Flexible Dual-Polarized UWB Antenna Sensors for Breast Tumor Detection

Detection of breast cancer in its early stage is critical for reducing the death rate. In this paper, a compact and flexible breast tumor sensing system is designed using dual-polarized UWB antenna arrays. Each UWB unit is composed of two orthogonally placed circular monopoles, which are printed on flexible and low-profile Kapton polyimide. The antennas are fed by single-side coplanar waveguides for size reduction. A wide band from 3.9 GHz to 19 GHz is obtained, with an isolation of above 16 dB over the operating band. High fidelity factors are achieved at different solid angles, indicating little distortion of the signal and stable sensing ability. To obtain the image of the tumor, eight UWB units are employed surrounding the breast phantom. Using the reflected and scattered signals from the antennas, 3D images of the breast are reconstructed using delay-and-sum (DAS) algorithm. Attributed to the dual-polarized UWB antennas, accurate location and size of the tumors are retained with little clutter. Moreover, the proposed system can detect two tumors with an edge to edge distance of 15 mm. Experiments have been carried out on rotating platforms, with the tumor successfully detected in the measurement. The proposed tumor sensing system is suitable for wearable applications due to its compact size and flexibility.