Arm9-based Uhf Reader Module Designed

Radio Frequency Identification (RFID) is the fastest growing non-contact automatic identification technology, both in theory and in practice is very satisfactory in recent several years. In particular, UHF(Ultra High Frequency)RFID technology has advantages of long identification distance, speedy identification, multi-tag identification capability, and so on , which is widely used in highway toll collection, logistics management, tracking supply of meat food safety, attendance access management and confidential documents management.However, UHF reader's development in China is at the initial stage, it exists problems in power consumption, low efficiency and high cost features on RF circuit design. The hardware interface and software API functions in readers are not be compatible sets of specifications. And the same products in different manufactures, even the same interfaces are also not interoperable, resulting in difficulty of many of the same product software development.In this dissertation, in order to solve above issues, ARM9-based UHF reader module is designed and finished, including all modules such as power supply design, the microprocessor, reader RF front end design, their devices parameters, the reader software design and system software.The main contents are:(1) Illustrates the background of the radio frequency identification technology and significance of topics, summarize an overview of RFID technology development at domestic and abroad, introduces the RFID system components and its working principle and its related standards. On this basis, explains for the weakness of the existing system, brings up the scenario of design ARM9-based UHF reader module.(2) In hardware, Microprocessor S3C2410A, which the highest operating frequency is 533MHz, core is ARM920T, is applied as UHF reader controller. Many rich external interfaces: USB, network interface, serial port, IDE interface, SD card interface and touch screens, are designed. The digital frequency synthesizer SI4133 is applied in sending circuit of RF circuits; Frequency hopping and pseudo-random frequency hopping sequence is devised in software in order to avoid working with the band when other devices interfere with the environment, and in order to improve the hitting rate of reading and writing tags. To meet the EPC GEN2 standard radio frequency modulation circuitry, power amplifier, power setting circuit, RF power management circuit, RF receiver circuit are devised by selecting the appropriate radio frequency chips, and demodulation circuit are also devised by picking up the appropriate high-frequency detector diode; return information signal from tag, and its amplification circuit, base band signal generation circuitry which return from tag are designed.(3) According to the EPC GEN2 standard, the reader software has been developed. Sending commands with the pulse interval encode to the tag is prepared. The program of generating CRC5, CRC16 check code is devised. Decoding the return information from tag by adopting the timer capture broadband pulse is finished. Bootloader, embedded Linux operating system kernel, graphical user interface library with Qtopia root file system customization and design are finished. The driver development process is designed, and a demonstration of the UHF readers'layout is given.(4) The reader sending various command signals and the base band signals after processing of receiving information from the tag are debugged. The characteristics of read and write tag of reader module are also measured. After downloading the entire system, the embedded Linux and the external interface drivers are debugged.After debugging the system, readers setting the power, reading and writing tags and the system peripherals interfaces all work well. The whole design goals are reached.