Design of high gain miniaturized WPT rectenna for implantable biomedical applications

Implantable medical devices (IMDs) have become indispensable for treating various health disorders and monitoring individual well-being as a result of significant technical breakthroughs in the field of biomedical technology. This article describes a wireless powering technique at 2.45 GHz for low power devices such as IMDs. The design incorporates a rectangular patch antenna that exhibits peak gain of 2.1 dB and impedance bandwidth of 620 MHz with compact size of 71.4 mm3. The antenna is simulated within a three-layer phantom model replicating the human body to evaluate its performance, which produces −21.4 dB peak gain and 600 MHz–10 dB impedance bandwidth. A full wave rectifier aided by matching network is used to accomplish optimal conversion of RF signal to DC power. The constructed prototype is tested in a saline solution, and the measured results closely match the simulation results. Specific Absorption Rate (SAR) is calculated using a phantom model and a head model for assessing patient safety and biocompatibility. The proposed antenna has SAR values of 5.12 W/kg and 3.13 W/kg are exhibited by proposed antenna inside three layer phantom model and human head model.