Design Of UHF RFID Reader Antenna Based On The Leaking Field Of Transmission Line

RFID(Radio Frequency Identification), as a kind of un-touched technology, is able to collect information in a fast, accurate and real-time way. And it is widely used in the fields of physical distribution, traffic management and retail industry. In order to realize the exchange of date and information, the antenna products and antenna theory are applied in the RFID application inevitably. There appears many occasions that require the antenna to ensure the quality in the near field, such as the management of file cabinet, monitor of precious metal and industry of garment retail. Thus, the topic, which aims to ensure the antennas’ stability, and not to misread, not to omit reading and not to cross read, is a new task of near-field RFID reader antenna.Based on these needs, this paper takes advantage of the leakage electromagnetic wave produced by the process of transmission line. First, the antenna model is simulated by Ansoft HFSS software. Second, the model is optimized based on the needs and index. Third, the object is manufactured through model. Fourth, system test is processed with RFID reader and tags. Through the steps above, a serious of reader antennas which are appropriate for UHF RFID are designed and meet the needs of different situations。The first is the near-field antenna used in the file cabinet, which is for the monitor of the files. The second is the near-field antenna for handset which is used to search the file. The simulation and the test data of the antennas is given in this paper. Both of them satisfy the request of different application environments through the test based on the real simulated environments.The characters of this kind of antenna are below. 1. The principle of the designing is simple. 2. It has relatively targeted reading distance and uniformity in the near field. 3. It is able to change its length depending on applied situation. Through the research of UHF RFID near-field reader antenna, this paper gives out the steps of the design of antennas attached with optimizing methods and testing data. The detailed test reports are also presented after the objects based on different test environment.