Advances in Microwave Near-Field Imaging: Prototypes, Systems, and Applications

Due to microwaves’ ability to penetrate optically opaque media, short-range applications, including medical imaging, nondestructive testing (NDT) and quality evaluation, through-the-wall imaging, and security screening, have been developed. This article addresses some older systems included in prior reviews to provide historical perspective. The focus is on recent active-mode hardware systems for two prominent medical applications currently under investigation, such as early stage breast-cancer and brain-injury detection. Cost reductions in RF manufacturing have enabled many microwave breast-imaging systems to operate at a few gigahertz to obtain a high resolution where the dielectric property provides a significant contrast between malignant and healthy states for some breast tissues, with the notable exception of fibroglandular tissue.