Microwave breast tumor detection: antenna design and characterization

Microwave detection of cancerous tumors has been of great interest as an alternative or a complementary method to ionizing radiation methods such as computed tomography or mammography. Microwave imaging of the human body or its parts has been investigated over a considerable period of time. Limited detection capabilities and computational complexities hamper practical implementation and the promise of clinical use of these techniques. Among various non-superficial tumors, breast cancer tissue has significantly different electrical properties at microwave frequencies from those of healthy tissue. This feature resulted in a very promising approach to cancer detection. Furthermore, this new approach avoids many complexities of microwave imaging. It involves the identification of regions of increased scatter as opposed to directly imaging tissue electrical properties. The identification is based on techniques previously used in ground penetrating radar with suitable modifications. In our research, we have further explored this means of breast tumor detection, but with a considerably different system configuration and signal processing. Our approach appears more amenable to practical implementation, and the preliminary evaluation yielded encouraging results (Fear and Stuchly 1999). In this contribution several antenna designs are evaluated for effective radiation of the ultrawideband pulse which is used for tumor detection.