Research On High Efficiency Rectifier Applied In Microwave Wireless Power Transmission Receiver

The technology of wireless power transmission has gotten more and more attention for the advantages of high mobile flexibility and strong environment adaptation.With the advantages of loss long transmission distance,high transmission efficiency and low transmission,microwave wireless power transmission(MPT)has provide a new way to charge the spacecraft.The microwave wireless power transmission can be divided into two parts: the microwave transmitter and the receiver.The efficiency of rectifying power of the receiver directly determines the overall efficiency of the whole system.Under the circumstances,this thesis carries out a research on the high efficiency rectifying circuit applied in the receiver of the microwave wireless power transmission system.To raise the efficiency of the rectifying circuit in MPT system,this thesis proposes a two-stage AC-DC synchronous rectifier based on single-ended current-driven Class E rectifier.Compared with the single-ended Class E rectifier,the proposed AC-DC synchronous rectifier can make the input impedance constant under several output resistor conditions in order to reduce the rectifying power loss caused by impedance unmatching.Firstly,this thesis gives a detailed analysis of the single-ended Class E rectifier working principles.The input impedance varies a lot when the output resistor changes.Thus,the Buck converter is proposed for impedance matching and also all the components in the circuit are designed.Meanwhile,a self-oscillating resonant driver is proposed in order to make the Class E synchronous rectifier working at microwave frequency.At last,methods to control the preceding stage and to control the impedance for the backward stage are proposed and their design procedures are provided.This thesis provides a detailed method of designing all the components in the Class E rectifier based on its working principles so as to increase the efficiency and the accuracy when designing its parameters.Upon typing in the computer program of its needed input impedance and other restrictions,all the parameters are shown after calculating.This method solves the problem of uncertain resonant components in the Class E rectifier while using the traditional design procedures.A prototype of 50Ω input impedance,10 W output,operating at frequency of approximately 100 MHz was built in the lab.The simulation and experimental results agree with the theoretical analysis,verifying the feasibility of the proposed converters and the correction of the design methods.