Sensitivity enhancement of super resolution breast tumour imaging with far-field time reversal mirror integrating with multi-layered sub-wavelength patch scatterers

Abstract

We present numerical simulation study of super-resolution imaging of closely spaced sub-wavelength size breast tumours with low cost microwave MIMO bowtie antenna array integrating with near-field planar multi-layered sub-wavelength patch (MLSWP) scatterers by using a monopole as the excitation source. The MLSWP scatterers, serving as transforming structures for the propagation of evanescent waves for sub-wavelength breast tumours imaging with far-field time reversal technique incorporating with bowtie antenna time reversal mirror, are investigated in this paper. The use of the MLSWP scatterers has enhanced the directivity and gain of the traditional monopole resulting in the enhanced scattering amplitudes of the tumour inclusions in the breast. The scattering intensity of the tumours has been enhanced as compared to imaging without the MLSWP scatterers. We propose a tumour imaging scheme using a bowtie antenna array with far-field electromagnetic time reversal for which tumours of sub-wavelength dimensions of 2 mm, 4 mm and 6 mm at sub-wavelength inter tumour distances have been imaged from our simple breast model with super-resolution operating at 2.45 GHz. This will greatly enhance the early imaging of breast tumours in the fight against breast cancer whiles attaining a cost effective biomedical imaging system since the antennas and MLSWP scatterers are low cost microwave components.