| RFID (Radio Frequency Identification) can make use of radio frequency signal to identify and read a lable of the target to obtain the information of the target, acquiring the relevant data of the objects and recognizing objects by RF,it is a non-contact automatic Identification technology.Among them, because UHF RFID (UHF-RFID) has a far reading/writing distance, able to identify the fast moving objects and its several targets recognition characteristics,, make it taking great attention in the area of IOT (International of Things) and so on. But, the existing UHF-RFID tag antennas usually use the dipole substructure, which can basically satisfy the requirements of common applications, but to the special requirements (such as bandwidth requirements, dimensional requirements, metal environmental requirements, etc.) in the application, the impedance matching, radiation efficiency, direction characteristic graph will change, causing worse performances of the label working, and even cannot be used. In order to solve performance requirements for different occasions in the special applications, this thesis will be focused on the investigations of various new labels on the basis of UHF-RFID. All the work in this paper can be summarized as follows:(1) This paper first introduces the background of the researchess, describes the current research situation of the electronic tags and their development trend, analyzes the theory of RFID, as well as the design theory and optimization method and processing technology, etc. Given the reason of why new types of RFID tags should be designed.(2) In order to meet application purpose that RFID tags all can be used globally, this paper designs a kind of ultra-wideband electronic tag antenna which covers the RFID frequency bands of all countries and regions, using the method of combinating the straight line dipole sub-structure and closed dipole sub-structure, plus the electronic tag chip, constitute a new type of passive full frequency electronic tag. This paper will give detailed theoretical analysis, the chip’s introduction, and the simulation results.(3) In many applications, the labels need to stick attached to metal surface.In view of this demand, this paper puts forward a design of an anti-metal tag based on microstrip structure, combined with inserted feeding structure and grounding short line structure. Through the analysis of inserted feedingstructure and the grounding short line structure’s influences of the antenna, this paper gives the methods to improve the antenna’s performance, and then gives optimal simulation results. (4) No matter in what occasions, electronic tag’s using life and reading/writing distance are important indexs to measure the tag’s performance. In order to satisfy the requirements of the long distance and long life requirements, we develop the BAP tag (Battery-Assisted Passive Tag) based on the active and passive tag systems. This paper gives a detailed study of the system of the BAP based on an EM4235chip, the way of circuit connection, the equivalent circuit of the circuit, the performance analysis, the test results, and its appliication analysis.(5) Based on the research of this work, some future development of RFID and some suggestions are proposed... |
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