Wireless Charging System For Terminal Devices

Now,smart phones are becoming more and more popular,and the features are more and more colorful,but these features also increase the burden of the battery.People want to charge anytime,anywhere on the phone,but traveling to carry the charger will feel no convenience.Therefore,wireless charging technology entered people's lives.The use of data lines to charge the phone is not only faced with the problem,but also facing that the standard is not unified.Wireless charging does not exist these problems,and can charge a number of devices at the same time.But most of the smart phones on the market today use metal back shells,and metal back shells can have a serious impact on the efficiency of wireless charging,and even lead to its inability to work.This paper mainly studies the wireless charging antennas of metal rear shell mobile phones.In this paper,the wireless charging method is introduced and analyzed in the near field,and the working control flow of the resonant wireless charging system and some related parameters are explained.And the transmission principle of magnetic resonance wireless charging is explained by the theory of coupling mode.The transmission efficiency is analyzed by equivalent circuit theory,and the energy loss was reduced by eddy current theory.Some efforts have been made to reduce the size of the antenna by means of equivalent circuit and finite element simulation,so that it can be reduced to a centimeter size.Finally,several wireless charging antennas are designed,including the wireless charging antenna based on the principle of magnetic resonance and the dual-mode wireless charging antenna,which also supports the principle of electromagnetic induction coupling,so that it can be embedded into the metal rear shell mobile phone to work and minimize its energy loss,but increase efficiency.In the experimental test,not only the use of a vector network analyzer on the transmission coefficient was tested,but also a transceiver is built and test.Through the simulation and testing,this paper validates the viewpoints and schemes,which provides a reference for further research.