Implementation Of RFID Reader In UHF Band

Radio frequency identification technology (RFID) is extremely rapid development in recent years as a non-contact automatic identification technology, ultra-high frequency (UHF) of RFID technology has characteristics like to identify long distance, to identify fast, long-life characteristics so that widely used on electronic road signs, highway fees, logistics management, product tracking and other fields. Therefore, the UHF band of the reader has a very good development prospect.In this paper, research deeply in UHF RFID systems , analysis of the reader's overall framework, select the receiver of demodulation program, determine the front-end radio frequency receiver and using ADS simulation Software to simulate the characteristics of mixer and analysis of the RFID backscatter principle analysis and simulation.In transmitters hardware design part, design the baseband DAC conversion circuit, orthogonal modulation circuit, achieved on the base-band signal modulation; design the transmitted power control circuits to command RF frequency power. In the part of the receiver hardware design, design the ADC pre-amplifier, ADC circuit, using a programmable gain amplifier to achieve the receiver automatic gain control.Reader through the B/S (Browser / Server) mode access Internet, design the web page, by visiting the Web server configure the reader. Achieve the main software system in the two processors: ARM7 family processor LPC2292 and DSP processor TMS320VC5509A. ARM processor as the CPU, receive the users order and feedback to the user; At the same time, expande the Ethernet, USB, serial interfaces, can achieve diversification expansion. In DSP, achieve the ISO18000-6B protocol, and the realization of the AGC receiver automatic gain control algorithms. In addition that, also deeply research the anti-collision algorithm, and make some improvements. The two processors are connected through the FIFO Circuit so that the whole system can coordinates stably work. Use of spectrum analyzer and digital logic analyzer to debug system,ascertain the reliability of the system.In this paper, the UHF RFID reader interface is rich in resources, it will be convenient for the secondary development system to make it applicable to the specific RFID applications. The common hardware platform and a wealth of resources to facilitate the expansion of multi-protocol.