Research And Design Of Tag Antenna

Radio Frequency identification is considered as one of the important ten technologies in the 21th century, which is based on the fact that it is quick, real-time, exactly collecting and processing data. This technology has good future in production, re-tail, inventory management and so on.The rapid development of RFID technology has set new demands on antennas.such as miniaturization of tag antenna and multiband of reader antenna.It is well known that passive tag consist of microchip and antenna. To achieve longer read rang, It is necessary that max power is transported from antenna to chip. So, based on these, the band of tag is analysed from this view that impedance matching between chip and antenna. The paper shows the key factor that affects the band of tag. Finally, the result is affired by test.Besides, Meander, Inductively coupled loop and Fractal technology are applied in order to miniaturization in this paper. For meandering technology, the key factors of meander technology is analysed by simulation and test. The result is important for antenna engineers. For inductively coupled loop, the technology is researched from equivalent circuit. The result shows that the real part and image part of antenna impedence can be adjusted respectively.Finally, many kinds of tags based on fractal technology are designed in this paper. The antenna size is smaller than traditional antennas. Besides, in this paper we try to design tag antenna based on two kinds of fractal curves, koch curve and Vee curve. Tag characteristic in different condition is researched. Based on these results, many tags are designed. The result of test shows that tags characteristic meet the requirement of design.