Coupling Path Visualization and EMI Mitigation for Flyover QSFP Connectors

In this article, the energy parcels concept is used to reveal radiation physics and coupling in the entire structure of flyover quad form-factor pluggable (QSFP) interconnection. Flyover QSFP has better signal integrity than legacy surface mounted printed circuit board QSFP technology. To understand electromagnetic interference aspects, a simulation model was built and correlated to measured total radiated power (TRP) for common mode and differential mode excitations for a frequency range of 1-40 GHz. Further, the energy parcels and their trajectories concept were applied to visualize the coupling path by tracking back the energy parcels from outside of the chassis (quiet side) toward a host board inside the chassis (noisy side). Then, high-density regions of energy parcel trajectories guide where to place the absorbing material efficiently and appropriately. Two locations were examined by filling them with electromagnetic lossy material and improvement was validated by TRP simulation and measurement.