Research On Rectifier Technology For Wireless Power Transmission System

Since Tesla experiments proved Hertz’s theory of wirelesstransmission of radio wave in1899, microwave power transmission (MPT)which is the energy form of electromagnetic waves transmitting from thetransmitting end to the receiving end, has been paid great attention to andgot a rapid development. With the arising of the Solar-Power Satellite (SPS)concept, MPT had been stimulated to a larger extent. At present, thistechnique has been applied to many fields, such as wireless sensors, radiofrequency identification (RFID), microwave driven aircraft and pipelinerobot, etc. Rectifying efficiency is one important performance of thereceiving end in the microwave power transmission system. In this thesis,the MPT and rectifying technologies research were first investigated andsummarized and based on this, the rectifying technique are studied in detailand systemically in the following four parts.First, the rectifying diode is analyzed in detail particularly. Analyticalmethod is used in deriving the closed formula of the rectifying efficiencyof ideal case as a function of the input power and output impedanceseparately. Then, a parallel form rectifier is analyzed and processed tointroduce the joint simulation method. The validity of this joint simulationmethod is illustrated by the measured results of the circuit. The differencebetween simulated results and measured results is analyzed.Then, the influence of harmonics on the rectifying efficiency isstudied. A5.8GHz dual-diode symmetric form rectifier with four orders ofharmonic-rejecting is implemented according to the harmonic-rejectingproblem of rectifiers. An accurate diode model MA4E1317in ADS isadopted in the joint simulation and processing of the circuit mentioned above. The measured and simulated results are in good agreement withover74%rectifying efficiency in the whole ISM band with5.8GHzfrequency center when input power is18dBm.Aiming at the application of low power density, a2.45GHz rectifyingantenna of low power density is proposed with ADS-HFSS co-simulationmethod. The experiment results show that the rectenna have rectifyingefficiency of66.5%with3dBm input power.Finally, the thesis presents a harmonic-rejecting dual-frequencyvoltage doubler rectifier. The rectifier presents a good performance in thecenters of the two ISM bands which is2.45GHz and5.8GHz. Rectifyingefficiencies of72.5%and70.3%are reached respectively.