Passive Rfid Antennas Based On Microstrip Line Feed

Radio Frequency Identification (RFID) is gradually developed into an interdisciplinary technique. It integrates many different techniques together, such as microwave technique, EMC, semiconductor technique, data protection and cryptography, telecommunication technique, manufacturing technique etc. RFID antenna is one of the key techniques of RFID system, and is becoming an important research direction. Based on the research of available RFID antennas, this thesis proposed a new kind of RFID antenna. The new kind antenna is analyzed by Moment method. Meanwhile, the antenna is fabricated and tested. The measured results show a good performance of this new kind antenna.The main work and the creative parts of this thesis are summarized as following:1. The developments of the RFID system and RFID antennas are summarized. The different configurations of the RFID antennas and the advantages and disadvantages of different type antennas are analyzed. The application and the developing trend of the RFID antenna are introduced.2. The selection of the configuration parameters of the wide band RFID antenna fed by microstrip is studied. The influences of the antenna configuration parameters and the materials of the substrate on the antenna performance are studied. The influence of the mesh size on the calculation accuracy is also analyzed. The results show that too high or too low dielectric constant of the substrate, too thick or too thin of the substrate size can affect the antenna performance obviously.3. A new kind of RFID antenna which has properties as fractal antenna is proposed. Moment method is used in the analysis of this new kind antenna. The parameters, such as input impedance, return loss, radiation pattern are analyzed. The antenna is then fabricated and tested. The results show that the proposed antenna has good performance, and can be used in RFID system. antenna; Fractal antenna...