Dielectric-filled slotline bowtie antenna for breast cancer detection

An ultra-wideband dielectric-filled antenna has been designed for the purpose of breast cancer detection. The antenna geometry is a modified version of a slotline bowtie hybrid, which is immersed in a dielectric medium, and fed with an integrated ultra-wideband balun. Simulations were performed on both the balun and the antenna separately. The antenna had a simulated time domain near-field beamwidth of 32/spl deg/. A return loss of 10 dB was obtained from 2.5 to 9 GHz, and 5 dB from 1 to 10 GHz. Both bandwidths were slightly smaller than simulated. A prototype was constructed and feasibility tests were performed on tumour models immersed in a breast phantom material. Measurements demonstrate detection of a 7 mm diameter tumour at a depth of 4 cm from the aperture.