Radar-based microwave imaging for breast cancer detection: tumor sensing with cross-polarized reflections

Microwave imaging for breast cancer detection is based on the difference in electrical properties of normal, fatty breast tissues and tumors. Tumors may be detected by observing variations in microwave signals transmitted through or reflected from the breast. Radar-based breast imaging methods use the reflected signals from the breast to form images, and generally this involves co-polarized reflections. Observation of the cross-polarized reflection was proposed in S.C. Hagness et al. (IEEE Transac. Ant. Propag., pp. 783-791, 1999), and it was shown that the cross-polarized response did not contain reflections from planar interfaces such as the chest wall. In this paper, we further explore the application of cross-polarization to tumor detection. A broadband antenna capable of detecting cross-polarized reflections is simulated, constructed, and measured. The feasibility of tumor detection with cross-polarized reflections is examined through simulations and experimentally.