Ultra-wideband Antenna And Chipless Tag Design For RFID System

Radio frequency identification(RFID)is a kind of wireless communication technology which gets target information through radio frequency signals.It has the advantages of large capacity,low cost,long life and repeatability.RFID system can be used to achieve the 'goal of global tracking and sharing of article characteristics with Internet Technologies.In line with the rapid development of technology,the application domain of this method is getting larger and larger.And this technology has become a hot field of current research.It has more and more extensive application prospects.The cost of RFID tags is a bottleneck in the development of RFID technology.The existing chipless tags have many defects such as low coding capacity,poor recognition accuracy,short recognition distance,and too high requirements for readers.Based on the chipless tags encoded in frequency domain,this paper designed miniaturized chipless tags with anti-deflection ability and remote identification ablility,which enhance the ability of chipless tags in complex environments.The chipless tag based on frequency domain coding consists of filter structure and receiving antenna.In this paper,based on the research of helical filtering structure,parallel open branch filtering structure and DMS structure,two new filtering structures has been designed which working in 3GHz to 4.5GHz.At the same time,the resonant depth of resonance point is increased.The monopole disk antenna is optimized and a new monopole omnidirectional antenna is designed which works in 3GHz-10GHz.It was designed to increase the resistance to deflection.A vivaldi high gain antenna is designed which works in 3GHz-10GHz.It can increase the distance of recognition.Through different combinations of antenna and filter structure,4 4-bit chipless tags were designed which work in 3GHz-4.5GHz.Through a large number of tests,the anti-deflection chipless tags can achieve good identification at 300 deflection.The remote identification tag can achieve good identification at 40cm distance,which is in good agreement with the simulation results.All of the results were tested in anechoic chamber with the vector network analyzer.