The Technical Research Of UHF RFID Based On EPC Gen2 Protocol

The research and development on UHF RFID reader and tag are driven by the requirements in application of UHF RFID systems in recent years. The UHF RFID reader and anti-collision arithmetic are researched in this paper, which frequency is 860-960MHz.At first, this paper introduces the characters of EPC Gen2 standard, including encode, modulation and management of tags. It makes sense of the instruction for the UHF RFID reader's design.Secondly, the architecture of reader front end is determined based on the analysis of RFID protocols and wireless frequency regulations. Both of the transmitter and the receiver are on direct conversion architectures with IQ branches. The architecture is flexible for multi-modulation types, and upgradeable. The out band spurious spectrum is limited by raised cosine filter in transmitter, and the shadow effect can be removed by combining the signal power of two branches in receiver.Thirdly, most of the effects in the front end of reader are analyzed systemically. The model of RFID are built based on the research of theory, then simulate the transmitter and test the result of experiment.Finally, the anti-collision arithmetic of EPC Gen2 standard is researched. The anti-collision arithmetic of EPC Gen2 is based on slotted Aloha. Through simulate and test, there is a result that the setting of C and Qfp will effect the results of the experiments when the numbers of tags participated in query circle is over 50 or less 50.