The Design And Realization Of RF Front End Of Passive UHF RFID Tags Chip

Radio Frequency Identification (RFID) is an automatic identification technology with using the data storage and remote reading of data to achieve the identification process. For its long-distance, high speed and low-cost, Passive UHF RFID technology has become a hot topic in the RFID technology, and will be a basic technology in the future information society construction. Currently, RF front-end circuits with the low-power consumption and low-cost have launched a large number of studies for the applications of RFID chips.First, the paper makes the analyzes of the radio frequency identification system and the physical basis of its work link with the basic theory of magnetic field and describes the physical processes of the energy of radio frequency, such as data transmission and energy transmission.Secondly, this paper has made the instructions of the overall structure about the UHF RFID tags, and analysis the circuit design specification of the RF front-end modules.Then, the paper elaborates the design principles of RF front-end circuit, including high efficient rectifier, modulation circuit, demodulation circuit and ESD protection. For the requirements of low-cost, this paper designed a rectifier with standard CMOS process and its efficacy reaches 60%~80%. At the same time, we improve the modulation and demodulation circuits, so that the sensitivity meets the protocol standards. As well, for ensure chip reliability, the paper designs an ESD protection for the antenna interface PAD. It can ensure the chip long-term effective work without impacting the performance of the chips.Finally, the paper introduces the entire chip layout design and some principles, and gives the relevant test methods and data.The chip putted in this paper has been taped out in January 2009 under the TSMC 0.18μm process line and proved to be successful, with the working distance up to 6m; the second design results taped again in July 2009 under the TSMC 0.18μm process line and the test results meet the wireless reading and writing MTP.