Authors : Saravana Selvan, Suenwei , Douglas , Umayal , Gobbi Ramasamy and Mukter Zaman
Abstract: Radio Frequency (RF) harvesting is a process of converting the available ambient RF sources in to Dc electricity which can able to power up the ultra low power wireless sensor networks, charging systems, RFID applications and bio-implantable devices.There is a significant challenge in the design of rectifier part in the RF harvesting system, to improve the output dc power with Power Conversion Efficiency (PCE). The main objective of this study is to choose a suitable device and structure of the RF-DC rectifier circuit in the harvesting system which operates in high frequencies. The rectifying device such as schottky diode and diode connected MOSFET, used in the RF rectifiers are suffered with bad threshold voltage levels which makes a large increase in the channel resistance Ron , reduces the on-drive current and increase in the voltage drop which leads on to high resistive power loss, low power conversion efficiency and acquire very low dc output voltage. To overcome the above issues, a GaN/InN steep slope tunnel FET device is proposed for an efficient structure design . The designed tunnel fet rectifier is thoroughly investigated with different design parameters such as number of stages input dbm, width of TFET, capacitor values and DC current of known load values. The simulation of the circuit shows that it can able to generate a power conversion efficiency of 26.8% for a minimum RF input of -15 dBm at 900 MHz operating frequencies, providing the output dc voltage of 2 V, 4 μA with a load resistive of 500 KΩ.
Saravana Selvan, Suenwei , Douglas , Umayal , Gobbi Ramasamy and Mukter Zaman, 2018. Design of RF to DC Rectifier using Steep Slope Tunnel FET Device for RF Powered Systems. Journal of Engineering and Applied Sciences, 13: 3232-3237.