A Wideband and Low-SAR Antenna Design at 2.45 GHz for Biomedical Applications

Abstract

In this paper, a miniaturized implantable antenna is designed for biomedical applications operating within the industrial, scientific, and medical band (ISM, 2.4–2.48 GHz). The proposed implantable antenna has a compact size of 5.5 × 5.5 × 0.64 mm and is manufactured using a biocompatible substrate, Roger RO3010 with permittivity of εr=10.2 and losstangentof tan(δ)=0.0022. To enhance safety, a superstrate and a silicon coating around the antenna are employed to isolate the antenna from the surrounding biological tissues. The simulation software from the HFSS and CST studio suite was utilized to simulate and optimize the proposed implantable antenna, followed by fabrication and testing. The simulation of the proposed antenna was evaluated in terms of its reflection coefficient and gain within a three-layered body phantom, while the testing of the proposed design was carried out using minced pork. The proposed implantable antenna exhibits an 811 MHz bandwidth and a –21 dBi measured gain at 2.45 GHz. Furthermore, for safety evaluation, the specific absorption rate (SAR) analysis was conducted and was found to be within standard limits. The simulated and measured results show a strong correlation, demonstrating that the antenna delivers state-of-the-art performance for implantable biomedical applications.