Biography
Enrollment Date: 2005
Graduation Date：2008
Degree：M.S.
Defense Date：2008.05.31
Advisors：Yongming Li Chun Zhang
Department：Institute of Microelectronics，Tsinghua University
Title of Dissertation/Thesis：Research and Implementation of UHF Low-Voltage Low-Power Passive RFID Transponder
Abstract:
Radio Frequency Identification (RFID) is a kind of contactless automatic identification technologies which identify individual items and exchanges data between a reader and a transponder (RFID tag) based on electromagnetic coupling. Because of the merits of RFID system itself and the rapid development of integrated circuit technology, RFID is more and more widely used in various aspects of human life, for example supply chain management, transportation control, electrical tickets and so on. Due to the advantages of long working distance, small size, low cost and its’ huge marketing value, UHF (Ultra High Frequency) passive RFID tag has become hotspot of this field nowadays both in domestic and overseas.
Firstly，the paper gives a brief introduction of the working principle of passive UHF RFID systems is described firstly. RFID in essence is a kind of short distance wireless communication. As about passive RFID energy recovery is also a critical problem. From the aspects of power recovery and dissipation, antenna suitable for RFID transponder and matching technology between antenna and chips, this part talks about the direction of promoting the performance of RFID tags.
Secondly, the paper introduces the protocol of ISO18000-6 type C and analysis the communication type and related parameters. The system construction and interface of the several part of the whole tag are also given.
The most important work of this paper is about the low power analog front-end circuits design methodology of UHF RFID tags. How to promote the power efficiency of AC-DC converter, how to decrease the leakage current of regulator in the low power providing mode, how to promote the PSRR of voltage and current reference, how to eliminate the static power consumption of POR circuit, how to extract communication data from low modulation index ASK signal, how to stable the frequency of open loop frequency generator against power changes and its low voltage, low power design, are all discussed in this part. The whole tag chips with digital circuits are designed and implemented in HJTC 0.18μm CMOS technology.
The finial part of this paper discusses the UHF RFID tags test method, including wire and wireless test. The test skills of differerent modual are exploited. At last the test results are given.