Near Field Scanning-Based EMI Radiation Root Cause Analysis in an SSD

In modern portable electronic devices, solid-state drives (SSDs) are commonly used and have been identified as one of the dominant electromagnetic interference (EMI) noise sources that can cause RF desensitization issues. In this paper, the EM emission source from an SSD module is identified and analyzed using near field scanning and dipole moment source reconstruction. The identified noise current path including the power management integrated circuit and the decoupling capacitor is validated with the assistance of full-wave simulation. The measured noise voltage is used as an excitation in the simulation and the simulated near fields showed a good correlation with measured near fields in both pattern and magnitude. Based on the validated radiation mechanism, an optimized layout is proposed and validated in simulation reducing the far field radiation by 10 dB.