The Design Of RFID Reader In UHF Band

RFID is a new technology of non-contact automatic identification which booms up in recent several years. At the present time, both in theory and practice application aspects, it comes to the front more and more, in that UHF RFID technology is the most advanced in the world. UHF band RFID has advantages of long identification distance, speedy identification, relatively long life and so on which is applied to these domain electric street nameplate, freeway charge, Logistics Management and Strategy and tracking of products. In the future few years, the development of UHF RFID reader is perfect foreground, for the technology of RFID will be instead of bar code step by step and dominate in EPC.This paper in allusion to the research of UHF radio frequency identification system, engineering prototype development as the main line focus on the digital base band control systems and backscatter modulation of the RF systems development method. This paper selected the international standards ISO / IEC 18000-6C of the latest development, the most comprehensive agreement as the research object. Base band circuit portion adopts the ARM7 family processor as the main CPU, responsible for the scheduling and expands interfaces such as USB2.0, RS232/485 and Ethernet interfaces. Also, DSP chip TMS320VC5509A is selected for signal acquisition and processing, calculation, encoding, decoding, calibration, and other functions.The two processors connected with each other through FIFO circuit, so that the whole system can cooperate with each other steadily. The RF part introduces a zero IF receiver, It uses high-speed ADC and DAC on the acquisition and control signal, then achieves system software control by embedded C language and assembly language, and partially completes the operation of RF label instructions in the agreement.In addition, this paper also uses ADS which is the most widely used in RF System design in the engineering field, simulating high-frequency system to achieve the best performance of the system design. In the debugging process, we use vector network analyzer and digital logic analyzer systems, and other equipments on some strict tests to ensure the reliability of the system.The design of UHF RFID reader has the traits of steady-going, abundance of interfaces resource and so on. It is easy to make second development then be the same with special application system. Universal base band is very easy to connect to different RF system.