Design and measurement of a tiny wideband antenna for deeply embedded biomedical devices

Abstract

Abstract The increasing demand for compact and efficient implantable medical devices has driven the development of advanced antenna solutions for biomedical applications. This study presents a novel wideband implantable antenna specifically tailored for scalp implantation, operating across two critical frequency ranges: the Industrial, Scientific, and Medical (ISM) band (2.4–2.48 GHz) and the midfield frequency range (1.45–1.6 GHz). The antenna’s compact design, with overall dimensions of 3 × 4 × 0.5 mm 3 , features a 0.25 mm thick dielectric layer constructed from Rogers 4350B ( ε r = 3.66, tan δ = 0.0031) for both the substrate and superstrate. Innovative design elements, including open-ended slots in the radiating patch and closed-ended slots in the ground plane, contribute to its compact size, enhanced impedance matching, and improved bandwidth performance. The antenna achieves a peak gain of −19.92 dBi at 2.45 GHz and delivers an ultra-wide bandwidth of 1836.8 MHz, spanning from 1.0602 GHz to 2.8970 GHz. These characteristics ensure reliable operation in diverse implantation scenarios within the human body, while adhering to IEEE C95.1-2005 safety standards for specific absorption rate (SAR) compliance. Comprehensive performance evaluations were conducted using finite-element simulations in homogeneous tissue environments, employing HFSS and CST software. The simulated results aligned closely with experimental measurements, validating the design’s accuracy and manufacturability. Additionally, a link budget analysis confirmed the antenna’s ability to maintain a robust and reliable wireless telemetric connection, demonstrating its suitability for medical applications and ensuring safe, efficient communication.