A Miniaturized CPW-Fed Tapered Slot Antenna in Lossy Environment for UWB Application in Breast Cancer Detection

In this paper, a miniaturized coplanar waveguide fed (CPW-fed) tapered slot antenna (TSA) is introduced for breast cancer detection. Here, a modified CPW to slot-line transition structure with an air-bridge is employed to broaden the transition bandwidth and increase the radiation efficiency. Through these applied modifications, negative features of the original TSA (limitation of transition) and antipodal Vivaldi antenna (bad cross-polarization) are both removed, while all the positive features remained. We have developed a FDTD-UPML method in lossy environment by using Debye model. To validate the results, a prototype of the proposed antenna is fabricated and tested. By immersing the antenna in alcohol ethanol as a lossy coupling medium and inserting it close to a two-layer breast phantom, near-field parameters are calculated in different probe locations. Results show that the proposed structure offers a broad bandwidth of 0.5–19 GHz and also exhibits an appropriate current distribution with high radiation efficiency. Images of energy flux density (EFD) and fidelity factor (FF) confirm the good performance of the antenna in near-field region.