UHF RFID Reader Antenna Optimum Design And Simulation

Interest in the radio frequency identification (RFID) technology has grown exponentially in the past few years. RFID technology is a non-contact identification technology, it relies on the reader and tag coupling to transmit information, without human intervention, automatically work in a variety of harsh environment. Therefore, with its unique advantages, RFID technologies become a research focus.First, this paper briefly analyzes the basic principles of RFID technology and RFID system typical structure, and focusing on the principles of the reader antenna. Second, make a detailed analysis of the theory of microstrip antennas, including the typical structure of the microstrip antenna, the advantages and the disadvantages, radiation theory and design methods. On the basis of these, research and design the RFID reader antenna which used in the electronic toll collection system (ETC).Then, This paper introduces a ultrahigh frequency circularly polarized (CP) rectangular microstrip antenna on air substrate. The antenna inserts four same slots on the microstrip patch and a small slot on the center of the patch, which could reduce the size of the patch and have the circular polarization operation. Further studies on its circularly polarized performance impact of antenna parameters, followed optimizing the antenna parameters, experimental results show that good CP radiation performances.Finally, this paper, based on the analysis of a single-fed circularly polarized microstrip antenna theory, designs a new type of single-fed ultra-high frequency RFID reader antenna, which uses relative to the current widespread adoption of symmetrical isosceles triangle Cutaway easier processing of non-symmetric rectangular cutting angle to achieve the circular polarization. The antennas were selected polymer organic magnetic materials and Rogers TMM4 on substrate. Polymer organic magnetic materials can reduce the antenna size significantly, and light weight. But it was low gain and expensive. Although the antenna is big on Rogers TMM4 substrate, but the gain was fine. Two antennas were simulated and optimized by HFSS, and received better circularly polarized performance.