Highly Integrated and Ultra-Compact Rectenna with Wireless Powering for Implantable Vascular Devices

This paper presents a highly integrated and ultracompact implantable rectenna for wirelessly powering implantable vascular devices at 1.4 GHz. The proposed implantable rectenna occupies dimensions of 7× 7× 0.635m$\mathrm{m}^{3}$ and is encapsulated by a biocompatible polydimethylsiloxane (PDMS) package with an overall size of 8× 8× 1.635m$\mathrm{m}^{3}$. The miniaturized implantable antenna is achieved by embedding meandered slots on the radiating patch and open-end ground slot. In addition, a single optimized matching inductor is designed for the matching circuit between the antenna and the rectifier. The rectifier is directly integrated into the radiating patch layer of the antenna using a probe feed. The rectifying circuit, utilizing a single-stage voltage doubler topology, efficiently converts radio frequency (RF) power received by the implantable antenna into proper direct current (DC) power to drive the implantable vascular devices. The integrated matching and rectifying circuit are miniaturized to 4. 87× 2.05× 0.635m$\mathrm{m}^{3}$ and exhibits a maximum simulated conversion efficiency of 67.9% with a load resistance of 3 k$\Omega$ at an input power of 7.5 dBm.