Miniaturized Implantable Rectenna for Far-Field Wireless Power Transfer

A compact rectifier-antenna (i.e. rectenna), integrating a compact patch antenna with a rectifier, is designed for the far-field wireless power transfer of implantable medical devices. The proposed rectenna operates in the Industrial, Scientific and Medical (ISM) band of 902-928 MHz. The sizes of the antenna are miniaturized to π × 4
²
× 1.27 mm
³
by etching a meandering structure on the radiation patch. Through exciting two adjacent resonant frequencies, the simulated impedance bandwidth is extended to 36.6% (0.78-1.13 GHz) with |S11| below -10 dB. Furthermore, on the back of the antenna, a voltage doubled rectifier circuit is designed and analyzed. The simulated RF-to-DC conversion efficiency can be up to 58.3% at -5 dBm.