Toward Breast Tumor Detection: A Miniature Antenna for Industrial, Scientific, and Medical (ISM) Band Implantation

Breast cancer diagnosis using implantable biomedical antennas offers a promising alternative to conventional imaging techniques due to their potential for continuous monitoring and minimal invasiveness. This paper presents a miniaturized antenna with dimensions of 3 ȕ 3 ȕ 1.27 mm3, specifically designed for implantation in breast tissue to detect the presence of tumors. The objective is to evaluate the antenna's ability to detect breast tumors by first analyzing its reflection behavior (S11) in implanted conditions, both with and without tumors. Subsequently, a second external antenna is introduced in free space to assess transmission performance at varying distances. To further assess transmission performance, a second external antenna is introduced, and the system is tested at varying distances and orientations (face-to-face and side-by-side). The antenna operates at 2.45 GHz and is tested in both skin and breast tissue phantoms with embedded tumors of different sizes and positions. Key performance metrics such as S-parameters, gain, transmission coefficient, and group delay are analyzed. Simulation results show gain values of -31.28 dB in skin and -17.78 dB in breast tissue. Patient safety is confirmed through specific absorption rate (SAR) analysis, with a maximum input power of 2.3 mW. The proposed design shows strong potential for breast cancer detection due to its small size, consistent performance in various antenna positions, and compliance with SAR safety standards.