Research And Design Of RFID Tag Antenna Technology Based On Applications Of The Internet Of Things

Radio frequency identification (RFID) technology is a kind of wireless communications technology which exploits radio signal to achieve automatic target recognition. The technology allows not only storing a relatively large amount of information about the target, but also changing and processing information." Internet of Things" is aimed to construct a network to connect everything in the world, based on the Internet of TCP/IP. International Telecommunication Union (ITU) reports that the ubiquitous "Internet of Things" communication era is approaching, indicating that the key RFID technology of which will enjoy its rapid development.In this paper, the design technology and optimization algorithms of the tag with chip will be firstly researched. Based on the study of the equivalent circuit of tag antenna and a summary of various optimization algorithms, an UHF band isotropic tag antenna whose impedance is tunable to match with different chips is proposed. The size of the tag antenna after optimization is101.8mm x22.3mm, whose structure is characterized by:tag antenna consists of two dipoles and a Π-type matching network. The simulation results in HFSS14.0are:-10dB impedance bandwidth of840MHz-930MHz, covering North America, Singapore and the European UHF frequency band and gain at the center frequency of915MHz is2.45dBi, which is stable within the effective frequency range. According to the actual needs of the subject project, this paper proposed threetag designs, whose application scenarios are tobacco cartons, glass bottles and special shape applications. The test results of these three physical modelshave reached good agreement with thesimulation results using the software of HFSS14.0.Another research emphasis of this paper is the design and measurement technology of the chip-less tag, for the reason that miniaturization and low-cost technology has become an inevitable trend of the development process of the RFID system. The proposed design of chip-less RFID tag is based on multi-helical filter stop band, utilizing the spectral characteristics of the coded response signal. The RFID system consists of four parts:a transmitter, a reader antenna, chip-less RFID tag and receiver, whose effective working frequency ranges from3.3GHz to4.7GHz. Use Anritsu MS2026Network Analyzer to test the system, position of the notch frequency is nearly consistent with the simulation results.