Design And Research On Uhf Rfid Tag Antenna

RFID (Radio Frequency Identification, RFID) is a kind of automatic Identification technology, which is identified through radio waves, and the RFID technology is a new area that can be applied to the entire frequency band. As an important part of the RFID system, the tag antenna needs a further study and more performance optimization, which has been the important issue in the present study about the related research of the tag antenna. And a further study of the size problem of the tag antenna is one of the difficulties. In order to be more widely used in all walks of life, the anti-metal technique of the tag antenna also needs a further analysis.The research of this paper is all based on the analysis and design of ultra-high frequency band of the RFID tag antenna. Based on the project background and the research status at home and abroad, this paper firstly introduces some basic theory of the RFID system, including the working process and the composition of the RFID system, and the basic knowledge of the tag antenna. Then the radiation performance of the basic oscillator is studied and some properties of the antenna parameters are presented also. And then introduces the most important electromagnetic simulation software HFSS, which is used in this article. Analyses the related matching theory also, including the reading distance, the matching ways, etc.Based on the above basic knowledge and the key points of the analysis, this paper put forward two types of miniaturization tag antenna. The first one is a miniaturization tag antenna with the meander-line structure. The size of the antenna is only19mmx30mmx1.5mm, and the simulation gain reached1.48dBi, the radiation efficiency reached88.8%. The size of the miniaturization tag antenna with the SRR (Split Ring Resonator) structure is just24mmx25mmx1mm, the simulation gain is0.43dBi, the radiation efficiency reached94%. These two paragraphs of miniaturization tag antennas all use the simple T matching structure, and their size and gain all have advantages during the present research about the miniaturization of tag antenna. And these two paragraphs of miniaturization tag antennas all have the merits of simple structure, low cost, easy to manufacture, etc. Finally, the meander-line structure miniaturization tag antenna is processed and manufactured, and the impedance performance is carried on the test by the vector network analyzer and the special probe. The result of test and simulation are analyzed and the contrast figures are made, these results prove the availability and practicability of the miniaturization meander-line structure tag antenna. At the same time, this paper analyzes the influence of metal on the performance of the ordinary tag antenna. Base on the analysis, a fall F type of miniaturization anti-metal tag antenna is designed. This anti-metal tag antenna not only meet the characteristics of anti-metal environment, but the size is only29mmx36mm, the simulation gain is-4.4dBi. During the designs of anti-metal tag antenna, the size of this anti-metal antenna also held a lot of advantages. At the same time, this article also analyses the performance and the changes of the impedance with the variation of sensitive structure parameters of the anti-metal tag antenna.