A miniaturized SC-DGS tapered-fed notched UWB antenna designed for breast tumor detection applications

Abstract This research presents a compact ultra-wideband (UWB) antenna with a single band-notch, specifically designed for non-ionizing and contactless breast tumor detection. The proposed antenna features a crescent-shaped patch coupled with a tapered microstrip line feed on an FR−4 substrate, integrated with a semicircular defected ground structure (SC−DGS). The crescent-shaped radiator is derived by modifying a conventional circular patch, strategically removing a section to enhance impedance matching and bandwidth performance while maintaining a compact size. The design process involved parametric optimization using CST Studio Suite 2021 to ensure efficient UWB operation and stable radiation characteristics. The optimized antenna has dimensions of 20 × 22 × 1.5 mm 3 and achieves a measured impedance bandwidth of 6.42 GHz (6.08−12.50 GHz). To mitigate interference with X−band downlink satellite communications, a notch band from 8.0 to 8.7 GHz is introduced through the SC−DGS. Performance evaluations, conducted in both time and frequency domains, demonstrate omnidirectional radiation patterns, a peak gain of 4.5 dBi, and a radiation efficiency of 80% across the operational bandwidth. After fabrication, the antenna was experimentally tested, showing excellent agreement with simulation results. Additionally, breast tumor detection simulations were performed using S 21 parameters and specific absorption rate (SAR) metrics in both tumor and non-tumor scenarios. The results highlight the antenna’s sensitivity to dielectric contrast in breast tissues, enabling effective tumor localization. Furthermore, the SAR values remained below the safety threshold of 1.6 W/kg, ensuring compliance with medical application standards. The proposed detection method offers key advantages, including non-invasiveness, safe operation using non-ionizing electromagnetic waves, and suitability for early-stage breast cancer screening. These findings demonstrate the potential of the proposed microwave antenna as an efficient and safe solution for breast tumor detection.