Design And Implementation Of Transceiver Front-end For UHF RFID Localization System

With the continuous development of science and technology,radio frequency identification technology(RFID),which is one of the key technologies of the Internet of Things,has been widely used in intelligent transportation,warehouse manageme nt,logistics supply and other fields,it has important research significance.RFID technology has the characteristics of fast signal reading speed and strong anti-interference ability.By interacting with the information carried by electronic tags,it realizes non-contact automatic identification and has good performance in indoor positioning.Ultra-High Frequency(UHF)RFID system has advantages such as longer working distances and multi-tag identification,and have become research hotspots in recent years.However,the current RFID readers on the market have a narrow working bandwidth and do not meet the requirements of carrier phase positioning systems.Therefore,a UHF RFID radio frequency front-end circuit is designed and implemented in this thesis,which can achieve fast jumps within a wide operating bandwidth.Frequency,the main research content of the thesis is as follows:First,the basic principles of RFID system structure and carrier phase positioning are analyzed.According to the functional requirements and application scenarios,various performance indicators and overall design schemes of the RF transceiver front-end are determined.The receiving and transmitting links adopt a direct frequency conversion structure and use the same local oscillator source,so as to achieve the purpose of receiving and transmitting synchronization.The receiving end can directly obtain the original I/Q data after demodulation and down conversion.Completed the analysis of key technica l indicators,main chip selection and feasibility analysis of each module.Then,the UHF RFID radio frequency front-end circuit design and implementa t io n are implemented.The transmitter completes the modulation,up-conversion,filtering and power amplification of the baseband signal,and the receiver completes the demodulat io n of the reflected signal down-conversion,filtering and power adjustment.The system mainly includes a control module,a clock module,a power module,a transmitting module,and a receiving module.The overall circuit is controlled using an FPGA chip.Complete the simulation verification and circuit diagram design of some components and functio ns of each module,then complete the PCB design and production according to the circuit diagram,including the laminated structure,impedance matching,layout,wiring and so on,the precautions of RF circuit board production are analyzed.Finally,the UHF RFID radio frequency transceiver front-end is actual y tested,the control module,clock module,power module,transmitting module,and receiving module are independently tested to ensure that each module works normally,and the overall system test is completed.The test results show that: The design scheme basically meets the design requirements of UHF RFID radio frequency front-end.