The Design Of NFC Hardware System Of The Handheld Mobile Terminal

With the rapid development of handheld mobile terminal,it has been gradually integrated into people's lives and has become an indispensable part of them.Meanwhile,it is expected that this all-in-one handheld mobile terminal can provide ease and convenience by replacing some tools used in daily life such as keys and wallets.With the development of NFC(Near Field Communication)technology and the popularity of intelligent terminals,NFC products are gradually enriched.NFC applications play a more and more important role in people's lives.Firstly,the thesis states clearly the research background and significance of NFC technology as well as the status quo of the study at home and abroad.By analyzing the technical advantages and the problems of its application in the field of mobile payment as well as its future developments.The thesis aims to find a reliable,high performance and general hardware solution from chip makers who provide other than standardized cell phone processor platform solutions.Its research focus is on the design and optimization method of NFC antennas suitable for the practical engineering application.The ultimate goal is to design a high performance handheld mobile terminal for the logistics and express industry,whose NFC performance is better than that of the smart phones in the market.The handheld mobile terminal will have the function of a reader,point-to-point communication,and card emulation.The reading distance of ISO/IEC14443 A cards will be more than 6cm,ISO/IEC14443 B cards will be more than 6cm and the input return loss will be less than-18 dB.Secondly,the thesis introduces the overall framework of NFC technology,the operating principles of NFC antenna and the design methodology of impedance matching of antennas.Thirdly,the overall framework of the hardware of handheld mobile terminal with NFC function as well as its designing scheme is analyzed in detail,focusing on the NFC chips and the design of related circuits.Fourthly,an antenna model is established in the study via HFSS simulation software.The parameters affecting the antenna performance are simulated and their effects on the antenna performance are explored in detail.The designing parameters of antennas are determined through a comprehensive data analysis,thus accomplishing the production of antennas.The input impedance of the antennas is measured with a vector network analyzer.Finally,the circuit typology of NFC chips RF front-end is simplified.The design and simulation of impedance matching network parameters are accomplished with the help of Smith Chart.The performance of the antennas is improved through the adjustment of parameters;hence the design objective is finally achieved.The thesis ends with a conclusion of the design and the direction for future research.So far,the mass production of the handheld mobile terminal with NFC function designed in this thesis has been accomplished and the bulk shipment is on the way.It turns out that all the performance parameters have achieved their original design objectives.