A Dual-Band Implantable Rectenna for Wireless Data and Power Support at Sub-GHz Region

Abstract

An arm-implantable rectenna, supported by a compact planar inverted F-antenna (PIFA) and a rectifier, is proposed for wireless data telemetry and power transfer in the Medical Device Radiocommunications Service (401–406 MHz) and industrial, scientific, and medical (ISM) (902.8–928 MHz) bands. The rectifier is integrated into the system by using the antenna’s ground plane delivering, thus, a robust solution for the implanted devices. Each development stage is theoretically analyzed first and then experimentally tested. The antenna size is $16 \\times 14 \\times 1.27$ mm3. The slit/slot loading techniques applied onto the radiator offer the antenna size reduction and the dual-band operation. PIFA’s resonance stability is shown and its radiation and safety responses are addressed. Further, an arm-attached matching layer (ML) is proposed to enhance the wireless power link. Then, an analysis of rectifier circuits is conducted in order to obtain optimum conversion efficiency at low input powers. By following an attentive design process, the final system (rectenna) is built and tested in whole; the measurements verify our approach.