A single-chip CMOS transceiver for UHF mobile RFID reader

This paper describes a single-antenna low-power single-chip radio frequency identification (RFID) reader for mobile phone applications. The reader integrates an RF transceiver, data converters, a digital baseband modem, an MPU, memory, and host interfaces. The direct conversion RF receiver architecture with the highly linear RF front-end circuit and DC offset cancellation circuit is used to give good immunity to the large transmitter leakage. It is suitable for a mobile phone reader with single-antenna architecture and low-power reader solution. The transmitter is implemented in the direct I/Q up-conversion architecture. The frequency synthesizer based on a fractional-N phase-locked-loop topology offering 900 MHz quadrature LO signals is also integrated with the RF transceiver. The reader is fabricated in a 0.18 mu m CMOS technology, and its die size is 4.5 mm x 5.3 mm including electrostatic discharge I/O pads. The reader consumes a total current of 89 mA apart from the external power amplifier with 1.8 V supply voltage. It achieves an 8 dBm P1dB, an 18.5 dBm IIP3, and a maximum transmitter output power of 4 dBm.