Design Of A UHF RFID Active TAG Based On EPC Gen2Protocol

In our country，techniques of RFID(Radio Frequency Identification) have beenapplied to highway automatic toll collection, e-ticket, motor-vehicle administration,monitoring animal and plant, merchandise anti-counterfeiting and so on. If tagcharacterized by far distance recognition, better compatibility, long service life andlow-cost, it will win the market and customers.In this thesis, a kind of active RFID (Radio Frequency Identification) tag designplan based on EPC Gen2protocol is presented to solve the problem of identificationdistance nearly and weak generality. The design plan is backed up by deeply analyzingthe EPC Gen2protocol and wireless communications theory.1．This is the RFID tag baseband program design and simulation. Basebandprogram, based on EPC Gen2protocol, is implemented on FPGA chip. It includes: PIEdecode module, CRC, command parser, pseudo random number generator, main state,storage, FM0and Miller encode module and data acquisition transfer rates controlmodule. Designing method of every module is presented and the simulation result isanalyzed in detail. With storage design optimization, FPGA logic resources can be saved.The example of Query command parsing is presented to illustrate how to designcommand parser. According to the requirements of EPC Gen2protocol, design methodof encoder, decoder and main state is presented. A FIFO is uesed to design the dataacquisition transfer rates control module in order to regulate the transmission speed. Atlast, the simulation result of the baseband program is analyzed in detail.2. This is the RFID tag hardware circuit design. Hardware circuit includes:backscattering modulation circuit, demodulation circuit and power circuit. Firstly, twoproposed approaches are extended to active tag modulation circuit. Two strategies arecompared, and the test results show that backscattering modulation circuit is suitable forthe active tag. Secondly, by theoretically analyzing, IQ demodulation circuit can solvethe problem of “fuzzy point”, then offering the design method of every module. Thirdly,power circuit design method is presented.3. This is the RFID tag antenna design. Firstly, a brief introduction to parameter which can affect antenna characteristics is provided. Then, the effect of inverted Fantenna structure on the antenna is discussed mainly. All simulation and modeling ofthe antenna is processed with HFSS12software.4. This is the RFID tag tests. Practical test waves and PC test results indicate thattag works well.