An EM Imaging Method Based on Plane-Wave Spectrum and Transmission Line Model

There is a great demand and challenge for the nondestructive detection of an unknown electromagnetic interference (EMI) radiation source inside the printed circuit board (PCB). In this article, an electromagnetic imaging method based on the plane-wave spectrum and transmission line model is proposed. By scanning the radiated field outside the PCB and calibrating the electric or magnetic probe with a reference source, the field inside the PCB can be evaluated, and the image of the unknown radiation source inside the PCB can thus be predicted. The proposed method is validated by simulation and measurement examples. Correlation coefficients between the predicted field and the reference are larger than 0.9, which reveals the good accuracy of the proposed method. This method will be greatly applicable in determining the EMI sources inside electronic devices.