Microwave imaging of breast cancer tumor inside voxel-based breast phantom using conformal antennas

In this paper, contribution of spherically conformal ultra-wide band (UWB) bow-tie antennas on tumor detection capability of a radar-based UWB microwave imaging system, which is currently being developed at the Scientific and Technological Research Council of Turkey-MRC-MİLTAL, is investigated by using an anatomically realistic voxel-based breast phantom through simulation studies. The designed conformal antenna operates efficiently across the band from 1 GHz to 8 GHz, and it´s immersed in a coupling medium in order to get a good impedance matching with the breast phantom. Images are successfully formed by using delay-and-sum (DAS) algorithm for the detection of a spherical tumor model with 2 mm diameter, embedded at 40 mm depth inside the breast. The use of the spherical conformal antenna presents an excellent solution to increase signal energies in the microwave images by around 3.2 dB, as well as to decrease mutual coupling effects between array elements, compared to the same system with planar bow-tie antennas.