Study Of HF RFID Reader System

Radio frequency identification (RFID) is one technology of automaticIdentification, which is used with the coupling of electromagnetic field to realizecontactless communication. it can identify the target and get the relevant data. Becauseof its strong ability to read and write，carrying a large amount of data and longidentification distance, RFID technology has been widely used in the field of datacollection and processing fast, such as cargo management, vehicle management, thecontrolment of access and so on. RFID card reader is key component of entire RFIDsystem, the success in the design is directly related to the performance of the entireRFID system.According to transmission protocols, the relative electromagnetic, communicationstheory and technology are analysed. The paper introduces design of the RFID cardreader and its modulation with carrier frequency of13.56MHz. Reader is based onMifare one card in line with International Standard ISO/IEC14443A. In the hardwarecircuit part, C8051F020microcontroller and MF RC500radio frequency station chipare pivotal components of RFID reader, hardware circuits are consist of microcontrollercontrol module, Radio frequency module, communication module. The reader antennaand capacitance matching circuit are designed with principle of series resonance. Thering antenna is printed on the circuit board and matching circuit belongs to the type of L.In the software part, software designs are consist of system initialization, radiofrequency identification module configuration, radio frequency identification moduleoperations on Mifare one card. The operations contain selection,anticollision, passwordauthentication and reading message. Finally, the reader can be fabricated, theperformances of the RFID card reader are tested and results show that system can workwell, and work distance can reach about7centimeters.