An Imaging System for Electro-Magnetic Noise Source Identification

Yoshio KAMI

IEICE TRANSACTIONS on Communications   Vol.E86-B    No.4    pp.1377-1382
Publication Date: 2003/04/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Electromagnetic Compatibility(EMC)
microwave imaging,  microwave holography,  inverse Fresnel transform,  

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In this paper, we propose a passive imaging system for noise-source identification using time-domain waveform sampling. The fundamental concepts are based on optics theory. A waveform of a diffracted field over an entrance pupil is obtained by a digitizing oscilloscope. The phase distributions over the entrance pupil for each frequency are calculated by using Fourier transform of the acquired waveforms. Thus, an image on the focal plane is reconstructed by using inverse Fresnel transform. The most significant advantage of the proposed method is that an image for each frequency can be obtained separately. We confirmed that the proposed method can be used for practical noise-source identification, by experimentally obtaining images for an emission from personal computers.