The Design And Communication Of The UHF RFID Reader

The radio frequency identification technology is a kind of automatic identificationtechnology burgeoning since the 1980s. Radio frequency is used in the bidirectional noncontactdata communication. Compared with 13.56 MHz radio frequency identificationsystem which has been applied universally, 868MHz radio frequency identification system hasmore advantages as follows: farther distance of reading and writing, faster reading speed andso on. Therefore, in present 868MHz radio frequency identification system has become theinternational hotspot of RFID development.The following researches were investigated in this paper: the principle of the UHF RFIDelectronic tags and its characteristics, structure according to the ISO18000-6 standard as wellas the method of reading and writing.The study focused on the design scheme of the reader corresponding to the UHF RFIDelectronic tags including the hardware circuit of the reader and its software procedure designas well as communication implement with PC.In the process of the hardware designing, ATMEL Company's AVR MCU ATmega8 asthe main controller was selected in this paper and the circuits of the main control model, thereset model, and the communication model were established with it. Furthermore, the RFtransceiver module was designed through the RF transceiver chip (TRC101) developed by theRFM Corporation.The modularization and structured programming was utilized during the process of thesoftware designing such as the assembly language and Visual Basic for the MCU procedureand the PC serial communication respectively. The error rate of the designed software wasreduced greatly after tested and the preventing conflict function of the anti-collision procedurebased on random binary algorithm was achieved successfully.This design has the advantages of high reliability and modular design, etc. The validationexperiments indicated that the expected purpose was realized according to the standardrequirements and also proved that the design performance was stable and reliable.