Research On High Efficiency Microwave Rectenna

As a new way of energy transmission,wireless energy transmission is gradually entering people’s life.Compared with the traditional wired energy transmission,it no longer needs wires to connect electronic equipment,but supplies power to electronic equipment through wireless way.In the far-field wireless energy transmission system,microwave rectenna is the most important system at the receiver end,It converts the received electromagnetic wave into DC energy efficiently and supplies it to the load to complete the process of energy exchange.This paper summarizes the research status of rectenna in earlier years and recent years,and summarizes different types of rectenna technology.The purpose of this paper is to design a high efficiency microwave rectenna working at 5.8GHz.5.8GHz belongs to ISM band,which is the higher frequency band of WLAN.Choosing 5.8GHz is also to use the electromagnetic wave signal in this band to realize the process of wireless charging for electronic equipment.In this paper,the rectenna system is divided into receiving antenna and rectifier circuit.The influence of polarization,gain,bandwidth and radiation efficiency of receiving antenna on the whole system is analyzed,and two receiving antennas with different performance indexes are designed.In the research of rectifying circuit,this paper discusses the influence of various parameters of diode on the rectifying efficiency of the circuit in detail,gives the design process of rectifying circuit,how to select the appropriate rectifying diode,explains the function of matching circuit and DC path filter in the circuit,and designs three rectifying circuits working at different input power levels,Considering that the impedance of the antenna is not constant,the circuit is optimized by CST and ADS cosimulation,and the simulation results of high conversion efficiency are obtained: the conversion efficiency of10 d Bm circuit can reach 70%,that of 18 dbm circuit can reach 65%,and that of30 d Bm circuit can reach 62%.The measured results show that the 18 dbm circuit can output 8V DC voltage and the 30 d Bm circuit can output 6.5V DC voltage.