Research And Design Of UHF RFID Single-Chip Transceiver Based On CMOS Technology

Radio frequency identification is a type of non-contact automatic identification technology which exchanges data and energy between readers and tags by wireless electromagnetic signals.The rise of the internet of things pushes the development of wireless communication system,among which UHF RFID technology stands out and pushes the application of the readers.The low cost and monolithic UHF RFID reader has been a popular research topic with the development of CMOS process and the wide application of RFID technology.According to the protocol of ISO/IEC 18000-6C,a monolithic UHF RFID transceiver is designed,in a standard 0.18?m RF CMOS process,in which a receiver and a transmitter are integrated.The transceiver ranged from system analysis,circuit design and chip measurement.The zero-IF receiver consists of a double-mode LNA,down-conversion mixers,DCOCs,LPFs and PGAs.The transceiver is supposed to have two modes: listen mode and talk mode,so as to meet the different requirements of the transceiver.In talk mode,a high linearity of the receiver front-end can avoid the carrier leakage.In talk mode,the worst-case receiver sensitivity is –83dBm and the 1-dB compression point is-2dBm.In listen mode,the linearity is not a problem since the transmitter's path is turned off and there is no carrier leakage.Therefore,the UHF RFID transceiver need a high sensitivity to receive weak signal from the antenna.In listen mode,the worst-case receiver sensitivity is –88dBm and the 1-dB compression point is-6dBm.The direct-conversion transmitter is composed of a DA,up-conversion mixers,LPFs and PGAs.The external power amplifier of the transmitter is used for high power transmission and isolation.An output power of 4d Bm by the transmitter to the external power amplifier can be produced from a power supply of 1.8V.Finally,the single-chip UHF RFID transceiver is demonstrated.Total die area including I/O pads is 9.25mm2.Measurement results show that: the input 1-dB compression point is-4dBm and power dissipation is 165 mA in talk mode;the input 1-dB compression point is-7dBm and power dissipation is 181 mA in listen mode.