A Single-Chip CMOS UHF RFID Reader Transceiver for Chinese Mobile Applications

Abstract

UHF RFID reader transceiver for Chinese local standard (840-845 MHz and 920-925 MHz), in concord with the protocols of EPC Class-1 Gen-2 and ISO/IEC 18000-6C, is presented. A highly linear RF front-end with low flicker noise, an on-chip self-jammer cancellation (SC) circuit with fast time-varying cut-off frequency and a DC-offset cancellation (DCOC) circuit are proposed to deal with the large self-jammer in the receiver. In the presence of 22 dBm PA output power, the receiver achieves a sensitivity of -79 dBm including the 15 dB loss of the directional coupler. A CMOS class-AB PA is integrated in the transmitter, with 22 dBm output power and 35% PAE. The spectrum mask achieves ACPR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> of -45 dBc and ACPR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> of -60 dBc . A sigma-delta fractional-N PLL with a single <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> VCO is also implemented for good phase noise (-126 dBc/Hz @ 1 MHz offset) and high frequency resolution within 1 kHz. This single-chip is fabricated in a 0.18 standard CMOS process. It occupies a silicon area of 13.5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and dissipates 203 mW from a 1.8 V supply voltage when transmitting 7.5 dBm output power.