The Design Of RF Front-end For 13.56MHz RFID Tag

Radio frequency identification (RFID) is a contactless automatic identification technology. RFID is popular in logistics, retail, public transportation, attendance system, national defense and other fields. RF front-end as an important part of RFID tag chip takes the function of modem, power supply, clock extraction. It largely determines the performance of RFID tags. Now some RF front-ends don't have enough demodulation capability. Because of this, the passive RFID system can't support high speed data transmission.In this paper, a design of 13.56 MHz RFID RF front-end is presented. The functions of modem, power, and clock extraction are achieved. To simulate the RF front-end circuit, the RFID system model is established which is based on the analysis of communication between the reader and tag. All the modules of RF front-end are introduced, and their schematic and simulation results are given. This pager focuses on the demodulator. On the basis of the traditional envelope detection scheme, this paper makes some improvements and a regulating circuit is added to the demodulator to improve the stability. In spite of the additional power consumption, the RF front-end now supports high speed data transmission. Finally the layout is designed with Virtuoso and the test report of the chip is given.The test results show that the design of RF front-end complies with the design requirements. The RF front-end can cover 1.5 A/m-7.5 A/m working field. It's able to provide 13.56MHz clock signal, supply power and support 106,212,424,848Kbps data transmission. The power consumption of the RF front-end is about 395.1?W. This RF front-end is used in passive RFID tag chip, which can be used in finance, security and other fields. This design can be a good reference for other designers.