Implantable Biomedical Signal Monitoring Using RF Energy Harvesting & On-chip Antenna

This paper presents the design of an energy harvesting wireless and battery-less silicon-on-chip (SoC) device that can be implanted in the human body to monitor certain health conditions. The proposed architecture has been designed on TSMC 0.18μm CMOS ICs and is an integrated system with a rectenna (antenna and rectifier) and transmitting circuit, all on a single chip powered by an external transmitter and that is small enough to be inserted in the human eye, heart or brain. The transmitting and receiving antennas operate in the 5.8GHz ISM band and have a -10dB gain. The distinguishing feature of this design is the rectenna that comprises of a singlestage diode connected NMOS rectifier and a 3-D on-chip antenna that occupies only 2.5 × 1 × 2.8 mm of chip area and has the ability to communicate within proximity of 5 cm while giving 10% efficiency. The external source is a reader that powers up the RF rectifier in the implantable chip triggering it to start sending data back to the reader enabling an efficient method of health evaluation for the patient. Keywords—Biomedical Monitoring, Eye-pressure monitor Implanatble CMOS IC, Rectenna, TSMC, 3D on-chip antenna