Research Of Some Key Technonlogies In RFID Systems

RFID as a new technology covers not only radio frequency technology but also cryptography, communication fundamentals and semiconductor integrated circuit technologies, which has a broad application foreground and commercial values. RFID has a fast development and extensive application aboard, while it just start to develop in China. This paper does research on a RFID system from practical aspect so as to meet the requirements of information acquirement and process in a fast and security way.Firstly, this paper analyzes current background and trend of RFID technology in and outside China, and describes its huge commercial profit and wide application value. Secondly, this paper illustrates RFID system's components, sorts, working mechanism and related feature and then explains the basic theory of data transmission, especially the principle of encode and decode ,modulation and demodulation .Finally, this paper proposes a method to design a long distance RFID system with passive no power tag.This paper mainly does research on circuit design of Target and Tag, and based on that it provide the target's circuit diagram and analyze the experiment result, and introduce the process and idea of the design; The paper design the Tag system including analogue and digital subsystem and provide the detailed circuit diagram respectively , and devise a new method to fulfill Tag 's controlling function; The paper propose a communication protocol in Host-target-Tag system and security mechanism in RFID system. On basis of the hardware system the paper designs, it devises an anti-collision method that is able to solve problems when communication among multi tags.The paper designs a RFID system with the feature: long distance communication capacity, fast solving anti-collision ability, and low power comsumption.Besides, the system is easy to implement and wothy of research.