5.8GHz Portable RFID Reader RF Front-end Design

Electronic Toll Collection (ETC) technology is an emerging technology for road vehicles fast charge. It can complete vehicle identification and chargeback operation in the case of non-stop, and can improve the efficiency of road traffic. With the continuous growth of urban vehicles, ETC technology is also expanding the scope of application. However, on the one hand the standard ETC reader fully functional but structurally complex, expensive, difficult to promote for the general market. On the other hand, urban traffic management work is still heavily dependent on artificial manner. Market urgent need for a low cost, easy to use, adapt temporarily erected portable ETC reader.In this thesis, the front-end of 5.8GHz portable RFID reader that is used in ETC system is researched. Thesis described the RF front-end design principle and composition, and analyzed indicators. The frequency source, modulation and demodulation module, amplifiers, microstrip antennas are analyzed in theory, introduced the design and application of the results. Among them, the frequency source and modulation/demodulation module were designed by two kinds of special technical solutions. Oneis designed by discrete devices, and another is designed by specific integrated chip. In the discrete solutions, using a phase-locked loop technology to achieve emission carrier generation, focusing on the single-chip PLL chip ADF4106 were introduced, and the use of simulation tools for phase-locked loop circuit simulation. In specific integrated chip solution, BK5822 was introduced, and was discussed its transmit and receive channels working principle and use of results, as well as the difference between discrete devices solutions. In amplifier design focuses on the principles of the amplifier characteristics and linearity, stability, design methods, and the realization of the amplifier are described. In the part of the antenna design, mainly for circularly polarized microstrip antenna design and antenna theory describes the simulation design. Using simulation tools, greatly improved the efficiency and effectiveness of the designThrough research, the front-end of reader reaches a predetermined technical indicators, and have a high degree of integration, miniaturization and low cost,has practical value.