| RFID (Radio Frequency Identification) is an automatic identification technology,which uses radio frequency signals to achieve non-contact information transmission and to achieve the purpose of automatically identify the target object. With the combination of RFID technology and Internet, mobile communication technology and the rapid development of Internet of Things technology, there have been more and more different application scenarios for RFID technologies, and they put forward many needs to RFID technology, include the design of tag antennas, for example, tag antennas need to be smaller to adapt the application, they need to be resistant to metal, and they need to work properly when imbedded in the carriers mad of metal.The main work of this paper is the research and design of miniaturized tag antenna and the embedded scenes of tag antenna. The main work of the thesis includes the following parts:First of all, it briefly introduces the RFID technology and the development and application of tag antenna. Then, the development status of the subject at home and abroad are presented. Beginning from the basic parameters of antennas, the theoretical basis of the RFID tag antenna, the impedance matching technology of the tag antenna,the anti-metal technology of tag antenna and the miniaturization technology are reviewed and introduced.Second, two miniaturized RFID tag antennas were designed. One of them are designed according to the principle of curved flow, which is when increasing the current path on the antenna, the operating frequency can be reduced. double-layer media structure are used as the substrate, the size this tag antennas is 21mm×12mm×1.8mm,and can function well at 920MHz-925MHz. As for the second tag antenna, the ceramic material with high dielectric constant is used as substrate. The short-circuit-loading structure is used to achieve the miniaturization. By sweeping the parameters of the antenna, the final optimization model is presented. Then, the influence of the parameters such as the length and width of the metal flooring on the label was studied, and the antenna prototype was carried out and be test.For the study of embedded applications, the effect of embedding metal carrier on the performance of the antenna is studied. After finding that embedding will cause S11 deterioration and frequency offset, and after discussing its causes, a new embedded method is proposed and studied and the effects of carrier shape, size and method to embedding in metal carrier are studied. On this basis, a method to realize the management of surgical tools by using embedded tags is carried out and be test. |
