of radiation. It was investigated that the radiated EMI peaks decreased by 7dBuV with the increase in 16% temperature of ferrofluid. It was concluded that ferrofluid based cooling mechanism can efficient dissipate the heat load but at low temperatures, ferrofluid may influence the EMI effects in electronic circuits and systems.