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 × 42 × 1.27 mm3 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.