A Compact Wider Bandwidth Implantable Antenna for Implanted Biomedical Devices

Abstract

The increasing demand for real-time health monitoring has propelled substantial developments in wireless implantable medical devices, especially for organ-specific applications like kidney diagnostics. These systems utilize implantable antennas to facilitate biotelemetry communication between internal and external monitoring devices. Designing antennas for implantation presents numerous obstacles, particularly in intricate anatomical areas such as the belly. Significant signal attenuation, size constraints, limited amplification, and compliance with safety laws constitute the limitations. This work presents the design and characterization of a compact, low-profile, high-gain implantable antenna optimized for kidney applications operating in the 2.4-2.5 GHz ISM band. The antenna was designed with a coaxial feed placed at its center. Four L-shaped slots are etched to obtain the resonant frequency. Three slots are etched in the radiating patch and connected with L-shaped slots. These slots play a crucial role in obtaining compact sizes. Four shorting pins are employed to improve the impedance matching and achieve a broader bandwidth. The antenna is simulated in a human tissue phantom model representing realistic abdominal conditions. The measured fractional impedance bandwidth of 40.82%, simulated gain of -23.57 dBi, and acceptable SAR have been obtained. The antenna has a compact, low profile, and is suitable for implanted biomedical devices. © 2025 IEEE.