Spherical Scanning 3-D Microwave Imaging of Near-field Scatterers
Mutually Coupled With an Antenna Array
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In this article, we propose a 3-D synthetic aperture imaging method with
spherical antenna scanning to identify scatterers located close to an
antenna array, such as fixtures or support of the antenna. Previous
studies have shown that 2-D and 3-D synthetic aperture imaging
techniques with planar, circular, and cylindrical scanning can
successfully reconstruct spatial images of near-field scatterers. The
spherical scanning approach considered in this article is expected to
improve the 3-D image resolution because more angular diversity can be
achieved in the elevation direction. However, as we show in this study,
simple extension of the previous techniques to the spherical case
results in undesired blur artifacts in the reconstructed image. To
overcome this problem, we introduce a correction factor in the image
reconstruction. The proposed imaging algorithm is validated by numerical
electromagnetic simulation based on the method of moments.