【摘要】 设计了一种基于MFRC522的读卡器,工作频率为13.56MHz,读取支持ISO14443A标准的射频卡片.给出系统硬件设计原理图,研究MFRC522发射电路中滤波、天线阻抗匹配和接收三部分电路元件值的确定方法.分析电路中电容元件的封装尺寸和材质对射频信号收发的影响,提出PCB天线的设计要求.阐述系统软件控制流程.捕捉并分析读卡器和射频卡之间收发信号的波形图.测试结果显示天线周围无金属物时的读卡距离最高可达60 mm,电路的稳定性和可重复性优良.更多还原

【Abstract】 A kind of RFID card reader which is based on MFRC522 and works on the frequency of13.56 MHz is designed.The reader can read RFID cards that support ISO14443 Astandard.The principle schematic of hardware design is given.The methods to determine the component values in circuits in the parts of radio-frequency filtering,antenna impedance matching and receiving are studied.The impacts of package size and material in the capacitive element in the circuit on the RF signal receiver are analyzed.The design requirements for PCB antenna are presented.The flow of control system software is described.The waveforms between the reader and RFID card are captured and analyzed.The experimental results show that the readable distance of reading card can be up to 60 mm with no metal around the antenna.The circuit is stable and repeatable.更多还原