Design And Application Of Rf Wireless Charging System

The rapid growth of science and technology has made small intelligent electronic devices more and more common in people’s daily life,so that how to continuously supply energy for these electronic devices becomes an urgent problem to be solved.RF wireless technology is mainly about gaining electrical energy by converting RF energy in the environment.Although this technology has the advantages of long transmission distance,safety and stability without pollution,there are also disadvantages such as large antenna size and low transmission efficiency.In this thesis,we focus on the RF collection antenna module,RF DC conversion module and subsequent load module in RF wireless charging system and complete the physical design of each module.First,this thesis investigates the antenna-related technologies,designs three antenna structures that can be used for RF wireless charging systems,and processes and manufactures the antennas in kind.The first one is a tri-band antenna loaded with a metamaterial structure.In the research process of this antenna,as the design of a new kind of metamaterial structure characterized with negative refraction is done,by adding this type of metamaterial structure to the conventional dual-band patch antenna and defect treatment on the ground end of the antenna,an antenna structure that can cover three frequency bands of 2.3 GHz-2.6 GHz,4.2 GHz-4.6GHz,and 5.3 GHz-5.9 GHz is designed.The second antenna bases on adding slots to the ordinary single-band PIFA antenna to generate the second and third band,and by optimizing the antenna structure,the three-band PIFA antenna that can meet the using requirements of 915 MHz,1.8 GHz,2.4 GHz is got,and the maximum gain of the antenna can reach 5.2 d Bi.The third antenna is the broadband circularly polarized antenna,by adding symmetric By adding symmetric open resonant ring and grounding plate with slit defect to the monopole patch antenna,the symmetric open resonant ring makes the antenna produce broadband circularly polarized radiation,and the slit defect grounding effectively excites the antenna high frequency band and expands the bandwidth of the antenna,according to the experimental results,the return loss of the antenna in 1.8 Ghz-6.5 Ghz is lower than-10 d B,and there are multiple circularly polarized resonance points,and the maximum gain of the antenna can reach 2.9 d Bi.Secondly,this thesis paper studies the RF-DC conversion module and proposes two RFDC conversion methods,passive conversion and active conversion.The passive conversion is mainly through the rectifier circuit topology research and analysis,and based on Greinacher full-wave rectifier circuit for the design of RF DC quasi-conversion module,and impedance matching of the conversion circuit.The active conversion circuit is based on the P2110 B as the main chip of the conversion circuit,and the peripheral circuit is designed to realize the RF-DC conversion function.Finally,the selection of the chip and the design of the peripheral of the micro-energy management circuit and the selection of various loads are used to verify the feasibility of the RF wireless charging system designed in this thesis by testing and applying the whole system with an embedded system.The RF wireless charging system designed in this thesis is characterized with long distance of electric energy transmission,stable transmission energy and wide usable frequency band,which has certain scientific significance and application value for the study of wireless charging system.