Compact Dual-Band Biotelemetry Antenna: Circular Polarization, Enhanced Gain, and Wireless Power Transfer Capabilities

Wireless biomedical implants, vital for monitoring organ functions and detecting cognitive disorders, rely on implantable antennas to establish communication with external dev...vices. The challenging task of implanting antennas within the human body involves addressing issues like tissue absorption and the complex internal environment. Antenna design must consider miniaturization, biocompatibility, Specific Absorption Rate (SAR), and efficient radiation characteristics. Recent advancements explore high dielectric substrates, meandered resonators, metamaterials, and flexible substrates to improve antenna performance and size. While progress has been made, further advancements are needed to seamlessly integrate smaller antennas into implantable devices without compromising performance. This project introduces a highly specialized ultra-miniaturized antenna system explicitly designed for biomedical implants. The proposed antenna, measuring as small as 0.04λ × 0.04λ × 0.003λ, supports dual-channel communication at 910 MHz and 2.45 GHz frequencies with circular polarization. The system showcases notable features, including a wide impedance bandwidth and favorable axial ratio (AR) behavior in both operational frequency bands, thereby augmenting the antenna's overall performance. Introducing an artificial magnetic conductor in the proposed antenna leads to significant gain enhancement and robust circular polarization behavior at both operating frequencies. The proposed ultra-miniaturized antenna will seamlessly integrate into the system's electronic components. Moreover, the project seeks to incorporate an additional goal to advance wireless power transfer (WPT) technology by converting radio frequency into an electrical signal. This entails establishing a WPT connection by connecting the receiving antenna – our implantable antenna – with a novel transmitting (Tx) element to be placed outside the human body and featuring dual-band and circular polarization. Two low- and high-permittivity superstrates separated by an air gap will be utilized to optimize the Tx's gain. This structural refinement notably enhances the proposed WPT system's power transfer efficiency. Subsequently, prototypes of the envisioned system are to be manufactured for experimental evaluation. The assessment of the proposed system will involve using minced meat and a saline solution. The measured outcomes from the constructed system prototype are expected to align closely with the simulated results. Specific absorption rates (SAR) and link margins will also be calculated to ensure health safety and dependable communication. This forward-looking project underscores the transformative potential of innovative healthcare technologies, fostering a brighter and healthier future for all.