Fast Quantitative Microwave Imaging With Scattered-Power Maps

Microwave Imaging by Means of Lebesgue-Space Inversion: An Overview

“…Generally, this is not true in Banach spaces. However, thanks to the Asplund Theorem, from (16) and by using again the chain rule for the derivatives of composite functions as in (9), the subgradient of the residual functional 1 r F (x n ) − y r Y at point x n in Banach spaces can be computed explicitly as:…”

“…Consequently, proper inversion procedures need to be devised, to consider both these theoretical problems. To this end, several approaches have been proposed in the last years [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. They have been investigated in the context of Hilbert spaces, in most cases.…”

A Tomograph Prototype for Quantitative Microwave Imaging: Preliminary Experimental Results

“…Furthermore, appropriate inversion procedures, able to exploit the available a-priori information about the target, should be used in order to process the measurements made available by the hardware. In this framework, several interesting approaches have been recently introduced [9][10][11][12][13][14][15][16][17][18]. On the one hand, they have been designed in order to improve the capabilities of the so-called qualitative methods, which are aimed at retrieving only the presence/shape of targets, as well as some particular features of interest.…”

Frequency-based microwave medical imaging techniques

“…The imaging algorithm can be categorised based on the utilised frequency bandwidth e.g., single frequency, narrow-band multi-frequency, or ultra-wideband (UWB). In this case, the microwavebased imaging techniques can be divided into two main types of tomography [6]- [33] and beamforming [34]- [48]. Due to time-consuming nature of tomography-based techniques, they are mostly applicable to single frequency or narrow-band multi-frequency signals, while beamforming methods require wideband signals to create accurate images.…”

“…The success of these techniques is highly dependent on the quality of the used model for forward problem solving. Therefore, an alternative class of methods based on the contrast source inversion method [30] with capability of solving the ill-posed inverse problem without a forward solver are proposed [31]- [33]. In these techniques, two sets of linear equations are solved in each iteration instead of solving the forward problem.…”