UWB microwave imaging via modified beamforming for early detection of breast cancer

Ultra-wideband (UWB) microwave imaging is a promising technique for detecting early stage breast cancer, which exploits the significant contrast in dielectric properties between normal and malignant breast tissues. In this paper, we have proposed a new modified compensation method and beamforming technique for microwave imaging. We used a three dimensional (3-D) Finite Integration Technique (FIT) based breast model, with normal breast tissue, supported on a layer of chest muscle and covered by a thin layer of skin. A small sized (1 mm diameter) tumor is placed within the breast tissue layer. A pair of rounded-edge bow-tie antennas at crossed position is used for transmitting and receiving microwave signals. This antenna pair is then placed at different positions over the breast surface and the incident and backscattered signal at each position are stored. Backscatters are then processed to eliminate artifacts. Finally they are passed through the beamformer and an image is formed. The beamformer is designed with adaptive weighting to compensate both propagation attenuation and lossy medium effect. Despite using the traditional delay-and-sum approach, new delay-and-product technique is used in beamforming. This modified beamforming approach is shown to outperform its previous counterparts in terms of resolution and sensitivity.