Research On Broadband Rectennas For Harvesting Low-power RF Energy

As the development of the Internet of Things,more and more eletronic sensors are used in the society.Microwave power transmission(MPT)has gained a lot of attention as the rapid development of wireless communication.MPT is becoming an effective way to charge low-power electronic devices,such as radio frequency identification(RFID),wireless sensors.Rectennas,which can receive and convert the microwave power to dc power,are crucial parts in MPT systems.Consequently,the research on rectennas has become a hot spot.However,most of those rectennas do not aim to broadband applications and require relatively high input RF power.In this paper,a broadband rectenna using CPS is proposed.A broadband T-match dipole is adopted as the receiving antenna.A silicon Schottky diode is shunted across the CPS as a rectifying device.the CPS rectifying circuit is co-designed with the T-match dipole,and their matching performance is optimized for broadband operation at low input power.Therefore,the rectenna has the characteristics of broadband,low input power,high RF-DC efficiency,which can be applied to a variety of MPT systems.This paper presents a broadband rectenna using the coplanar stripline(CPS).The radiator of the rectenna is a T-match dipole printed on a substrate.A silicon Schottky diode is shunted across the CPS as a rectifying device.The T-match dipole is designed to directly match the rectifying circuit within the operation band so that the bandpass filter between the antenna and rectifying circuit is eliminated.The RF-DC conversion efficiency of the rectenna is higher than 30% within the band from 1.7 GHz to 2.1 GHz at-2.5dBm received power on a857? load,and the highest efficiency is 62.4%.