A miniaturized antenna with optimum q-factor and high NFD for UWB microwave imaging

This paper presents an ultra-wideband (UWB) micro-strip patch antenna design for microwave breast phantom imaging system. By optimizing the shape of radiating elements, the antenna achieves UWB characteristics with excellent frequency ratio. The antenna was fabricated and tested in both time and frequency domain analysis. Sufficient agreement between the simulated and measured data was observed. The antenna achieves a wider bandwidth of 8.2 GHz (2.5 GHz to 11.2 GHz) with good gain and radiation pattern. The antenna has optimum design comparing to the theoretical Qfactor and the near field directivity (NFD) is also observed. Effective near-field microwave breast phantom measurement systems with an array of 9 UWB antennas is proposed and the performance is tested with and without tumor cells inside the breast phantom. The backward scattered signals analysis shows that the presence of tumor with higher dielectric constant than normal cells. Thus, the proposed antenna can be a good candidate for microwave breast tumor detection.