Super resolution emission source microscopy using water immersion

A two-dimensional emission source microscopy (ESM) algorithm based on the synthetic aperture radar (SAR) technique is used for EMI source localization. The resolution of the ESM method is proportional to the wavelength of electromagnetic radiation, and at the frequency of 1 GHz, the theoretical resolution limit in air is 15 cm which is too coarse for many practical applications. The resolution can be improved if water is used as the medium between the device under test (DUT) and the receiving probe, leading to a much shorter wavelength. It is demonstrated that by using water immersion it is possible to achieve resolution of 2.5 cm at 1 GHz, which is a 6-fold improvement over a measurement in air.