Research And Design Of Portable RFID Reader Based On UHF

RFID is a Non-contact automatic identification technique based on the coupling of electromagnetic wave or the reflection principle. It will construct the Internet of things, which connects the logistics and information flow, with combine of the computer communication technology. The wide applications of the Internet of things provide an important and technical resource for the economic recovery of global and reduce the cost of the global supply chain greatly. So it has attracted a great deal of interest in many countries. The first element for constructing the Internet of things is the size of scale which means that the lower cost tags and readers, and the second element is the front-end acquisition device having the long-distance and multi-objective recognition ability. Owing to its advantages such as low cost, Antenna of small size, confidentiality strong and long recognition distance, the UHF RFID system, which is based on passive tag and form the front-end of the Internet of things, is regarded as the most ideal technique for replacing the Bar code.The further development of RFID technique is depending on the break through of some key technologies. The speed development of large scale integrated circuit makes it be a possible for designing a portable reader which is low cost and low power consumption in recent years. As a core of the UHF RFID system, reader is a bond to relate the lots of RFID tags and upper application program. In present work, we choose a ARM9 chip as a core and embedded WinCE system as upper computer, which can provide touch screen control mode. The reader can reduce the power consumption by using power management modules. By installing the small flat microstrip antennas, the reader could work independently with the energy of Li battery.The work is structured as follows. In chapter 1, the kinds of RFID technique is carried out, and its advantages and current situation also are introduced. We are focused on analyzing the EPC Class1 GEN2 protocol which is employed in portable RFID reader base on UHF in chapter 2.In chapter 3, the total system framework of portable RFID reader is presented based on the fundamental knowledge of chapters 1 and 2 have been given and furthermore, as the order of vibration module, RF module, power management module, principal computer module and small microstrip flat antenna, we design the hardware of reader. The software structure has been introduced in chapter 4 and thereby we describe the method of realization of software for control flow. The discussions of debug and test for reader is carried out and some questions we have suffered also been analyzed in chapter 5. The conclusion for the thesis and the future for the field of UHF RFID are presented in the last chapter 6.