| Radio Frequency Identification is the technology that achieves non-contact information transmission using space coupling of electromagnetic waves and achieves identification purposes through the transmission of information. UHF-RFID has some advantages, such as long-range identification, rapid transmission, high reliability and high life expectancy etc.ISO/IEC18000-6C protocol is one of the most popular protocols in UHF passive RFID. It has absorbed the newest achievements of other protocols, so it has the best performance and been widely applied. In the article,920-925MHz frequency band RFID reader RF circuit and antenna are designed base on ISO/IEC18000-6C. The main jobs of the work are described below.1、The article briefly expatiates the composition and working principle of RFID system, analysis the main characteristics of ISO/IEC18000-6C standard, and compared with other stands, deduces the formula for calculating the communication link between the RFID tag and reader, provides a theoretical guidance for the reader circuit design.2、The article analyses the key technologies of transceiver channel, including SSB-ASK、DSB-ASK and PR-ASK modulation simulate、the relationship between modulation depth and the spectrum、the isolation technology of transmitter and receiver、Zero-IF quadrature demodulation technology.3、In the actual design phase, appropriate chip are choose through the analysis, and the circuit is designed.4、Base on the requirements of RFID system’s antenna, a novel UHF circularly polarized mocrostrip antenna used in RFID reader was designed. Through simulation and testing, the VSWR of this antenna is below1.5, Axial ratio is below3dB and gain is about5.1dBi in920～925MHz. |
PDF Full Text Request