The Research Of Key Techniques Of RFID Reader Front End

In the field of wireless communication,The RFID technology as an RF signal through the use of spatial coupling(alternating magnetic or electromagnetic fields) to achieve non-contact transmission of information and the target object recognition technology,is widely regarded as one of promising emerging technologies of the century.Currently Existing RFID reader on the market has a long product cycles,high power consumption,a short identification distance and other problems.It does not well meet application needs. The purpose of this study is to design and simulate a high-performance reader with a lower power consumption,and improve the power gain and the label identification distance.The main work is as follows:Firstly,Through the study of RF communication protocol of ISO18000-6C/B,the key critical circuit design scheme of RF transceiver module is presented by using the low-power consumption and low BOM radio frequency integrated chip AS3992 producted by microelectronics company and its peripheral interface as the foundation.The loop filter,balun transformer,power amplifier,coupler and the impedance matching network circuit which is adapted to whole circuit are designed.The mimimum system of MCU is completed and its' overall design is comleted too.The schematic design of RF circuits is finished by using Altium Designer software.Secondly,The RF transceiver circuit of the reader is analysed.The RF receiving and transmitting system are respectively simulated by Advanced Design System software through the actual integrated RF module.Verify the RF transceiver channel characteristics of the program. Then the analysis of the transmission of radio frequency carrier signal is finished.The transient simulation,phase noise simulation,band selective simulation,channel simulation, down conversion simulation, integrated power gain simulation and the S parameter simulation is designed by ADS software.The simulation results show that the design of the amplifier has a system gain of 49.6dB and a good input/output reflection coefficients and isolation.The RF circuit which meets the performance index is in accordance with the actual requirements of wireless communication system.