Three-Dimensional Near-Field Microwave Holography for Tissue Imaging

Abstract

This paper reports the progress toward a fast and reliable microwave imaging setup for tissue imaging exploiting near-field holographic reconstruction. The setup consists of two wideband TEM horn antennas aligned along each other's boresight and performing a rectangular aperture raster scan. The tissue sensing is performed without coupling liquids. At each scanning position, wideband data is acquired. Then, novel holographic imaging algorithms are implemented to provide three-dimensional images of the inspected domain. In these new algorithms, the required incident field and Green's function are obtained from numerical simulations. They replace the plane (or spherical) wave assumption in the previous holographic methods and enable accurate near-field imaging results. Here, we prove that both the incident field and Green's function can be obtained from a single numerical simulation. This eliminates the need for optimization-based deblurring which was previously employed to remove the effect of realistic non-point-wise antennas.

Three‐dimensional holographic imaging using data collected over cylindrical apertures

“…To overcome the limitations due to the far‐field approximations, in near‐field imaging applications, the data for the incident field and Green's function have been obtained via simulations in Refs. . In practice, often, the fidelity of the simulation models, although better than the analytical approximations, may still be too low to ensure good image quality.…”

“…In all the previously proposed near‐field holographic imaging techniques, the data acquisition is performed over a rectangular aperture. Here, we propose acquisition of the wideband scattered waves over a cylindrical aperture.…”

“…Data acquisition over a cylindrical aperture, necessitates the use of modified processing techniques as compared to Refs. . This is due to the periodic nature of the scattered waves and the contrast function with respect to the azimuthal direction.…”

Three-dimensional short-range microwave holographic imaging algorithm and imaging system scheme

“…The research on three-dimensional short-range microwave holographic imaging has been growing rapidly in recent years. Areas such as animal tissue imaging [10], influences of polarization data on image quality [11], the imaging of larger objects [12], have all been studied in depth, and further the superiority of three-dimensional short-range microwave holographic imaging technique is also validated by the phase radiation patterns [13]. Domestic research focuses on microwave holography measurement [14], microwave holographic antenna [15], short-range millimeter wave holographic imaging technology [16].…”

Two-dimensional short-range microwave holography algorithm and convolutional gridding

“…However, this short-range millimeter wave holography imaging has many shortcomings, such as it only collected the back-scattered, and also assume that the incident field and the Green's function of target for the spherical wave to deduce the algorithm. For the inadequacies of short-range millimeter wave holography imaging technique, R K Amineh et al, researchers of McMaster University, proposed a new type short-range microwave holography imaging technique [6][7][8][9][10]. It collected the scattered data include not only back-scattered but also forward-scattered.…”