Uhf Band Rfid Reader Antenna Research And Design

Radio Frequency Identification is a non-contact automatic identification technology. In order to achieve the non-contact bidirectional communication between the reader and the tags, RFID achieved automatically to identify objects and obtain relevant data with wireless radio frequency signal. Compared with other identification methods, RFID has many advantages, such as strong anti-interference capability, without human invention, fast reading and writing, high identification accuracy. RFID technology has been developed fast and widely used with the world-wide attention and investment of Internet of Things within recent years. RFID reader antenna has played an important role in the entire radio frequency identification system as the transmitting and receiving identification signal facilities. So it has profound significance to research RFID reader antenna.This paper firstly introduced the components of the RFID system and how it works, etc. And then it did a detail work on the basic theory of antenna, introduced some basic theory and the development tendency of the micro-strip antenna.This paper based on the research of the design methods of the reader antenna, proposed a broadband external circularly polarized reader antenna which is applied to warehouse management. This proposed antenna used the structure of circular patch which fed by a3dB branch directional coupler to achieve circular polarized, and adding open stub at the feeding end of coupler to achieve wideband impendence matching by adjust the antenna impendence. In addition, based on the above design, the proposed antenna achieved wide-angle, wideband circularly polarized for the wide reading and writing range to accommodate the demand of some RFID system in the UHF band. Further, the article also proposed an antenna array based on the antenna above, the antenna array are arranged by three circular polarization element antenna, and the gain value with respect to a single antenna has improved greatly, the reading distance have been increased.