Microwave Holography for EMI Source Imaging

Emission source microscopy technique can be utilized to localize the radiation sources in complex and electrically large electronic systems. In the two-dimensional emission source microscopy algorithm, both magnitude and phase of the field need to be measured, and a vector network analyzer or an oscilloscope has to be used as a receiver, resulting in reduced signal-to-noise ratio and longer measurement time compared to a spectrum analyzer (SA). In this article, a phaseless electromagnetic interference source imaging method is proposed based on microwave holography. The field produced by the device under test is not measured directly, instead, the interference pattern between the emitted field and the reference wave is created and measured as the hologram. The hologram is a real-valued function that can be measured using a SA. The proposed method is validated through measurements for both passive and active devices. The proposed algorithm is efficient and reliable in identifying major radiation sources and determining their location and relative strength.