Optimized matching liquid with wide-slot antenna for microwave breast imaging

In this paper, we introduce an optimized matching liquid together with a wide-slot ultra-wideband antenna to be used in a breast microwave imaging system. The slot antenna is small with 13 mm × 14 mm × 0.625 mm dimensions so that many of them can be placed around a breast. The matching liquid is needed to effectively couple the microwave signal into breast tissues. Exhibiting a suitable permittivity and moderate loss, the matching liquid is a mixture of 83% sunflower oil with 17% distilled water. We build a phantom in order to investigate the penetration of microwave signal into the breast tissues. Experimental measurements and simulation results indicate that this matching liquid provides, nearly, the maximum scattering power from inside of breast tissues in interval [2.5, 7 GHz] that is an appropriate frequency range for breast imaging.