Harmonic Backscattering and Wireless Power Transfer for Deep In-Body Implantable Wireless Sensors: A Novel Approach

The integration of harmonic backscattering and RF (Radio Frequency) wireless power transfer (WPT) technologies offers a new pathway for powering and communicating with deep in-body implantable medical sensors. This work introduces a novel system that addresses the critical challenges of miniaturization, low power consumption, and robust wireless communication in implantable devices. By employing a voltage doubler rectifier and leveraging harmonic modulation, the system harvests RF energy efficiently and transmits data reliably via harmonic backscattering. The approach separates uplink communication frequencies from WPT frequencies, reducing interference, mitigating self-jamming, and significantly enhancing receiver sensitivity. Experimental validation demonstrates reliable data transmission at receiver sensitivity levels as low as -97 dBm, even under deep implantation conditions. The compact design employs low-cost components, enabling battery-free operation while maintaining high performance. This innovative system presents a scalable and practical solution for longer-lasting, and more reliable devices for diagnostics and therapeutic applications.