Research And Design For Ultra Wideband Receiver Circuits And Mxer In Uwb Rfid System

UWB is a wireless technology capable of low power consumption and high data rate transmission based on ultra-short pulses without carrier signals. RFID is a communication technology designed for automatic non-contact identification, which exchanges data by radio frequency signals. RFID is widely used in logistics, security, automatic production lines, intelligent Internet of things, electronic payment and many other applications. UWB RFID system inherits the advantages of both the technologies, which has great potential for developments and applications. UWB RFID system can be achieved by IR-UWB and passive chipless RFID.Ultra wideband receiver is the key issue in the research of UWB RFID system, including coherent and non-coherent receivers. Their radio frequency receivers include a LNA (Low Noise Amplifier) which amplifies the received signals and a mixer which down-converts the amplified signals. LNA and mixer output baseband signals and ensure successful performance of receivers like sensitivity and linearity. The design for LNA and mixer circuits in UWB receivers has extremely important meaning for both theoretical researches and applications.A brief introduction to the UWB and RFID technology is given, includes the operating principle, classification and applications. The design methods of functional modules like LNA and mixer circuits in UWB RFID receivers is analyzed. The thesis includes following aspects. The operating principle of LNA and the wideband impedance matching concepts are discussed, based on which, a common-source with inductive-source feedback LNA working over2GHz band is designed, whose input and output impedance matching are better than-17.5dB and-10dB, respectively. The theory of mixer is derived based on small signal analysis method and even-odd mode analysis technology. A miniaturized single balanced passive mixer working over600MHz band is designed with discrete components, whose length and area are reduced to74.5%and54.0%of the traditional circuits’structure, respectively. An active Gilbert mixer based on CMOS is also designed and simulated, which can meet the basic requirements of UWB systems.